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| -rw-r--r-- | progs/tests/stencilreaddraw.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/progs/tests/stencilreaddraw.c b/progs/tests/stencilreaddraw.c new file mode 100644 index 00000000000..84a5a922a0e --- /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; +} |