1351 lines
44 KiB
JavaScript
1351 lines
44 KiB
JavaScript
const fill_threshold = 1; // 1 is just enough for a workaround for Brave browser's farbling: https://github.com/1j01/jspaint/issues/184
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function get_brush_canvas_size(brush_size, brush_shape) {
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// brush_shape optional, only matters if it's circle
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// @TODO: does it actually still matter? the ellipse drawing code has changed
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// round to nearest even number in order for the canvas to be drawn centered at a point reasonably
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return Math.ceil(brush_size * (brush_shape === "circle" ? 2.1 : 1) / 2) * 2;
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}
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function render_brush(ctx, shape, size) {
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// USAGE NOTE: must be called outside of any other usage of op_canvas (because of draw_ellipse)
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if (shape.match(/diagonal/)) {
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size -= 0.4;
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}
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const mid_x = Math.round(ctx.canvas.width / 2);
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const left = Math.round(mid_x - size / 2);
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const right = Math.round(mid_x + size / 2);
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const mid_y = Math.round(ctx.canvas.height / 2);
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const top = Math.round(mid_y - size / 2);
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const bottom = Math.round(mid_y + size / 2);
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if (shape === "circle") {
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// @TODO: ideally _without_pattern_support
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draw_ellipse(ctx, left, top, size, size, false, true);
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// was useful for testing:
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// ctx.fillStyle = "red";
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// ctx.fillRect(mid_x, mid_y, 1, 1);
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} else if (shape === "square") {
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ctx.fillRect(left, top, ~~size, ~~size);
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} else if (shape === "diagonal") {
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draw_line_without_pattern_support(ctx, left, top, right, bottom);
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} else if (shape === "reverse_diagonal") {
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draw_line_without_pattern_support(ctx, left, bottom, right, top);
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} else if (shape === "horizontal") {
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draw_line_without_pattern_support(ctx, left, mid_y, size, mid_y);
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} else if (shape === "vertical") {
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draw_line_without_pattern_support(ctx, mid_x, top, mid_x, size);
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}
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}
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function draw_ellipse(ctx, x, y, w, h, stroke, fill) {
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const center_x = x + w / 2;
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const center_y = y + h / 2;
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if (aliasing) {
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const points = [];
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const step = 0.05;
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for (let theta = 0; theta < TAU; theta += step) {
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points.push({
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x: center_x + Math.cos(theta) * w / 2,
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y: center_y + Math.sin(theta) * h / 2,
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});
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}
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draw_polygon(ctx, points, stroke, fill);
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} else {
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ctx.beginPath();
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ctx.ellipse(center_x, center_y, Math.abs(w / 2), Math.abs(h / 2), 0, TAU, false);
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ctx.stroke();
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ctx.fill();
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}
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}
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function draw_rounded_rectangle(ctx, x, y, width, height, radius_x, radius_y, stroke, fill) {
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if (aliasing) {
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const points = [];
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const lineTo = (x, y) => {
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points.push({ x, y });
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};
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const arc = (x, y, radius_x, radius_y, startAngle, endAngle) => {
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const step = 0.05;
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for (let theta = startAngle; theta < endAngle; theta += step) {
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points.push({
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x: x + Math.cos(theta) * radius_x,
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y: y + Math.sin(theta) * radius_y,
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});
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}
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// not just doing `theta <= endAngle` above because that doesn't account for floating point rounding errors
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points.push({
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x: x + Math.cos(endAngle) * radius_x,
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y: y + Math.sin(endAngle) * radius_y,
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});
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};
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const x2 = x + width;
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const y2 = y + height;
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arc(x2 - radius_x, y + radius_y, radius_x, radius_y, TAU * 3 / 4, TAU, false);
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lineTo(x2, y2 - radius_y);
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arc(x2 - radius_x, y2 - radius_y, radius_x, radius_y, 0, TAU * 1 / 4, false);
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lineTo(x + radius_x, y2);
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arc(x + radius_x, y2 - radius_y, radius_x, radius_y, TAU * 1 / 4, TAU * 1 / 2, false);
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lineTo(x, y + radius_y);
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arc(x + radius_x, y + radius_y, radius_x, radius_y, TAU / 2, TAU * 3 / 4, false);
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draw_polygon(ctx, points, stroke, fill);
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} else {
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ctx.beginPath();
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ctx.moveTo(x + radius_x, y);
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ctx.lineTo(x + width - radius_x, y);
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ctx.quadraticCurveTo(x + width, y, x + width, y + radius_y);
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ctx.lineTo(x + width, y + height - radius_y);
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ctx.quadraticCurveTo(x + width, y + height, x + width - radius_x, y + height);
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ctx.lineTo(x + radius_x, y + height);
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ctx.quadraticCurveTo(x, y + height, x, y + height - radius_y);
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ctx.lineTo(x, y + radius_y);
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ctx.quadraticCurveTo(x, y, x + radius_x, y);
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ctx.closePath();
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if (stroke) {
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ctx.stroke();
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}
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if (fill) {
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ctx.fill();
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}
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}
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}
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// USAGE NOTE: must be called outside of any other usage of op_canvas (because of render_brush)
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// @TODO: protect against browser clearing canvases, invalidate cache
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const get_brush_canvas = memoize_synchronous_function((brush_shape, brush_size) => {
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const canvas_size = get_brush_canvas_size(brush_size, brush_shape);
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const brush_canvas = make_canvas(canvas_size, canvas_size);
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// brush_canvas.ctx.fillStyle = brush_canvas.ctx.strokeStyle = "black";
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render_brush(brush_canvas.ctx, brush_shape, brush_size);
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return brush_canvas;
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}, 20); // 12 brush tool options + current brush + current pencil + current eraser + current shape stroke + a few
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$G.on("invalidate-brush-canvases", () => {
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get_brush_canvas.clear_memo_cache();
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});
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// USAGE NOTE: must be called outside of any other usage of op_canvas (because of render_brush)
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const stamp_brush_canvas = (ctx, x, y, brush_shape, brush_size) => {
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const brush_canvas = get_brush_canvas(brush_shape, brush_size);
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const offset_x = -Math.ceil(brush_canvas.width / 2);
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const offset_y = -Math.ceil(brush_canvas.height / 2);
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ctx.drawImage(brush_canvas, x + offset_x, y + offset_y);
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};
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// USAGE NOTE: must be called outside of any other usage of op_canvas (because of render_brush)
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const get_circumference_points_for_brush = memoize_synchronous_function((brush_shape, brush_size) => {
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const brush_canvas = get_brush_canvas(brush_shape, brush_size);
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const image_data = brush_canvas.ctx.getImageData(0, 0, brush_canvas.width, brush_canvas.height);
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const at = (x, y) => (
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// coordinate checking is important so it doesn't wrap (if the brush abuts the edge of the canvas)
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x >= 0 && y >= 0 &&
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x < image_data.width && y < image_data.height &&
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image_data.data[(y * image_data.width + x) * 4 + 3] > 127
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);
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const offset_x = -Math.ceil(brush_canvas.width / 2);
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const offset_y = -Math.ceil(brush_canvas.height / 2);
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const points = [];
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for (let x = 0; x < image_data.width; x += 1) {
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for (let y = 0; y < image_data.height; y += 1) {
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if (at(x, y) && (
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!at(x, y - 1) ||
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!at(x, y + 1) ||
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!at(x - 1, y) ||
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!at(x + 1, y)
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)) {
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points.push({
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x: x + offset_x,
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y: y + offset_y,
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});
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}
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}
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}
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return points;
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});
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$G.on("invalidate-brush-canvases", () => {
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get_circumference_points_for_brush.clear_memo_cache();
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});
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let line_brush_canvas;
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// USAGE NOTE: must be called outside of any other usage of op_canvas (because of render_brush)
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function update_brush_for_drawing_lines(stroke_size) {
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if (aliasing && stroke_size > 1) {
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line_brush_canvas = get_brush_canvas("circle", stroke_size);
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}
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}
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function draw_line_without_pattern_support(ctx, x1, y1, x2, y2, stroke_size = 1) {
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if (aliasing) {
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if (stroke_size > 1) {
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bresenham_line(x1, y1, x2, y2, (x, y) => {
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ctx.drawImage(line_brush_canvas, ~~(x - line_brush_canvas.width / 2), ~~(y - line_brush_canvas.height / 2));
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});
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} else {
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bresenham_line(x1, y1, x2, y2, (x, y) => {
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ctx.fillRect(x, y, 1, 1);
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});
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}
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} else {
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ctx.beginPath();
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ctx.moveTo(x1, y1);
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ctx.lineTo(x2, y2);
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ctx.lineWidth = stroke_size;
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ctx.lineCap = "round";
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ctx.stroke();
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ctx.lineCap = "butt";
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}
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}
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function bresenham_line(x1, y1, x2, y2, callback) {
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// Bresenham's line algorithm
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x1 = ~~x1; x2 = ~~x2; y1 = ~~y1; y2 = ~~y2;
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const dx = Math.abs(x2 - x1);
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const dy = Math.abs(y2 - y1);
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const sx = (x1 < x2) ? 1 : -1;
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const sy = (y1 < y2) ? 1 : -1;
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let err = dx - dy;
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// eslint-disable-next-line no-constant-condition
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while (true) {
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callback(x1, y1);
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if (x1 === x2 && y1 === y2) break;
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const e2 = err * 2;
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if (e2 > -dy) { err -= dy; x1 += sx; }
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if (e2 < dx) { err += dx; y1 += sy; }
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}
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}
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function bresenham_dense_line(x1, y1, x2, y2, callback) {
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// Bresenham's line algorithm with a callback between going horizontal and vertical
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x1 = ~~x1; x2 = ~~x2; y1 = ~~y1; y2 = ~~y2;
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const dx = Math.abs(x2 - x1);
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const dy = Math.abs(y2 - y1);
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const sx = (x1 < x2) ? 1 : -1;
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const sy = (y1 < y2) ? 1 : -1;
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let err = dx - dy;
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// eslint-disable-next-line no-constant-condition
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while (true) {
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callback(x1, y1);
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if (x1 === x2 && y1 === y2) break;
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const e2 = err * 2;
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if (e2 > -dy) { err -= dy; x1 += sx; }
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callback(x1, y1);
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if (e2 < dx) { err += dx; y1 += sy; }
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}
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}
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function draw_fill_without_pattern_support(ctx, start_x, start_y, fill_r, fill_g, fill_b, fill_a) {
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// @TODO: split up processing in case it takes too long?
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// progress bar and abort button (outside of image-manipulation.js)
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// or at least just free up the main thread every once in a while
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// @TODO: speed up with typed arrays? https://hacks.mozilla.org/2011/12/faster-canvas-pixel-manipulation-with-typed-arrays/
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// could avoid endianness issues if only copying colors
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// the jsperf only shows ~15% improvement
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// maybe do something fancier like special-casing large chunks of single-color image
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// (octree? or just have a higher level stack of chunks to fill and check at if a chunk is homogeneous)
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const c_width = main_canvas.width;
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const c_height = main_canvas.height;
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start_x = Math.max(0, Math.min(Math.floor(start_x), c_width));
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start_y = Math.max(0, Math.min(Math.floor(start_y), c_height));
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const stack = [[start_x, start_y]];
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const id = ctx.getImageData(0, 0, c_width, c_height);
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let pixel_pos = (start_y * c_width + start_x) * 4;
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const start_r = id.data[pixel_pos + 0];
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const start_g = id.data[pixel_pos + 1];
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const start_b = id.data[pixel_pos + 2];
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const start_a = id.data[pixel_pos + 3];
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// @TODO: Allow flood-filling colors similar within fill threshold.
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// Right now it will cause an infinite loop if we don't stop early in this case.
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// As of writing, the fill threshold is very low, so this problem is unlikely to be noticed,
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// but it would be nice as a user-configurable option.
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if (
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Math.abs(fill_r - start_r) <= fill_threshold &&
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Math.abs(fill_g - start_g) <= fill_threshold &&
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Math.abs(fill_b - start_b) <= fill_threshold &&
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Math.abs(fill_a - start_a) <= fill_threshold
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) {
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return;
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}
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while (stack.length) {
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let new_pos;
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let x;
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let y;
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let reach_left;
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let reach_right;
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new_pos = stack.pop();
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x = new_pos[0];
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y = new_pos[1];
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pixel_pos = (y * c_width + x) * 4;
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while (should_fill_at(pixel_pos)) {
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y--;
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pixel_pos = (y * c_width + x) * 4;
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}
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reach_left = false;
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reach_right = false;
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// eslint-disable-next-line no-constant-condition
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while (true) {
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y++;
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pixel_pos = (y * c_width + x) * 4;
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if (!(y < c_height && should_fill_at(pixel_pos))) {
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break;
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}
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do_fill_at(pixel_pos);
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if (x > 0) {
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if (should_fill_at(pixel_pos - 4)) {
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if (!reach_left) {
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stack.push([x - 1, y]);
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reach_left = true;
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}
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} else if (reach_left) {
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reach_left = false;
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}
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}
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if (x < c_width - 1) {
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if (should_fill_at(pixel_pos + 4)) {
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if (!reach_right) {
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stack.push([x + 1, y]);
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reach_right = true;
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}
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} else if (reach_right) {
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reach_right = false;
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}
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}
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pixel_pos += c_width * 4;
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}
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}
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ctx.putImageData(id, 0, 0);
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function should_fill_at(pixel_pos) {
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return (
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// matches start color (i.e. region to fill)
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Math.abs(id.data[pixel_pos + 0] - start_r) <= fill_threshold &&
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Math.abs(id.data[pixel_pos + 1] - start_g) <= fill_threshold &&
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Math.abs(id.data[pixel_pos + 2] - start_b) <= fill_threshold &&
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Math.abs(id.data[pixel_pos + 3] - start_a) <= fill_threshold
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);
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}
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function do_fill_at(pixel_pos) {
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id.data[pixel_pos + 0] = fill_r;
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id.data[pixel_pos + 1] = fill_g;
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id.data[pixel_pos + 2] = fill_b;
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id.data[pixel_pos + 3] = fill_a;
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}
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}
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function draw_fill(ctx, start_x, start_y, swatch) {
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if (typeof swatch === "string") {
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const fill_rgba = get_rgba_from_color(swatch);
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draw_fill_without_pattern_support(ctx, start_x, start_y, fill_rgba[0], fill_rgba[1], fill_rgba[2], fill_rgba[3]);
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} else {
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const source_canvas = ctx.canvas;
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const fill_canvas = make_canvas(source_canvas.width, source_canvas.height);
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draw_fill_separately(source_canvas.ctx, fill_canvas.ctx, start_x, start_y, 255, 255, 255, 255);
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replace_colors_with_swatch(fill_canvas.ctx, swatch, 0, 0);
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ctx.drawImage(fill_canvas, 0, 0);
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}
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}
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function draw_fill_separately(source_ctx, dest_ctx, start_x, start_y, fill_r, fill_g, fill_b, fill_a) {
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if (fill_a === 0) {
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throw new Error("Filling with alpha of zero is not supported. Zero alpha is used for detecting whether a pixel has been visited.");
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}
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const c_width = main_canvas.width;
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const c_height = main_canvas.height;
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start_x = Math.max(0, Math.min(Math.floor(start_x), c_width));
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start_y = Math.max(0, Math.min(Math.floor(start_y), c_height));
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const stack = [[start_x, start_y]];
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const source_id = source_ctx.getImageData(0, 0, c_width, c_height);
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const dest_id = dest_ctx.getImageData(0, 0, c_width, c_height);
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let pixel_pos = (start_y * c_width + start_x) * 4;
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const start_r = source_id.data[pixel_pos + 0];
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const start_g = source_id.data[pixel_pos + 1];
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const start_b = source_id.data[pixel_pos + 2];
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const start_a = source_id.data[pixel_pos + 3];
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while (stack.length) {
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let new_pos;
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let x;
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let y;
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let reach_left;
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let reach_right;
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new_pos = stack.pop();
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x = new_pos[0];
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y = new_pos[1];
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pixel_pos = (y * c_width + x) * 4;
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while (should_fill_at(pixel_pos)) {
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y--;
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pixel_pos = (y * c_width + x) * 4;
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}
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reach_left = false;
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reach_right = false;
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// eslint-disable-next-line no-constant-condition
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while (true) {
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y++;
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pixel_pos = (y * c_width + x) * 4;
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if (!(y < c_height && should_fill_at(pixel_pos))) {
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break;
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}
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do_fill_at(pixel_pos);
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if (x > 0) {
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if (should_fill_at(pixel_pos - 4)) {
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if (!reach_left) {
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stack.push([x - 1, y]);
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reach_left = true;
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}
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} else if (reach_left) {
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reach_left = false;
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}
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}
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if (x < c_width - 1) {
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if (should_fill_at(pixel_pos + 4)) {
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if (!reach_right) {
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stack.push([x + 1, y]);
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reach_right = true;
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}
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} else if (reach_right) {
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reach_right = false;
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}
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}
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pixel_pos += c_width * 4;
|
|
}
|
|
}
|
|
dest_ctx.putImageData(dest_id, 0, 0);
|
|
|
|
function should_fill_at(pixel_pos) {
|
|
return (
|
|
// not reached yet
|
|
dest_id.data[pixel_pos + 3] === 0 &&
|
|
// and matches start color (i.e. region to fill)
|
|
(
|
|
Math.abs(source_id.data[pixel_pos + 0] - start_r) <= fill_threshold &&
|
|
Math.abs(source_id.data[pixel_pos + 1] - start_g) <= fill_threshold &&
|
|
Math.abs(source_id.data[pixel_pos + 2] - start_b) <= fill_threshold &&
|
|
Math.abs(source_id.data[pixel_pos + 3] - start_a) <= fill_threshold
|
|
)
|
|
);
|
|
}
|
|
|
|
function do_fill_at(pixel_pos) {
|
|
dest_id.data[pixel_pos + 0] = fill_r;
|
|
dest_id.data[pixel_pos + 1] = fill_g;
|
|
dest_id.data[pixel_pos + 2] = fill_b;
|
|
dest_id.data[pixel_pos + 3] = fill_a;
|
|
}
|
|
}
|
|
|
|
function replace_color_globally(image_data, from_r, from_g, from_b, from_a, to_r, to_g, to_b, to_a) {
|
|
if (
|
|
from_r === to_r &&
|
|
from_g === to_g &&
|
|
from_b === to_b &&
|
|
from_a === to_a
|
|
) {
|
|
return;
|
|
}
|
|
const { data } = image_data;
|
|
for (let i = 0; i < data.length; i += 4) {
|
|
if (
|
|
Math.abs(data[i + 0] - from_r) <= fill_threshold &&
|
|
Math.abs(data[i + 1] - from_g) <= fill_threshold &&
|
|
Math.abs(data[i + 2] - from_b) <= fill_threshold &&
|
|
Math.abs(data[i + 3] - from_a) <= fill_threshold
|
|
) {
|
|
data[i + 0] = to_r;
|
|
data[i + 1] = to_g;
|
|
data[i + 2] = to_b;
|
|
data[i + 3] = to_a;
|
|
}
|
|
}
|
|
}
|
|
|
|
function find_color_globally(source_image_data, dest_image_data, find_r, find_g, find_b, find_a) {
|
|
const source_data = source_image_data.data;
|
|
const dest_data = dest_image_data.data;
|
|
for (let i = 0; i < source_data.length; i += 4) {
|
|
if (
|
|
Math.abs(source_data[i + 0] - find_r) <= fill_threshold &&
|
|
Math.abs(source_data[i + 1] - find_g) <= fill_threshold &&
|
|
Math.abs(source_data[i + 2] - find_b) <= fill_threshold &&
|
|
Math.abs(source_data[i + 3] - find_a) <= fill_threshold
|
|
) {
|
|
dest_data[i + 0] = 255;
|
|
dest_data[i + 1] = 255;
|
|
dest_data[i + 2] = 255;
|
|
dest_data[i + 3] = 255;
|
|
}
|
|
}
|
|
}
|
|
|
|
function draw_noncontiguous_fill_without_pattern_support(ctx, x, y, fill_r, fill_g, fill_b, fill_a) {
|
|
x = Math.max(0, Math.min(Math.floor(x), ctx.canvas.width));
|
|
y = Math.max(0, Math.min(Math.floor(y), ctx.canvas.height));
|
|
const image_data = ctx.getImageData(0, 0, ctx.canvas.width, ctx.canvas.height);
|
|
const start_index = (y * image_data.width + x) * 4;
|
|
const start_r = image_data.data[start_index + 0];
|
|
const start_g = image_data.data[start_index + 1];
|
|
const start_b = image_data.data[start_index + 2];
|
|
const start_a = image_data.data[start_index + 3];
|
|
|
|
replace_color_globally(image_data, start_r, start_g, start_b, start_a, fill_r, fill_g, fill_b, fill_a);
|
|
|
|
ctx.putImageData(image_data, 0, 0);
|
|
}
|
|
|
|
function draw_noncontiguous_fill(ctx, x, y, swatch) {
|
|
if (typeof swatch === "string") {
|
|
const fill_rgba = get_rgba_from_color(swatch);
|
|
draw_noncontiguous_fill_without_pattern_support(ctx, x, y, fill_rgba[0], fill_rgba[1], fill_rgba[2], fill_rgba[3]);
|
|
} else {
|
|
const source_canvas = ctx.canvas;
|
|
const fill_canvas = make_canvas(source_canvas.width, source_canvas.height);
|
|
draw_noncontiguous_fill_separately(source_canvas.ctx, fill_canvas.ctx, x, y);
|
|
replace_colors_with_swatch(fill_canvas.ctx, swatch, 0, 0);
|
|
ctx.drawImage(fill_canvas, 0, 0);
|
|
}
|
|
}
|
|
|
|
function draw_noncontiguous_fill_separately(source_ctx, dest_ctx, x, y) {
|
|
x = Math.max(0, Math.min(Math.floor(x), source_ctx.canvas.width));
|
|
y = Math.max(0, Math.min(Math.floor(y), source_ctx.canvas.height));
|
|
const source_image_data = source_ctx.getImageData(0, 0, source_ctx.canvas.width, source_ctx.canvas.height);
|
|
const dest_image_data = dest_ctx.getImageData(0, 0, dest_ctx.canvas.width, dest_ctx.canvas.height);
|
|
const start_index = (y * source_image_data.width + x) * 4;
|
|
const start_r = source_image_data.data[start_index + 0];
|
|
const start_g = source_image_data.data[start_index + 1];
|
|
const start_b = source_image_data.data[start_index + 2];
|
|
const start_a = source_image_data.data[start_index + 3];
|
|
|
|
find_color_globally(source_image_data, dest_image_data, start_r, start_g, start_b, start_a);
|
|
|
|
dest_ctx.putImageData(dest_image_data, 0, 0);
|
|
}
|
|
|
|
function apply_image_transformation(meta, fn) {
|
|
// Apply an image transformation function to either the selection or the entire canvas
|
|
const original_canvas = selection ? selection.source_canvas : main_canvas;
|
|
|
|
const new_canvas = make_canvas(original_canvas.width, original_canvas.height);
|
|
|
|
const original_ctx = original_canvas.getContext("2d");
|
|
const new_ctx = new_canvas.getContext("2d");
|
|
|
|
fn(original_canvas, original_ctx, new_canvas, new_ctx);
|
|
|
|
if (selection) {
|
|
undoable({
|
|
name: `${meta.name} (${localize("Selection")})`,
|
|
icon: meta.icon,
|
|
soft: true,
|
|
}, () => {
|
|
selection.replace_source_canvas(new_canvas);
|
|
});
|
|
} else {
|
|
deselect();
|
|
cancel();
|
|
undoable({
|
|
name: meta.name,
|
|
icon: meta.icon,
|
|
}, () => {
|
|
saved = false;
|
|
update_title();
|
|
|
|
main_ctx.copy(new_canvas);
|
|
|
|
$canvas.trigger("update"); // update handles
|
|
});
|
|
}
|
|
}
|
|
|
|
function flip_horizontal() {
|
|
apply_image_transformation({
|
|
name: localize("Flip horizontal"),
|
|
icon: get_help_folder_icon("p_fliph.png"),
|
|
}, (original_canvas, original_ctx, new_canvas, new_ctx) => {
|
|
new_ctx.translate(new_canvas.width, 0);
|
|
new_ctx.scale(-1, 1);
|
|
new_ctx.drawImage(original_canvas, 0, 0);
|
|
});
|
|
}
|
|
|
|
function flip_vertical() {
|
|
apply_image_transformation({
|
|
name: localize("Flip vertical"),
|
|
icon: get_help_folder_icon("p_flipv.png"),
|
|
}, (original_canvas, original_ctx, new_canvas, new_ctx) => {
|
|
new_ctx.translate(0, new_canvas.height);
|
|
new_ctx.scale(1, -1);
|
|
new_ctx.drawImage(original_canvas, 0, 0);
|
|
});
|
|
}
|
|
|
|
function rotate(angle) {
|
|
apply_image_transformation({
|
|
name: `${localize("Rotate by angle")} ${angle / TAU * 360} ${localize("Degrees")}`,
|
|
icon: get_help_folder_icon(`p_rotate_${angle >= 0 ? "cw" : "ccw"}.png`),
|
|
}, (original_canvas, original_ctx, new_canvas, new_ctx) => {
|
|
new_ctx.save();
|
|
switch (angle) {
|
|
case TAU / 4:
|
|
case TAU * -3 / 4:
|
|
new_canvas.width = original_canvas.height;
|
|
new_canvas.height = original_canvas.width;
|
|
new_ctx.disable_image_smoothing();
|
|
new_ctx.translate(new_canvas.width, 0);
|
|
new_ctx.rotate(TAU / 4);
|
|
break;
|
|
case TAU / 2:
|
|
case TAU / -2:
|
|
new_ctx.translate(new_canvas.width, new_canvas.height);
|
|
new_ctx.rotate(TAU / 2);
|
|
break;
|
|
case TAU * 3 / 4:
|
|
case TAU / -4:
|
|
new_canvas.width = original_canvas.height;
|
|
new_canvas.height = original_canvas.width;
|
|
new_ctx.disable_image_smoothing();
|
|
new_ctx.translate(0, new_canvas.height);
|
|
new_ctx.rotate(TAU / -4);
|
|
break;
|
|
default: {
|
|
const w = original_canvas.width;
|
|
const h = original_canvas.height;
|
|
|
|
let bb_min_x = +Infinity;
|
|
let bb_max_x = -Infinity;
|
|
let bb_min_y = +Infinity;
|
|
let bb_max_y = -Infinity;
|
|
const corner = (x01, y01) => {
|
|
const x = Math.sin(-angle) * h * x01 + Math.cos(+angle) * w * y01;
|
|
const y = Math.sin(+angle) * w * y01 + Math.cos(-angle) * h * x01;
|
|
bb_min_x = Math.min(bb_min_x, x);
|
|
bb_max_x = Math.max(bb_max_x, x);
|
|
bb_min_y = Math.min(bb_min_y, y);
|
|
bb_max_y = Math.max(bb_max_y, y);
|
|
};
|
|
|
|
corner(0, 0);
|
|
corner(0, 1);
|
|
corner(1, 0);
|
|
corner(1, 1);
|
|
|
|
const bb_x = bb_min_x;
|
|
const bb_y = bb_min_y;
|
|
const bb_w = bb_max_x - bb_min_x;
|
|
const bb_h = bb_max_y - bb_min_y;
|
|
|
|
new_canvas.width = bb_w;
|
|
new_canvas.height = bb_h;
|
|
new_ctx.disable_image_smoothing();
|
|
|
|
if (!transparency) {
|
|
new_ctx.fillStyle = selected_colors.background;
|
|
new_ctx.fillRect(0, 0, new_canvas.width, new_canvas.height);
|
|
}
|
|
|
|
new_ctx.translate(-bb_x, -bb_y);
|
|
new_ctx.rotate(angle);
|
|
new_ctx.drawImage(original_canvas, 0, 0, w, h);
|
|
break;
|
|
}
|
|
}
|
|
new_ctx.drawImage(original_canvas, 0, 0);
|
|
new_ctx.restore();
|
|
});
|
|
}
|
|
|
|
function stretch_and_skew(x_scale, y_scale, h_skew, v_skew) {
|
|
apply_image_transformation({
|
|
name:
|
|
(h_skew !== 0 || v_skew !== 0) ? (
|
|
(x_scale !== 1 || y_scale !== 1) ? localize("Stretch and Skew") : localize("Skew")
|
|
) : localize("Stretch"),
|
|
icon: get_help_folder_icon(
|
|
(h_skew !== 0) ? "p_skew_h.png" :
|
|
(v_skew !== 0) ? "p_skew_v.png" :
|
|
(y_scale !== 1) ? (
|
|
(x_scale !== 1) ? "p_stretch_both.png" : "p_stretch_v.png"
|
|
) : "p_stretch_h.png"
|
|
),
|
|
}, (original_canvas, original_ctx, new_canvas, new_ctx) => {
|
|
const w = original_canvas.width * x_scale;
|
|
const h = original_canvas.height * y_scale;
|
|
|
|
let bb_min_x = +Infinity;
|
|
let bb_max_x = -Infinity;
|
|
let bb_min_y = +Infinity;
|
|
let bb_max_y = -Infinity;
|
|
const corner = (x01, y01) => {
|
|
const x = Math.tan(h_skew) * h * x01 + w * y01;
|
|
const y = Math.tan(v_skew) * w * y01 + h * x01;
|
|
bb_min_x = Math.min(bb_min_x, x);
|
|
bb_max_x = Math.max(bb_max_x, x);
|
|
bb_min_y = Math.min(bb_min_y, y);
|
|
bb_max_y = Math.max(bb_max_y, y);
|
|
};
|
|
|
|
corner(0, 0);
|
|
corner(0, 1);
|
|
corner(1, 0);
|
|
corner(1, 1);
|
|
|
|
const bb_x = bb_min_x;
|
|
const bb_y = bb_min_y;
|
|
const bb_w = bb_max_x - bb_min_x;
|
|
const bb_h = bb_max_y - bb_min_y;
|
|
|
|
new_canvas.width = Math.max(1, bb_w);
|
|
new_canvas.height = Math.max(1, bb_h);
|
|
new_ctx.disable_image_smoothing();
|
|
|
|
if (!transparency) {
|
|
new_ctx.fillStyle = selected_colors.background;
|
|
new_ctx.fillRect(0, 0, new_canvas.width, new_canvas.height);
|
|
}
|
|
|
|
new_ctx.save();
|
|
new_ctx.transform(
|
|
1, // x scale
|
|
Math.tan(v_skew), // vertical skew (skewY)
|
|
Math.tan(h_skew), // horizontal skew (skewX)
|
|
1, // y scale
|
|
-bb_x, // x translation
|
|
-bb_y // y translation
|
|
);
|
|
new_ctx.drawImage(original_canvas, 0, 0, w, h);
|
|
new_ctx.restore();
|
|
});
|
|
}
|
|
|
|
function invert_rgb(source_ctx, dest_ctx = source_ctx) {
|
|
const image_data = source_ctx.getImageData(0, 0, source_ctx.canvas.width, source_ctx.canvas.height);
|
|
for (let i = 0; i < image_data.data.length; i += 4) {
|
|
image_data.data[i + 0] = 255 - image_data.data[i + 0];
|
|
image_data.data[i + 1] = 255 - image_data.data[i + 1];
|
|
image_data.data[i + 2] = 255 - image_data.data[i + 2];
|
|
}
|
|
dest_ctx.putImageData(image_data, 0, 0);
|
|
}
|
|
|
|
function invert_monochrome(source_ctx, dest_ctx = source_ctx, monochrome_info = detect_monochrome(source_ctx)) {
|
|
const image_data = source_ctx.getImageData(0, 0, source_ctx.canvas.width, source_ctx.canvas.height);
|
|
// Note: values in pixel_array may be different on big endian vs little endian machines.
|
|
// Only rely on equality of values within the array.
|
|
// pixel_array is a performance optimization, to access whole pixels at a time instead of individual color channels.
|
|
const pixel_array = new Uint32Array(image_data.data.buffer);
|
|
if (monochrome_info.presentNonTransparentUint32s.length === 0) {
|
|
// Fully transparent.
|
|
// No change, and no need to copy the image to dest canvas to represent that lack of a change.
|
|
return;
|
|
}
|
|
if (monochrome_info.presentNonTransparentUint32s.length === 1) {
|
|
// Only one non-transparent color present in the image.
|
|
// Can't use just the information of what colors are in the canvas to invert, need to look at the palette.
|
|
// We could've done this in a unified way, but whatever!
|
|
// Personally, I think this is a CHARMINGLY poor solution.
|
|
// Maybe a little less so now that I added handling for transparency (i.e. Free-Form Select).
|
|
const color_1 = palette[0];
|
|
const color_2 = palette[14] || palette[1];
|
|
const color_1_rgba = get_rgba_from_color(color_1);
|
|
const present_rgba = monochrome_info.presentNonTransparentRGBAs[0];
|
|
if (
|
|
present_rgba[0] === color_1_rgba[0] &&
|
|
present_rgba[1] === color_1_rgba[1] &&
|
|
present_rgba[2] === color_1_rgba[2] &&
|
|
present_rgba[3] === color_1_rgba[3]
|
|
) {
|
|
dest_ctx.fillStyle = color_2;
|
|
} else {
|
|
dest_ctx.fillStyle = color_1;
|
|
}
|
|
if (monochrome_info.monochromeWithTransparency) {
|
|
dest_ctx.putImageData(image_data, 0, 0);
|
|
dest_ctx.globalCompositeOperation = "source-in";
|
|
}
|
|
dest_ctx.fillRect(0, 0, source_ctx.canvas.width, source_ctx.canvas.height);
|
|
return;
|
|
}
|
|
const [uint32_a, uint32_b] = monochrome_info.presentNonTransparentUint32s;
|
|
for (let i = 0, len = pixel_array.length; i < len; i += 1) {
|
|
if (pixel_array[i] === uint32_a) {
|
|
pixel_array[i] = uint32_b;
|
|
} else if (pixel_array[i] === uint32_b) {
|
|
pixel_array[i] = uint32_a;
|
|
}
|
|
}
|
|
dest_ctx.putImageData(image_data, 0, 0);
|
|
}
|
|
|
|
function threshold_black_and_white(ctx, threshold) {
|
|
const image_data = ctx.getImageData(0, 0, ctx.canvas.width, ctx.canvas.height);
|
|
for (let i = 0; i < image_data.data.length; i += 4) {
|
|
const white = (image_data.data[i + 0] + image_data.data[i + 1] + image_data.data[i + 2]) / 3 / 255 > threshold;
|
|
image_data.data[i + 0] = 255 * white;
|
|
image_data.data[i + 1] = 255 * white;
|
|
image_data.data[i + 2] = 255 * white;
|
|
image_data.data[i + 3] = 255;
|
|
}
|
|
ctx.putImageData(image_data, 0, 0);
|
|
}
|
|
|
|
function replace_colors_with_swatch(ctx, swatch, x_offset_from_global_canvas = 0, y_offset_from_global_canvas = 0) {
|
|
// USAGE NOTE: Context MUST be untranslated! (for the rectangle to cover the exact area of the canvas, and presumably for the pattern alignment as well)
|
|
// This function is mainly for patterns support (for black & white mode) but naturally handles solid colors as well.
|
|
ctx.globalCompositeOperation = "source-in";
|
|
ctx.fillStyle = swatch;
|
|
ctx.beginPath();
|
|
ctx.rect(0, 0, ctx.canvas.width, ctx.canvas.height);
|
|
ctx.save();
|
|
ctx.translate(-x_offset_from_global_canvas, -y_offset_from_global_canvas);
|
|
ctx.fill();
|
|
ctx.restore();
|
|
}
|
|
|
|
// adapted from https://github.com/Pomax/bezierjs
|
|
function compute_bezier(t, start_x, start_y, control_1_x, control_1_y, control_2_x, control_2_y, end_x, end_y) {
|
|
const mt = 1 - t;
|
|
const mt2 = mt * mt;
|
|
const t2 = t * t;
|
|
let a, b, c, d = 0;
|
|
|
|
a = mt2 * mt;
|
|
b = mt2 * t * 3;
|
|
c = mt * t2 * 3;
|
|
d = t * t2;
|
|
|
|
return {
|
|
x: a * start_x + b * control_1_x + c * control_2_x + d * end_x,
|
|
y: a * start_y + b * control_1_y + c * control_2_y + d * end_y
|
|
};
|
|
}
|
|
|
|
function draw_bezier_curve_without_pattern_support(ctx, start_x, start_y, control_1_x, control_1_y, control_2_x, control_2_y, end_x, end_y, stroke_size) {
|
|
const steps = 100;
|
|
let point_a = { x: start_x, y: start_y };
|
|
for (let t = 0; t < 1; t += 1 / steps) {
|
|
const point_b = compute_bezier(t, start_x, start_y, control_1_x, control_1_y, control_2_x, control_2_y, end_x, end_y);
|
|
// @TODO: carry "error" from Bresenham line algorithm between iterations? and/or get a proper Bezier drawing algorithm
|
|
draw_line_without_pattern_support(ctx, point_a.x, point_a.y, point_b.x, point_b.y, stroke_size);
|
|
point_a = point_b;
|
|
}
|
|
}
|
|
function draw_quadratic_curve(ctx, start_x, start_y, control_x, control_y, end_x, end_y, stroke_size) {
|
|
draw_bezier_curve(ctx, start_x, start_y, control_x, control_y, control_x, control_y, end_x, end_y, stroke_size);
|
|
}
|
|
|
|
function draw_bezier_curve(ctx, start_x, start_y, control_1_x, control_1_y, control_2_x, control_2_y, end_x, end_y, stroke_size) {
|
|
// could calculate bounds of Bezier curve with something like bezier-js
|
|
// but just using the control points should be fine
|
|
const min_x = Math.min(start_x, control_1_x, control_2_x, end_x);
|
|
const min_y = Math.min(start_y, control_1_y, control_2_y, end_y);
|
|
const max_x = Math.max(start_x, control_1_x, control_2_x, end_x);
|
|
const max_y = Math.max(start_y, control_1_y, control_2_y, end_y);
|
|
draw_with_swatch(ctx, min_x, min_y, max_x, max_y, stroke_color, op_ctx_2d => {
|
|
draw_bezier_curve_without_pattern_support(op_ctx_2d, start_x, start_y, control_1_x, control_1_y, control_2_x, control_2_y, end_x, end_y, stroke_size);
|
|
});
|
|
}
|
|
function draw_line(ctx, x1, y1, x2, y2, stroke_size) {
|
|
const min_x = Math.min(x1, x2);
|
|
const min_y = Math.min(y1, y2);
|
|
const max_x = Math.max(x1, x2);
|
|
const max_y = Math.max(y1, y2);
|
|
draw_with_swatch(ctx, min_x, min_y, max_x, max_y, stroke_color, op_ctx_2d => {
|
|
draw_line_without_pattern_support(op_ctx_2d, x1, y1, x2, y2, stroke_size);
|
|
});
|
|
// also works:
|
|
// draw_line_strip(ctx, [{x: x1, y: y1}, {x: x2, y: y2}]);
|
|
}
|
|
|
|
let grid_pattern;
|
|
function draw_grid(ctx, scale) {
|
|
const pattern_size = Math.floor(scale); // @TODO: try ceil too
|
|
if (!grid_pattern || grid_pattern.width !== pattern_size || grid_pattern.height !== pattern_size) {
|
|
const grid_pattern_canvas = make_canvas(pattern_size, pattern_size);
|
|
const dark_gray = "#808080";
|
|
const light_gray = "#c0c0c0";
|
|
grid_pattern_canvas.ctx.fillStyle = dark_gray;
|
|
grid_pattern_canvas.ctx.fillRect(0, 0, 1, pattern_size);
|
|
grid_pattern_canvas.ctx.fillStyle = dark_gray;
|
|
grid_pattern_canvas.ctx.fillRect(0, 0, pattern_size, 1);
|
|
grid_pattern_canvas.ctx.fillStyle = light_gray;
|
|
for (let i = 1; i < pattern_size; i += 2) {
|
|
grid_pattern_canvas.ctx.fillRect(i, 0, 1, 1);
|
|
grid_pattern_canvas.ctx.fillRect(0, i, 1, 1);
|
|
}
|
|
grid_pattern = ctx.createPattern(grid_pattern_canvas, "repeat");
|
|
}
|
|
ctx.save();
|
|
ctx.rect(0, 0, ctx.canvas.width, ctx.canvas.height);
|
|
if (scale !== pattern_size) {
|
|
ctx.translate(-0.5, -0.75); // hand picked to look "good" at 110% in chrome
|
|
// might be better to just hide the grid in some more cases tho
|
|
// ...@TODO: if I can get helper layer to be pixel aligned, I can probably remove this
|
|
}
|
|
ctx.scale(scale / pattern_size, scale / pattern_size);
|
|
ctx.enable_image_smoothing();
|
|
ctx.fillStyle = grid_pattern;
|
|
ctx.fill();
|
|
ctx.restore();
|
|
}
|
|
|
|
(() => {
|
|
|
|
// the dashes of the border are sized such that at 4x zoom,
|
|
// they're squares equal to one canvas pixel
|
|
// they're offset by a screen pixel tho from the canvas pixel cells
|
|
|
|
const svg_for_creating_matrices = document.createElementNS("http://www.w3.org/2000/svg", "svg");
|
|
|
|
const horizontal_pattern_canvas = make_canvas(8, 4);
|
|
const vertical_pattern_canvas = make_canvas(4, 8);
|
|
let horizontal_pattern;
|
|
let vertical_pattern;
|
|
|
|
function draw_dashes(ctx, x, y, go_x, go_y, scale, translate_x, translate_y) {
|
|
if (!vertical_pattern) {
|
|
horizontal_pattern_canvas.ctx.fillStyle = "white";
|
|
horizontal_pattern_canvas.ctx.fillRect(4, 0, 4, 4);
|
|
vertical_pattern_canvas.ctx.fillStyle = "white";
|
|
vertical_pattern_canvas.ctx.fillRect(0, 4, 4, 4);
|
|
horizontal_pattern = ctx.createPattern(horizontal_pattern_canvas, "repeat");
|
|
vertical_pattern = ctx.createPattern(vertical_pattern_canvas, "repeat");
|
|
}
|
|
|
|
const dash_width = 1;
|
|
const hairline_width = 1 / scale; // size of a screen pixel
|
|
|
|
ctx.save();
|
|
|
|
ctx.scale(scale, scale);
|
|
ctx.translate(translate_x, translate_y);
|
|
|
|
ctx.translate(x, y);
|
|
ctx.globalCompositeOperation = "difference";
|
|
|
|
|
|
if (go_x > 0) {
|
|
const matrix = svg_for_creating_matrices.createSVGMatrix();
|
|
if (horizontal_pattern.setTransform) { // not supported by Edge as of 2019-12-04
|
|
horizontal_pattern.setTransform(matrix.translate(-x, -y).translate(hairline_width, 0).scale(1 / scale));
|
|
}
|
|
ctx.fillStyle = horizontal_pattern;
|
|
ctx.fillRect(0, 0, go_x, dash_width);
|
|
} else if (go_y > 0) {
|
|
const matrix = svg_for_creating_matrices.createSVGMatrix();
|
|
if (vertical_pattern.setTransform) { // not supported by Edge as of 2019-12-04
|
|
vertical_pattern.setTransform(matrix.translate(-x, -y).translate(0, hairline_width).scale(1 / scale));
|
|
}
|
|
ctx.fillStyle = vertical_pattern;
|
|
ctx.fillRect(0, 0, dash_width, go_y);
|
|
}
|
|
ctx.restore();
|
|
}
|
|
|
|
window.draw_selection_box = (ctx, rect_x, rect_y, rect_w, rect_h, scale, translate_x, translate_y) => {
|
|
draw_dashes(ctx, rect_x, rect_y, rect_w - 1, 0, scale, translate_x, translate_y); // top
|
|
if (rect_h === 1) {
|
|
draw_dashes(ctx, rect_x, rect_y, 0, 1, scale, translate_x, translate_y); // left
|
|
} else {
|
|
draw_dashes(ctx, rect_x, rect_y + 1, 0, rect_h - 2, scale, translate_x, translate_y); // left
|
|
}
|
|
draw_dashes(ctx, rect_x + rect_w - 1, rect_y, 0, rect_h, scale, translate_x, translate_y); // right
|
|
draw_dashes(ctx, rect_x, rect_y + rect_h - 1, rect_w - 1, 0, scale, translate_x, translate_y); // bottom
|
|
draw_dashes(ctx, rect_x, rect_y + 1, 0, 1, scale, translate_x, translate_y); // top left dangling bit???
|
|
};
|
|
|
|
})();
|
|
|
|
(() => {
|
|
|
|
const tessy = (function initTesselator() {
|
|
// function called for each vertex of tesselator output
|
|
function vertex_callback(data, poly_vert_array) {
|
|
// window.console && console.log(data[0], data[1]);
|
|
poly_vert_array[poly_vert_array.length] = data[0];
|
|
poly_vert_array[poly_vert_array.length] = data[1];
|
|
}
|
|
function begin_callback(type) {
|
|
if (type !== libtess.primitiveType.GL_TRIANGLES) {
|
|
window.console && console.log(`Expected TRIANGLES but got type: ${type}`);
|
|
}
|
|
}
|
|
function error_callback(errno) {
|
|
window.console && console.log('error callback');
|
|
window.console && console.log(`error number: ${errno}`);
|
|
}
|
|
// callback for when segments intersect and must be split
|
|
function combine_callback(coords/*, data, weight*/) {
|
|
// window.console && console.log('combine callback');
|
|
return [coords[0], coords[1], coords[2]];
|
|
}
|
|
function edge_callback(/*flag*/) {
|
|
// don't really care about the flag, but need no-strip/no-fan behavior
|
|
// window.console && console.log('edge flag: ' + flag);
|
|
}
|
|
|
|
const tessy = new libtess.GluTesselator();
|
|
// tessy.gluTessProperty(libtess.gluEnum.GLU_TESS_WINDING_RULE, libtess.windingRule.GLU_TESS_WINDING_POSITIVE);
|
|
tessy.gluTessCallback(libtess.gluEnum.GLU_TESS_VERTEX_DATA, vertex_callback);
|
|
tessy.gluTessCallback(libtess.gluEnum.GLU_TESS_BEGIN, begin_callback);
|
|
tessy.gluTessCallback(libtess.gluEnum.GLU_TESS_ERROR, error_callback);
|
|
tessy.gluTessCallback(libtess.gluEnum.GLU_TESS_COMBINE, combine_callback);
|
|
tessy.gluTessCallback(libtess.gluEnum.GLU_TESS_EDGE_FLAG, edge_callback);
|
|
|
|
return tessy;
|
|
}());
|
|
|
|
function triangulate(contours) {
|
|
// libtess will take 3d verts and flatten to a plane for tesselation
|
|
// since only doing 2d tesselation here, provide z=1 normal to skip
|
|
// iterating over verts only to get the same answer.
|
|
tessy.gluTessNormal(0, 0, 1);
|
|
|
|
const triangleVerts = [];
|
|
tessy.gluTessBeginPolygon(triangleVerts);
|
|
|
|
for (let i = 0; i < contours.length; i++) {
|
|
tessy.gluTessBeginContour();
|
|
const contour = contours[i];
|
|
for (let j = 0; j < contour.length; j += 2) {
|
|
const coords = [contour[j], contour[j + 1], 0];
|
|
tessy.gluTessVertex(coords, coords);
|
|
}
|
|
tessy.gluTessEndContour();
|
|
}
|
|
|
|
tessy.gluTessEndPolygon();
|
|
|
|
return triangleVerts;
|
|
}
|
|
|
|
|
|
let gl;
|
|
let positionLoc;
|
|
|
|
function initWebGL(canvas) {
|
|
try {
|
|
gl = canvas.getContext('webgl', { antialias: false });
|
|
} catch (error) {
|
|
show_error_message("Failed to get WebGL context. You may need to refresh the web page, or restart your computer.", error);
|
|
return;
|
|
}
|
|
|
|
if (!gl) {
|
|
show_error_message("Failed to get WebGL context. You may need to refresh the web page, or restart your computer.");
|
|
return;
|
|
}
|
|
|
|
window.WEBGL_lose_context = gl.getExtension("WEBGL_lose_context");
|
|
|
|
const program = createShaderProgram();
|
|
positionLoc = gl.getAttribLocation(program, 'position');
|
|
gl.enableVertexAttribArray(positionLoc);
|
|
}
|
|
|
|
function initArrayBuffer(triangleVertexCoords) {
|
|
// put triangle coordinates into a WebGL ArrayBuffer and bind to
|
|
// shader's 'position' attribute variable
|
|
const rawData = new Float32Array(triangleVertexCoords);
|
|
const polygonArrayBuffer = gl.createBuffer();
|
|
gl.bindBuffer(gl.ARRAY_BUFFER, polygonArrayBuffer);
|
|
gl.bufferData(gl.ARRAY_BUFFER, rawData, gl.STATIC_DRAW);
|
|
gl.vertexAttribPointer(positionLoc, 2, gl.FLOAT, false, 0, 0);
|
|
|
|
return triangleVertexCoords.length / 2;
|
|
}
|
|
|
|
function createShaderProgram() {
|
|
// create vertex shader
|
|
const vertexSrc = [
|
|
'attribute vec4 position;',
|
|
'void main() {',
|
|
' /* already in normalized coordinates, so just pass through */',
|
|
' gl_Position = position;',
|
|
'}'
|
|
].join('');
|
|
const vertexShader = gl.createShader(gl.VERTEX_SHADER);
|
|
gl.shaderSource(vertexShader, vertexSrc);
|
|
gl.compileShader(vertexShader);
|
|
|
|
if (!gl.getShaderParameter(vertexShader, gl.COMPILE_STATUS)) {
|
|
window.console && console.log(
|
|
`Vertex shader failed to compile. Log: ${gl.getShaderInfoLog(vertexShader)}`
|
|
);
|
|
}
|
|
|
|
// create fragment shader
|
|
const fragmentSrc = [
|
|
'precision mediump float;',
|
|
'void main() {',
|
|
' gl_FragColor = vec4(0, 0, 0, 1);',
|
|
'}'
|
|
].join('');
|
|
const fragmentShader = gl.createShader(gl.FRAGMENT_SHADER);
|
|
gl.shaderSource(fragmentShader, fragmentSrc);
|
|
gl.compileShader(fragmentShader);
|
|
|
|
if (!gl.getShaderParameter(fragmentShader, gl.COMPILE_STATUS)) {
|
|
window.console && console.log(
|
|
`Fragment shader failed to compile. Log: ${gl.getShaderInfoLog(fragmentShader)}`
|
|
);
|
|
}
|
|
|
|
// link shaders to create our program
|
|
const program = gl.createProgram();
|
|
gl.attachShader(program, vertexShader);
|
|
gl.attachShader(program, fragmentShader);
|
|
gl.linkProgram(program);
|
|
|
|
gl.useProgram(program);
|
|
|
|
return program;
|
|
}
|
|
|
|
|
|
const op_canvas_webgl = document.createElement('canvas');
|
|
const op_canvas_2d = document.createElement('canvas');
|
|
const op_ctx_2d = op_canvas_2d.getContext("2d");
|
|
|
|
initWebGL(op_canvas_webgl);
|
|
let warning_tid;
|
|
op_canvas_webgl.addEventListener("webglcontextlost", (e) => {
|
|
e.preventDefault();
|
|
window.console && console.warn("WebGL context lost");
|
|
clamp_brush_sizes();
|
|
|
|
warning_tid = setTimeout(() => {
|
|
show_error_message("The WebGL context was lost. You may need to refresh the web page, or restart your computer.");
|
|
}, 3000);
|
|
}, false);
|
|
op_canvas_webgl.addEventListener("webglcontextrestored", () => {
|
|
initWebGL(op_canvas_webgl);
|
|
|
|
window.console && console.warn("WebGL context restored");
|
|
clearTimeout(warning_tid);
|
|
|
|
clamp_brush_sizes();
|
|
|
|
// brushes rendered using WebGL may be invalid (i.e. invisible) since the context was lost
|
|
// invalidate the cache(s) so that brushes will be re-rendered now that WebGL is restored
|
|
$G.triggerHandler("invalidate-brush-canvases");
|
|
|
|
$G.triggerHandler("redraw-tool-options-because-webglcontextrestored");
|
|
}, false);
|
|
|
|
function clamp_brush_sizes() {
|
|
const max_size = 100;
|
|
if (brush_size > max_size) {
|
|
brush_size = max_size;
|
|
show_error_message(`Brush size clamped to ${max_size}`);
|
|
}
|
|
if (pencil_size > max_size) {
|
|
pencil_size = max_size;
|
|
show_error_message(`Pencil size clamped to ${max_size}`);
|
|
}
|
|
if (stroke_size > max_size) {
|
|
stroke_size = max_size;
|
|
show_error_message(`Stroke size clamped to ${max_size}`);
|
|
}
|
|
}
|
|
|
|
window.draw_line_strip = (ctx, points) => {
|
|
draw_polygon_or_line_strip(ctx, points, true, false, false);
|
|
};
|
|
window.draw_polygon = (ctx, points, stroke, fill) => {
|
|
draw_polygon_or_line_strip(ctx, points, stroke, fill, true);
|
|
};
|
|
|
|
function draw_polygon_or_line_strip(ctx, points, stroke, fill, close_path) {
|
|
if (!gl) {
|
|
show_error_message("Failed to get WebGL context. You may need to refresh the web page, or restart your computer.");
|
|
return; // @TODO: don't pollute brush cache with empty brushes (also maybe fallback to 2D canvas rendering)
|
|
}
|
|
|
|
// this must be before stuff is done with op_canvas
|
|
// otherwise update_brush_for_drawing_lines calls render_brush calls draw_ellipse calls draw_polygon calls draw_polygon_or_line_strip
|
|
// trying to use the same op_canvas
|
|
// (also, avoiding infinite recursion by checking for stroke; assuming brushes will never have outlines)
|
|
if (stroke && stroke_size > 1) {
|
|
update_brush_for_drawing_lines(stroke_size);
|
|
}
|
|
|
|
const stroke_color = ctx.strokeStyle;
|
|
const fill_color = ctx.fillStyle;
|
|
|
|
const numPoints = points.length;
|
|
const numCoords = numPoints * 2;
|
|
|
|
if (numPoints === 0) {
|
|
return;
|
|
}
|
|
|
|
let x_min = +Infinity;
|
|
let x_max = -Infinity;
|
|
let y_min = +Infinity;
|
|
let y_max = -Infinity;
|
|
for (const { x, y } of points) {
|
|
x_min = Math.min(x, x_min);
|
|
x_max = Math.max(x, x_max);
|
|
y_min = Math.min(y, y_min);
|
|
y_max = Math.max(y, y_max);
|
|
}
|
|
x_max += 1;
|
|
y_max += 1;
|
|
x_min -= 1;
|
|
y_min -= 1;
|
|
|
|
op_canvas_webgl.width = x_max - x_min;
|
|
op_canvas_webgl.height = y_max - y_min;
|
|
gl.viewport(0, 0, op_canvas_webgl.width, op_canvas_webgl.height);
|
|
|
|
const coords = new Float32Array(numCoords);
|
|
for (let i = 0; i < numPoints; i++) {
|
|
coords[i * 2 + 0] = (points[i].x - x_min) / op_canvas_webgl.width * 2 - 1;
|
|
coords[i * 2 + 1] = 1 - (points[i].y - y_min) / op_canvas_webgl.height * 2;
|
|
// @TODO: investigate: does this cause resolution/information loss? can we change the coordinate system?
|
|
}
|
|
|
|
if (fill) {
|
|
const contours = [coords];
|
|
const polyTriangles = triangulate(contours);
|
|
let numVertices = initArrayBuffer(polyTriangles);
|
|
gl.clear(gl.COLOR_BUFFER_BIT);
|
|
gl.drawArrays(gl.TRIANGLES, 0, numVertices);
|
|
|
|
op_canvas_2d.width = op_canvas_webgl.width;
|
|
op_canvas_2d.height = op_canvas_webgl.height;
|
|
|
|
op_ctx_2d.drawImage(op_canvas_webgl, 0, 0);
|
|
replace_colors_with_swatch(op_ctx_2d, fill_color, x_min, y_min);
|
|
ctx.drawImage(op_canvas_2d, x_min, y_min);
|
|
}
|
|
if (stroke) {
|
|
if (stroke_size > 1) {
|
|
const stroke_margin = ~~(stroke_size * 1.1);
|
|
|
|
const op_canvas_x = x_min - stroke_margin;
|
|
const op_canvas_y = y_min - stroke_margin;
|
|
|
|
op_canvas_2d.width = x_max - x_min + stroke_margin * 2;
|
|
op_canvas_2d.height = y_max - y_min + stroke_margin * 2;
|
|
for (let i = 0; i < numPoints - (close_path ? 0 : 1); i++) {
|
|
const point_a = points[i];
|
|
const point_b = points[(i + 1) % numPoints];
|
|
// Note: update_brush_for_drawing_lines way above
|
|
draw_line_without_pattern_support(
|
|
op_ctx_2d,
|
|
point_a.x - op_canvas_x,
|
|
point_a.y - op_canvas_y,
|
|
point_b.x - op_canvas_x,
|
|
point_b.y - op_canvas_y,
|
|
stroke_size
|
|
);
|
|
}
|
|
|
|
replace_colors_with_swatch(op_ctx_2d, stroke_color, op_canvas_x, op_canvas_y);
|
|
ctx.drawImage(op_canvas_2d, op_canvas_x, op_canvas_y);
|
|
} else {
|
|
let numVertices = initArrayBuffer(coords);
|
|
gl.clear(gl.COLOR_BUFFER_BIT);
|
|
gl.drawArrays(close_path ? gl.LINE_LOOP : gl.LINE_STRIP, 0, numVertices);
|
|
|
|
op_canvas_2d.width = op_canvas_webgl.width;
|
|
op_canvas_2d.height = op_canvas_webgl.height;
|
|
|
|
op_ctx_2d.drawImage(op_canvas_webgl, 0, 0);
|
|
replace_colors_with_swatch(op_ctx_2d, stroke_color, x_min, y_min);
|
|
ctx.drawImage(op_canvas_2d, x_min, y_min);
|
|
}
|
|
}
|
|
}
|
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window.copy_contents_within_polygon = (canvas, points, x_min, y_min, x_max, y_max) => {
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// Copy the contents of the given canvas within the polygon given by points bounded by x/y_min/max
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x_max = Math.max(x_max, x_min + 1);
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y_max = Math.max(y_max, y_min + 1);
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const width = x_max - x_min;
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const height = y_max - y_min;
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// @TODO: maybe have the cutout only the width/height of the bounds
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// const cutout = make_canvas(width, height);
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const cutout = make_canvas(canvas);
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cutout.ctx.save();
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cutout.ctx.globalCompositeOperation = "destination-in";
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draw_polygon(cutout.ctx, points, false, true);
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cutout.ctx.restore();
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const cutout_crop = make_canvas(width, height);
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cutout_crop.ctx.drawImage(cutout, x_min, y_min, width, height, 0, 0, width, height);
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return cutout_crop;
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}
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// @TODO: maybe shouldn't be external...
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window.draw_with_swatch = (ctx, x_min, y_min, x_max, y_max, swatch, callback) => {
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const stroke_margin = ~~(stroke_size * 1.1);
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x_max = Math.max(x_max, x_min + 1);
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y_max = Math.max(y_max, y_min + 1);
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op_canvas_2d.width = x_max - x_min + stroke_margin * 2;
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op_canvas_2d.height = y_max - y_min + stroke_margin * 2;
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const x = x_min - stroke_margin;
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const y = y_min - stroke_margin;
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op_ctx_2d.save();
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op_ctx_2d.translate(-x, -y);
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callback(op_ctx_2d);
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op_ctx_2d.restore(); // for replace_colors_with_swatch!
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replace_colors_with_swatch(op_ctx_2d, swatch, x, y);
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ctx.drawImage(op_canvas_2d, x, y);
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|
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// for debug:
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// ctx.fillStyle = "rgba(255, 0, 255, 0.1)";
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// ctx.fillRect(x, y, op_canvas_2d.width, op_canvas_2d.height);
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}
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|
})();
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