summaryrefslogtreecommitdiff
path: root/progs/tests/stencilreaddraw.c
diff options
context:
space:
mode:
Diffstat (limited to 'progs/tests/stencilreaddraw.c')
-rw-r--r--progs/tests/stencilreaddraw.c187
1 files changed, 187 insertions, 0 deletions
diff --git a/progs/tests/stencilreaddraw.c b/progs/tests/stencilreaddraw.c
new file mode 100644
index 0000000000..84a5a922a0
--- /dev/null
+++ b/progs/tests/stencilreaddraw.c
@@ -0,0 +1,187 @@
+/*
+ * Test glRead/DrawPixels for GL_STENCIL_INDEX, with pixelzoom.
+ *
+ * Brian Paul
+ * 8 April 2010
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/glew.h>
+#include <GL/glut.h>
+
+static GLint WinWidth = 500, WinHeight = 500;
+static GLboolean TestPacking = GL_FALSE;
+static GLboolean TestList = GL_FALSE;
+
+
+static GLuint StencilValue = 192;
+
+static void Display(void)
+{
+ GLubyte stencil[100 * 100 * 2];
+ GLubyte stencil2[400 * 400]; /* *2 to test pixelstore stuff */
+ GLuint list;
+
+ glClearColor(0.5, 0.5, 0.5, 1.0);
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+
+ glEnable(GL_DEPTH_TEST);
+
+ glStencilOp(GL_INVERT, GL_KEEP, GL_REPLACE);
+ glStencilFunc(GL_ALWAYS, StencilValue, ~0);
+ glEnable(GL_STENCIL_TEST);
+
+ /* 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);
+
+ glDisable(GL_STENCIL_TEST);
+
+ if (TestPacking) {
+ glPixelStorei(GL_PACK_ROW_LENGTH, 120);
+ glPixelStorei(GL_PACK_SKIP_PIXELS, 5);
+ }
+
+ /* read the stencil image */
+ glReadPixels(0, 0, 100, 100, GL_STENCIL_INDEX, GL_UNSIGNED_BYTE, stencil);
+ {
+ GLubyte min, max;
+ int i;
+ min = max = stencil[0];
+ for (i = 1; i < 100 * 100; i++) {
+ if (stencil[i] < min)
+ min = stencil[i];
+ if (stencil[i] > max)
+ max = stencil[i];
+ }
+ printf("Stencil value range: [%u, %u]\n", min, max);
+ if (max != StencilValue) {
+ printf("Error: expected max stencil val of %u, found %u\n",
+ StencilValue, max);
+ }
+ }
+
+ /* Draw the Z image as luminance above original rendering */
+ glWindowPos2i(0, 100);
+ glDrawPixels(100, 100, GL_LUMINANCE, GL_UNSIGNED_BYTE, stencil);
+
+ if (1) {
+ if (TestPacking) {
+ glPixelStorei(GL_PACK_ROW_LENGTH, 0);
+ glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
+ glPixelStorei(GL_UNPACK_ROW_LENGTH, 120);
+ glPixelStorei(GL_UNPACK_SKIP_PIXELS, 5);
+ }
+
+ /* draw stencil image with scaling (into stencil buffer) */
+ glPixelZoom(4.0, 4.0);
+ glColor4f(1, 0, 0, 0);
+ glWindowPos2i(100, 0);
+
+ if (TestList) {
+ list = glGenLists(1);
+ glNewList(list, GL_COMPILE);
+ glDrawPixels(100, 100, GL_STENCIL_INDEX, GL_UNSIGNED_BYTE, stencil);
+ glEndList();
+ glCallList(list);
+ glDeleteLists(list, 1);
+ }
+ else {
+ glDrawPixels(100, 100, GL_STENCIL_INDEX, GL_UNSIGNED_BYTE, stencil);
+ }
+
+ if (TestPacking) {
+ glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
+ glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
+ }
+
+ /* read back scaled stencil image */
+ glReadPixels(100, 0, 400, 400, GL_STENCIL_INDEX,
+ GL_UNSIGNED_BYTE, stencil2);
+ /* draw as luminance */
+ glPixelZoom(1.0, 1.0);
+ glWindowPos2i(100, 0);
+ glDrawPixels(400, 400, GL_LUMINANCE, GL_UNSIGNED_BYTE, stencil2);
+ }
+
+ 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 'p':
+ TestPacking = !TestPacking;
+ printf("Test pixel pack/unpack: %d\n", TestPacking);
+ break;
+ case 'l':
+ TestList = !TestList;
+ printf("Test dlist: %d\n", TestList);
+ break;
+ case 27:
+ exit(0);
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static void Init(void)
+{
+ const GLfloat blue[4] = {.1, .1, 1.0, 1.0};
+ 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};
+ GLint bits;
+
+ printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
+ printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
+
+ glGetIntegerv(GL_STENCIL_BITS, &bits);
+ printf("Stencil bits: %d\n", bits);
+
+ assert(bits >= 8);
+
+ 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);
+}
+
+
+int main(int argc, char *argv[])
+{
+ glutInit(&argc, argv);
+ glutInitWindowPosition(0, 0);
+ glutInitWindowSize(WinWidth, WinHeight);
+ glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_STENCIL | GLUT_DOUBLE);
+ glutCreateWindow(argv[0]);
+ glewInit();
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(Key);
+ glutDisplayFunc(Display);
+ Init();
+ glutMainLoop();
+ return 0;
+}