Add LASE demo source code

examples/CMakeLists.txt

@@ -42,3 +42,7 @@ add_executable(harp harp.c)
 target_link_libraries(harp openlase)
 
 add_subdirectory(27c3_slides)
+
+# Note: this target needs modplug but I'm too lazy to add a module finder for
+# it.
+#add_subdirectory(lase_demo)

examples/lase_demo/CMakeLists.txt

@@ -0,0 +1,6 @@
+include_directories (${CMAKE_SOURCE_DIR}/include)
+link_directories (${CMAKE_BINARY_DIR}/libol)
+
+add_executable(demo demo.c trace.c)
+target_link_libraries(demo openlase modplug)
+

examples/lase_demo/README

@@ -0,0 +1,17 @@
+Yes, this is the source code for LASE. Keep in mind that a good chunk of this
+was coded in a rush at the party, and it's also basically the first nontrivial
+code written for openlase. It has been modified slightly to make it work with
+the current API (which was slightly incompatible) but otherwise remains
+untouched, although it will look slightly better due to libol improvements
+since the demo was made.
+
+Danger: Here be dragons. :-)
+
+To compile: I've been too lazy to add a CMake module to conditionally search
+for libmodplug, so this is disabled by default. Uncomment the subdir at the end
+of ../CMakeLists.txt and make sure you have libmodplug and its headers (-dev
+package) installed.
+
+To run: make sure that GLOS-pope.xm is in your $PWD before running the binary
+(e.g. run it from this directory).
+

examples/lase_demo/trace.c

@@ -0,0 +1,123 @@
+#include "libol.h"
+#include <math.h>
+#include <string.h>
+
+#include "trace.h"
+
+#define ABS(a) ((a)<0?(-(a)):(a))
+
+#define OVERDRAW 8
+
+int trace(int *field, uint8_t *tmp, int thresh, int w, int h, int decimate)
+{
+	int x, y, cx, cy, px, py, i;
+	int iters = 0;
+	int objects = 0;
+
+	int sx[OVERDRAW], sy[OVERDRAW];
+
+	memset(tmp, 0, w*h);
+
+	for (y=1; y<h-1; y++) {
+		for (x=1; x<w-1;x++) {
+			int idx = y*w+x;
+			if (field[idx] > thresh && (!(field[idx-w] > thresh)
+			                         || !(field[idx+w] > thresh)
+			                         || !(field[idx-1] > thresh)
+			                         || !(field[idx+1] > thresh))) {
+				tmp[idx] = 1;
+			}
+		}
+	}
+
+	int total = h*w;
+	int dir = 0;
+	int minx = 0, miny = 0;
+	int maxx = w-1, maxy = h-1;
+
+	int div = 0;
+
+	px = 0;
+	py = 0;
+	while (total--)
+	{
+		if (tmp[py*w+px]) {
+			x = cx = px;
+			y = cy = py;
+			iters = 0;
+			olBegin(OL_POINTS);
+			while (1)
+			{
+				int idx = y*w+x;
+				if(div==0) {
+					if (iters < OVERDRAW) {
+						sx[iters] = x;
+						sy[iters] = y;
+					}
+					olVertex(x, y, C_WHITE);
+					iters++;
+				}
+				div = (div+1)%decimate;
+				tmp[idx] = 0;
+				if (tmp[idx-1]) {
+					x--;
+				} else if (tmp[idx+1]) {
+					x++;
+				} else if (tmp[idx-w]) {
+					y--;
+				} else if (tmp[idx+w]) {
+					y++;
+				} else if (tmp[idx-w-1]) {
+					y--; x--;
+				} else if (tmp[idx-w+1]) {
+					y--; x++;
+				} else if (tmp[idx+w-1]) {
+					y++; x--;
+				} else if (tmp[idx+w+1]) {
+					y++; x++;
+				} else {
+					break;
+				}
+
+			}
+			if (iters) {
+				objects++;
+				if (ABS(cx-x) <= 1 && ABS(cy-y) <= 1) {
+					if (iters > OVERDRAW)
+						iters = OVERDRAW;
+					for (i=0; i<iters; i++)
+						olVertex(sx[i], sy[i], C_GREY((int)(255.0 * (OVERDRAW - 1 - i) / (float)OVERDRAW)));
+				}
+			}
+			olEnd();
+		}
+		switch(dir) {
+			case 0:
+				px++;
+				if (px > maxx) {
+					px--; py++; maxx--; dir++;
+				}
+				break;
+			case 1:
+				py++;
+				if (py > maxy) {
+					py--; px--; maxy--; dir++;
+				}
+				break;
+			case 2:
+				px--;
+				if (px < minx) {
+					px++; py--; minx++; dir++;
+				}
+				break;
+			case 3:
+				py--;
+				if (py < miny) {
+					py++; px++; miny++; dir=0;
+				}
+				break;
+		}
+	}
+	return objects;
+}
+

examples/lase_demo/trace.h

@@ -0,0 +1,6 @@
+#ifndef TRACE_H
+#define TRACE_H
+
+int trace(int *field, uint8_t *tmp, int thresh, int width, int height, int decimate);
+
+#endif