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-rw-r--r--progs/tests/zdrawpix.c192
1 files changed, 192 insertions, 0 deletions
diff --git a/progs/tests/zdrawpix.c b/progs/tests/zdrawpix.c
new file mode 100644
index 0000000000..dd222e7dd0
--- /dev/null
+++ b/progs/tests/zdrawpix.c
@@ -0,0 +1,192 @@
+/**
+ * Test glDrawPixels(GL_DEPTH_COMPONENT)
+ *
+ * We load a window-sized buffer of Z values so that Z=1 at the top and
+ * Z=0 at the bottom (and interpolate between).
+ * We draw that image into the Z buffer, then draw an ordinary cube.
+ * The bottom part of the cube should be "clipped" where the cube fails
+ * the Z test.
+ *
+ * Press 'd' to view the Z buffer as a grayscale image.
+ */
+
+#define GL_GLEXT_PROTOTYPES
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/glut.h>
+#include "../util/showbuffer.c"
+
+
+static int Win;
+static GLfloat Xrot = 50, Yrot = 40, Zpos = 6;
+static GLboolean Anim = GL_FALSE;
+
+static int Width = 200, Height = 200;
+static GLfloat *z;
+static GLboolean showZ = 0;
+
+
+static void
+Idle(void)
+{
+ Xrot += 3.0;
+ Yrot += 4.0;
+ glutPostRedisplay();
+}
+
+
+static void
+Draw(void)
+{
+ glClearColor(0, 0, 0.5, 0);
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+#if 1
+ glColor3f(1, 0, 0);
+ glWindowPos2i(0,0);
+ glColorMask(0,0,0,0);
+ glDrawPixels(Width, Height, GL_DEPTH_COMPONENT, GL_FLOAT, z);
+#elif 0
+ glPushMatrix();
+ glTranslatef(-0.75, 0, Zpos);
+ glutSolidSphere(1.0, 20, 10);
+ glPopMatrix();
+#endif
+ glColorMask(1,1,1,1);
+
+ /* draw cube */
+ glPushMatrix();
+ glTranslatef(0, 0, Zpos);
+ glRotatef(Xrot, 1, 0, 0);
+ glRotatef(Yrot, 0, 1, 0);
+ glutSolidCube(2.0);
+ glPopMatrix();
+
+#if 0
+ /* drawpixels after cube */
+ glColor3f(1, 0, 0);
+ glWindowPos2i(0,0);
+ //glColorMask(0,0,0,0);
+ glDrawPixels(Width, Height, GL_DEPTH_COMPONENT, GL_FLOAT, z);
+#endif
+
+ if (showZ) {
+ ShowDepthBuffer(Width, Height, 0.0, 1.0);
+ }
+
+ glutSwapBuffers();
+}
+
+
+static void
+Reshape(int width, int height)
+{
+ glViewport(0, 0, width, height);
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 30.0);
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+ glTranslatef(0.0, 0.0, -15.0);
+
+ Width = width;
+ Height = height;
+
+ z = (float *) malloc(width * height * 4);
+ {
+ int i, j, k = 0;
+ for (i = 0; i < height; i++) {
+ float zval = (float) i / (height - 1);
+ for (j = 0; j < width; j++) {
+ z[k++] = zval;
+ }
+ }
+ }
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+ const GLfloat step = 1.0;
+ (void) x;
+ (void) y;
+ switch (key) {
+ case 'a':
+ Anim = !Anim;
+ if (Anim)
+ glutIdleFunc(Idle);
+ else
+ glutIdleFunc(NULL);
+ break;
+ case 'd':
+ showZ = !showZ;
+ break;
+ case 'z':
+ Zpos -= step;
+ break;
+ case 'Z':
+ Zpos += step;
+ break;
+ case 27:
+ glutDestroyWindow(Win);
+ exit(0);
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static void
+SpecialKey(int key, int x, int y)
+{
+ const GLfloat step = 3.0;
+ (void) x;
+ (void) y;
+ switch (key) {
+ case GLUT_KEY_UP:
+ Xrot -= step;
+ break;
+ case GLUT_KEY_DOWN:
+ Xrot += step;
+ break;
+ case GLUT_KEY_LEFT:
+ Yrot -= step;
+ break;
+ case GLUT_KEY_RIGHT:
+ Yrot += step;
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static void
+Init(void)
+{
+ /* setup lighting, etc */
+ glEnable(GL_DEPTH_TEST);
+ glEnable(GL_LIGHTING);
+ glEnable(GL_LIGHT0);
+}
+
+
+int
+main(int argc, char *argv[])
+{
+ glutInit(&argc, argv);
+ glutInitWindowPosition(0, 0);
+ glutInitWindowSize(400, 400);
+ glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
+ Win = glutCreateWindow(argv[0]);
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(Key);
+ glutSpecialFunc(SpecialKey);
+ glutDisplayFunc(Draw);
+ if (Anim)
+ glutIdleFunc(Idle);
+ Init();
+ glutMainLoop();
+ return 0;
+}