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authorBrian Paul <brian.paul@tungstengraphics.com>2003-08-23 21:42:57 +0000
committerBrian Paul <brian.paul@tungstengraphics.com>2003-08-23 21:42:57 +0000
commit2230b8518ea98df5e8039c2d5d4976e6f4fc850f (patch)
tree59525abecb8bb60ae4e84394c425cc1079484cfe /progs/tests
parent4be6c0f04b9ba81dba144b45f92ab807e141755f (diff)
test program to exercise glDraw/ReadPixels(GL_DEPTH_COMPONENT) and pixel zooming
Diffstat (limited to 'progs/tests')
-rw-r--r--progs/tests/zreaddraw.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/progs/tests/zreaddraw.c b/progs/tests/zreaddraw.c
new file mode 100644
index 0000000000..e2dacbf7f2
--- /dev/null
+++ b/progs/tests/zreaddraw.c
@@ -0,0 +1,116 @@
+/*
+ * Test glRead/DrawPixels for GL_DEPTH_COMPONENT, with pixelzoom.
+ *
+ * Brian Paul
+ * 23 August 2003
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#define GL_GLEXT_PROTOTYPES
+#include <GL/glut.h>
+
+static GLint WinWidth = 500, WinHeight = 500;
+
+
+static void Display(void)
+{
+ GLfloat depth[100 * 100];
+ GLfloat depth2[400 * 400];
+ GLfloat min, max;
+ int i;
+
+ glClearColor(0.5, 0.5, 0.5, 0);
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+ /* draw a sphere */
+ glViewport(0, 0, 100, 100);
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glOrtho(-1, 1, -1, 1, -1, 0); /* clip away back half of sphere */
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+ glutSolidSphere(1.0, 20, 10);
+
+ /* read the depth image */
+ glReadPixels(0, 0, 100, 100, GL_DEPTH_COMPONENT, GL_FLOAT, depth);
+ min = max = depth[0];
+ for (i = 1; i < 100 * 100; i++) {
+ if (depth[i] < min)
+ min = depth[i];
+ if (depth[i] > max)
+ max = depth[i];
+ }
+ printf("Depth value range: [%f, %f]\n", min, max);
+
+ /* draw depth image with scaling (into z buffer) */
+ glPixelZoom(4.0, 4.0);
+ glWindowPos2i(100, 0);
+ glDrawPixels(100, 100, GL_DEPTH_COMPONENT, GL_FLOAT, depth);
+
+ /* read back scaled depth image */
+ glReadPixels(100, 0, 400, 400, GL_DEPTH_COMPONENT, GL_FLOAT, depth2);
+ /* draw as luminance */
+ glPixelZoom(1.0, 1.0);
+ glDrawPixels(400, 400, GL_LUMINANCE, GL_FLOAT, depth2);
+
+ glutSwapBuffers();
+}
+
+
+static void Reshape(int width, int height)
+{
+ WinWidth = width;
+ WinHeight = height;
+ glViewport(0, 0, width, height);
+}
+
+
+static void Key(unsigned char key, int x, int y)
+{
+ (void) x;
+ (void) y;
+ switch (key) {
+ case 27:
+ exit(0);
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static void Init(void)
+{
+ const GLfloat blue[4] = {.1, .1, 1.0, 0.0};
+ const GLfloat gray[4] = {0.2, 0.2, 0.2, 1.0};
+ const GLfloat white[4] = {1.0, 1.0, 1.0, 1.0};
+ const GLfloat pos[4] = {0, 0, 10, 0};
+
+ printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
+ printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
+
+ glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, blue);
+ glLightfv(GL_LIGHT0, GL_AMBIENT, gray);
+ glLightfv(GL_LIGHT0, GL_DIFFUSE, white);
+ glLightfv(GL_LIGHT0, GL_POSITION, pos);
+ glEnable(GL_LIGHTING);
+ glEnable(GL_LIGHT0);
+ glEnable(GL_DEPTH_TEST);
+}
+
+
+int main(int argc, char *argv[])
+{
+ glutInit(&argc, argv);
+ glutInitWindowPosition(0, 0);
+ glutInitWindowSize(WinWidth, WinHeight);
+ glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
+ glutCreateWindow(argv[0]);
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(Key);
+ glutDisplayFunc(Display);
+ Init();
+ glutMainLoop();
+ return 0;
+}