radex
/
jspaint
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Use WebGL for freeform select tool

main
Isaiah Odhner 2018-06-18 15:28:27 -04:00
parent 3a15a7a917
commit c1d99d03c7
3 changed files with 38 additions and 98 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
src/Selection.js
View File

@ -140,6 +140,7 @@ Selection.prototype.cut_out_background = function(){
// this is mainly in order to support patterns as the background color
// NOTE: must come before cutout canvas is modified
var colored_cutout = new Canvas(cutout);
// TODO: use replace_colors_with_swatch with sel.x, sel.y to support patterns properly (fix the offset)
colored_cutout.ctx.globalCompositeOperation = "source-in";
colored_cutout.ctx.fillStyle = colors.background;
colored_cutout.ctx.fillRect(0, 0, colored_cutout.width, colored_cutout.height);

132
src/image-manipulation.js
View File

@ -534,103 +534,6 @@ function stretch_and_skew(xscale, yscale, hsa, vsa){
});
}
function cut_polygon(points, x_min, y_min, x_max, y_max, from_canvas){
// Cut out the polygon given by points bounded by x/y_min/max from from_canvas
// TODO: use webgl polygon code
from_canvas = from_canvas || canvas;
var X_MIN = x_min; // || 0;
var X_MAX = x_max; // || canvas.width;
var Y_MIN = y_min; // || 0;
var Y_MAX = y_max; // || canvas.height;
var WIDTH = X_MAX - X_MIN;
var HEIGHT = Y_MAX - Y_MIN;
var cutout = new Canvas(WIDTH, HEIGHT);
// Take image data from source canvas context
var id_src = from_canvas.ctx.getImageData(X_MIN, Y_MIN, WIDTH, HEIGHT);
// Create image data to draw the polygon onto
var id_dest = cutout.ctx.createImageData(WIDTH, HEIGHT);
// Loosely based off of some public-domain code by Darel Rex Finley, 2007
var nodes; // length of the nodeX array
var nodeX = new Array(points.length);
var swap;
var i, j;
//var edge_points = [];
// Loop through the rows of the image.
for(var y = Y_MIN; y < Y_MAX; y++){
// Build a list of nodes.
// (In this context, "nodes" are one-dimensional points of intersection)
// (Also, `nodes` is treated as the length of the nodeX array)
nodes = 0;
j = points.length - 1;
for(i = 0; i < points.length; i++){
if(
points[i].y < y && points[j].y >= y ||
points[j].y < y && points[i].y >= y
){
nodeX[nodes++] =
points[i].x +
(y - points[i].y) /
(points[j].y - points[i].y) *
(points[j].x - points[i].x);
}
j = i;
}
// Sort the nodes, via a simple “Bubble” sort.
i = 0;
while(i < nodes-1){
if(nodeX[i] > nodeX[i+1]){
swap = nodeX[i];
nodeX[i] = nodeX[i+1];
nodeX[i+1] = swap;
if(i){ i--; }
}else{
i++;
}
}
// Browsers optimize sorting numbers, so just use Array::sort
/*nodeX.sort(function(a, b){
return a - b;
});*/
// But this array can contain undefineds [citation needed]
// It's not defined by its length but by the variable `nodes`
// Fill the pixels between node pairs.
for(i = 0; i < nodes; i += 2){
if(nodeX[i+0] >= X_MAX) break;
if(nodeX[i+1] > X_MIN){
if(nodeX[i+0] < X_MIN) nodeX[i+0] = X_MIN;
if(nodeX[i+1] > X_MAX) nodeX[i+1] = X_MAX;
for(var x = nodeX[i]; x < nodeX[i+1]; x++){
// fill pixel at (x, y)
var idi = ((y-Y_MIN)*WIDTH + ~~(x-X_MIN))*4;
id_dest.data[idi+0] = id_src.data[idi+0];
id_dest.data[idi+1] = id_src.data[idi+1];
id_dest.data[idi+2] = id_src.data[idi+2];
id_dest.data[idi+3] = id_src.data[idi+3];
}
//edge_points.push({x: nodeX[i+0], y: y});
//edge_points.push({x: nodeX[i+1], y: y});
}
}
}
// Done boom okay
cutout.ctx.putImageData(id_dest, 0, 0);
//cutout.edge_points = edge_points;
return cutout;
}
function replace_colors_with_swatch(ctx, swatch, x_offset_from_global_canvas, y_offset_from_global_canvas){
// mainly for patterns support (for black & white mode)
ctx.globalCompositeOperation = "source-in";
@ -933,4 +836,39 @@ function draw_quadratic_curve(ctx, start_x, start_y, control_x, control_y, end_x
}
};
window.cut_polygon = function(points, x_min, y_min, x_max, y_max, from_canvas){
// Copy the contents of the given canvas within the polygon given by points bounded by x/y_min/max
var width = x_max - x_min;
var height = y_max - y_min;
// TODO: maybe have the cutout only the width/height of the bounds
// var cutout = new Canvas(width, height);
// var cutout = new Canvas(from_canvas.width, from_canvas.height);
var cutout = new Canvas(from_canvas);
cutout.ctx.save();
cutout.ctx.globalCompositeOperation = "destination-in";
draw_polygon(cutout.ctx, points, false, true);
cutout.ctx.restore();
// take the contents of the polygon from the canvas
// todo: handle transparency the source-in/atop isn't gonna work for both of these situations is it?
// cutout.ctx.save();
// cutout.ctx.globalCompositeOperation = "source-atop";
// // cutout.ctx.drawImage(from_canvas, 0, 0);
// cutout.ctx.restore();
// delete the polygon from the canvas
// ctx.save();
// ctx.globalCompositeOperation = "destination-out"; // or something
// ctx.drawImage(cutout, 0, 0);
// ctx.restore();
var cutout_crop = new Canvas(width, height);
cutout_crop.ctx.drawImage(cutout, x_min, y_min, width, height, 0, 0, width, height);
return cutout_crop;
}
})();

3
src/tools.js
View File

@ -95,7 +95,8 @@ tools = [{
this.x_min,
this.y_min,
this.x_max,
this.y_max
this.y_max,
canvas
);
// Make the selection