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-rw-r--r--progs/demos/dissolve.c137
1 files changed, 131 insertions, 6 deletions
diff --git a/progs/demos/dissolve.c b/progs/demos/dissolve.c
index 0b8df1bb669..8ab5242d91c 100644
--- a/progs/demos/dissolve.c
+++ b/progs/demos/dissolve.c
@@ -1,5 +1,5 @@
/**
- * Dissolve between two images using randomized stencil buffer
+ * Dissolve between two images using randomized/patterned stencil buffer
* and varying stencil ref.
*
* Brian Paul
@@ -9,6 +9,7 @@
#include <stdio.h>
#include <stdlib.h>
+#include <string.h>
#include <math.h>
#include <GL/glut.h>
#include "readtex.h"
@@ -28,6 +29,8 @@ static GLfloat ScaleX[2], ScaleY[2];
static GLubyte StencilRef = 0;
+static int Mode = 0;
+
static void
Idle(void)
@@ -38,13 +41,114 @@ Idle(void)
static void
-RandomizeStencilBuffer(void)
+FillRandomPixels(GLubyte *b)
{
- GLubyte *b = malloc(WinWidth * WinHeight);
int i;
for (i = 0; i < WinWidth * WinHeight; i++) {
b[i] = rand() & 0xff;
}
+}
+
+
+static void
+FillRandomRects(GLubyte *b)
+{
+ int i;
+
+ memset(b, 0, WinWidth * WinHeight);
+
+ for (i = 0; i < 256; i++) {
+ int x = rand() % WinWidth;
+ int y = rand() % WinHeight;
+ int w = rand() % 60;
+ int h = rand() % 60;
+ int ix, iy;
+
+ if (x + w > WinWidth)
+ w = WinWidth - x;
+ if (y + h > WinHeight)
+ h = WinHeight - y;
+
+ for (iy = 0; iy < h; iy++) {
+ for (ix = 0; ix < w; ix++) {
+ int p = (y + iy) * WinWidth + x + ix;
+ b[p] = i;
+ }
+ }
+ }
+}
+
+
+static void
+FillWipe(GLubyte *b)
+{
+ int iy, ix;
+
+ memset(b, 0, WinWidth * WinHeight);
+
+ for (iy = 0; iy < WinHeight; iy++) {
+ for (ix = 0; ix < WinWidth; ix++) {
+ int p = iy * WinWidth + ix;
+ b[p] = 2 * ix + iy / 2;
+ }
+ }
+}
+
+
+static void
+FillMoire(GLubyte *b)
+{
+ int iy, ix;
+
+ memset(b, 0, WinWidth * WinHeight);
+
+ for (iy = 0; iy < WinHeight; iy++) {
+ for (ix = 0; ix < WinWidth; ix++) {
+ int p = iy * WinWidth + ix;
+ b[p] = (ix / 2) * (ix / 2) - (iy / 2) * (iy / 2);
+ }
+ }
+}
+
+
+static void
+FillWaves(GLubyte *b)
+{
+ int iy, ix;
+
+ memset(b, 0, WinWidth * WinHeight);
+
+ for (iy = 0; iy < WinHeight; iy++) {
+ for (ix = 0; ix < WinWidth; ix++) {
+ int p = iy * WinWidth + ix;
+ float x = 8.0 * 3.1415 * ix / (float) WinWidth;
+ b[p] = (int) (25.0 * sin(x) ) - iy*2;
+ }
+ }
+}
+
+
+typedef void (*FillFunc)(GLubyte *b);
+
+
+static FillFunc Funcs[] = {
+ FillRandomPixels,
+ FillRandomRects,
+ FillWipe,
+ FillMoire,
+ FillWaves
+};
+
+#define NUM_MODES (sizeof(Funcs) / sizeof(Funcs[0]))
+
+
+
+static void
+InitStencilBuffer(void)
+{
+ GLubyte *b = malloc(WinWidth * WinHeight);
+
+ Funcs[Mode](b);
glStencilFunc(GL_ALWAYS, 0, ~0);
glPixelZoom(1.0, 1.0);
@@ -54,7 +158,6 @@ RandomizeStencilBuffer(void)
}
-
static void
Draw(void)
{
@@ -85,7 +188,7 @@ Reshape(int width, int height)
glLoadIdentity();
glTranslatef(0.0, 0.0, -15.0);
- RandomizeStencilBuffer();
+ InitStencilBuffer();
ScaleX[0] = (float) width / ImgWidth[0];
ScaleY[0] = (float) height / ImgHeight[0];
@@ -102,12 +205,26 @@ Key(unsigned char key, int x, int y)
(void) y;
switch (key) {
case 'a':
+ case ' ':
Anim = !Anim;
if (Anim)
glutIdleFunc(Idle);
else
glutIdleFunc(NULL);
break;
+ case 'i':
+ InitStencilBuffer();
+ break;
+ case '-':
+ StencilRef--;
+ break;
+ case '+':
+ StencilRef++;
+ break;
+ case 'm':
+ Mode = (Mode + 1) % NUM_MODES;
+ InitStencilBuffer();
+ break;
case 27:
glutDestroyWindow(Win);
exit(0);
@@ -143,8 +260,8 @@ Init(void)
int
main(int argc, char *argv[])
{
- glutInit(&argc, argv);
glutInitWindowSize(WinWidth, WinHeight);
+ glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH | GLUT_STENCIL);
Win = glutCreateWindow(argv[0]);
glutReshapeFunc(Reshape);
@@ -153,6 +270,14 @@ main(int argc, char *argv[])
if (Anim)
glutIdleFunc(Idle);
Init();
+
+ printf("Keys:\n");
+ printf(" a/SPACE toggle animation\n");
+ printf(" +/- single step\n");
+ printf(" i re-init pattern\n");
+ printf(" m change pattern/dissolve mode\n");
+ printf(" ESC exit\n");
+
glutMainLoop();
return 0;
}