+++ /dev/null
-
-/*
- * This program demonstrates how to do "off-screen" rendering using
- * the GLX pixel buffer extension.
- *
- * Written by Brian Paul for the "OpenGL and Window System Integration"
- * course presented at SIGGRAPH '97. Updated on 5 October 2002.
- *
- * Updated on 31 January 2004 to use native GLX by
- * Andrew P. Lentvorski, Jr. <bsder@allcaps.org>
- *
- * Usage:
- * glxpbdemo width height imgfile
- * Where:
- * width is the width, in pixels, of the image to generate.
- * height is the height, in pixels, of the image to generate.
- * imgfile is the name of the PPM image file to write.
- *
- *
- * This demo draws 3-D boxes with random orientation.
- *
- * On machines such as the SGI Indigo you may have to reconfigure your
- * display/X server to enable pbuffers. Look in the /usr/gfx/ucode/MGRAS/vof/
- * directory for display configurations with the _pbuf suffix. Use
- * setmon -x <vof> to configure your X server and display for pbuffers.
- *
- * O2 systems seem to support pbuffers well.
- *
- */
-
-#include <string.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <X11/Xlib.h>
-#include <GL/glx.h>
-
-/* Some ugly global vars */
-static GLXFBConfig gFBconfig = 0;
-static Display *gDpy = NULL;
-static int gScreen = 0;
-static GLXPbuffer gPBuffer = 0;
-static int gWidth, gHeight;
-
-
-/*
- * Test for appropriate version of GLX to run this program
- * Input: dpy - the X display
- * screen - screen number
- * Return: 0 = GLX not available.
- * 1 = GLX available.
- */
-static int
-RuntimeQueryGLXVersion(Display *dpy, int screen)
-{
-#if defined(GLX_VERSION_1_3) || defined(GLX_VERSION_1_4)
- char *glxversion;
-
- glxversion = (char *) glXGetClientString(dpy, GLX_VERSION);
- if (!(strstr(glxversion, "1.3") || strstr(glxversion, "1.4")))
- return 0;
-
- glxversion = (char *) glXQueryServerString(dpy, screen, GLX_VERSION);
- if (!(strstr(glxversion, "1.3") || strstr(glxversion, "1.4")))
- return 0;
-
- return 1;
-#else
- return 0;
-#endif
-}
-
-
-
-/*
- * Create the pbuffer and return a GLXPbuffer handle.
- */
-static GLXPbuffer
-MakePbuffer( Display *dpy, int screen, int width, int height )
-{
- GLXFBConfig *fbConfigs;
- GLXFBConfig chosenFBConfig;
- GLXPbuffer pBuffer = None;
-
- int nConfigs;
- int fbconfigid;
-
- int fbAttribs[] = {
- GLX_RENDER_TYPE, GLX_RGBA_BIT,
- GLX_DEPTH_SIZE, 1,
- GLX_DRAWABLE_TYPE, GLX_PIXMAP_BIT | GLX_PBUFFER_BIT,
- None
- };
-
- int pbAttribs[] = {
- GLX_PBUFFER_WIDTH, 0,
- GLX_PBUFFER_HEIGHT, 0,
- GLX_LARGEST_PBUFFER, False,
- GLX_PRESERVED_CONTENTS, False,
- None
- };
-
- pbAttribs[1] = width;
- pbAttribs[3] = height;
-
- fbConfigs = glXChooseFBConfig(dpy, screen, fbAttribs, &nConfigs);
-
- if (0 == nConfigs || !fbConfigs) {
- printf("Error: glxChooseFBConfig failed\n");
- XFree(fbConfigs);
- XCloseDisplay(dpy);
- return 0;
- }
-
- chosenFBConfig = fbConfigs[0];
-
- glXGetFBConfigAttrib(dpy, chosenFBConfig, GLX_FBCONFIG_ID, &fbconfigid);
- printf("Chose 0x%x as fbconfigid\n", fbconfigid);
-
- /* Create the pbuffer using first fbConfig in the list that works. */
- pBuffer = glXCreatePbuffer(dpy, chosenFBConfig, pbAttribs);
-
- if (pBuffer) {
- gFBconfig = chosenFBConfig;
- gWidth = width;
- gHeight = height;
- }
-
- XFree(fbConfigs);
-
- return pBuffer;
-}
-
-
-
-/*
- * Do all the X / GLX setup stuff.
- */
-static int
-Setup(int width, int height)
-{
-#if defined(GLX_VERSION_1_3) || defined(GLX_VERSION_1_4)
- GLXContext glCtx;
-
- /* Open the X display */
- gDpy = XOpenDisplay(NULL);
- if (!gDpy) {
- printf("Error: couldn't open default X display.\n");
- return 0;
- }
-
- /* Get default screen */
- gScreen = DefaultScreen(gDpy);
-
- /* Test that GLX is available */
- if (!RuntimeQueryGLXVersion(gDpy, gScreen)) {
- printf("Error: GLX 1.3 or 1.4 not available\n");
- XCloseDisplay(gDpy);
- return 0;
- }
-
- /* Create Pbuffer */
- gPBuffer = MakePbuffer( gDpy, gScreen, width, height );
- if (gPBuffer==None) {
- printf("Error: couldn't create pbuffer\n");
- XCloseDisplay(gDpy);
- return 0;
- }
-
- /* Create GLX context */
- glCtx = glXCreateNewContext(gDpy, gFBconfig, GLX_RGBA_TYPE, NULL, True);
- if (glCtx) {
- if (!glXIsDirect(gDpy, glCtx)) {
- printf("Warning: using indirect GLXContext\n");
- }
- }
- else {
- printf("Error: Couldn't create GLXContext\n");
- XCloseDisplay(gDpy);
- return 0;
- }
-
- /* Bind context to pbuffer */
- if (!glXMakeCurrent(gDpy, gPBuffer, glCtx)) {
- printf("Error: glXMakeCurrent failed\n");
- XCloseDisplay(gDpy);
- return 0;
- }
-
- return 1; /* Success!! */
-#else
- printf("Error: GLX version 1.3 or 1.4 not available at compile time\n");
- return 0;
-#endif
-}
-
-
-
-/* One-time GL setup */
-static void
-InitGL(void)
-{
- static GLfloat pos[4] = {0.0, 0.0, 10.0, 0.0};
- glEnable(GL_LIGHTING);
- glEnable(GL_LIGHT0);
- glLightfv(GL_LIGHT0, GL_POSITION, pos);
- glEnable(GL_NORMALIZE);
- glEnable(GL_DEPTH_TEST);
- glEnable(GL_CULL_FACE);
-
- glViewport(0, 0, gWidth, gHeight);
- glMatrixMode( GL_PROJECTION );
- glLoadIdentity();
- glFrustum( -1.0, 1.0, -1.0, 1.0, 5.0, 25.0 );
- glMatrixMode( GL_MODELVIEW );
- glLoadIdentity();
- glTranslatef( 0.0, 0.0, -15.0 );
-
-}
-
-
-/* Return random float in [0,1] */
-static float
-Random(void)
-{
- int i = rand();
- return (float) (i % 1000) / 1000.0;
-}
-
-
-static void
-RandomColor(void)
-{
- GLfloat c[4];
- c[0] = Random();
- c[1] = Random();
- c[2] = Random();
- c[3] = 1.0;
- glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, c);
-}
-
-
-/* This function borrowed from Mark Kilgard's GLUT */
-static void
-drawBox(GLfloat x0, GLfloat x1, GLfloat y0, GLfloat y1,
- GLfloat z0, GLfloat z1, GLenum type)
-{
- static GLfloat n[6][3] =
- {
- {-1.0, 0.0, 0.0},
- {0.0, 1.0, 0.0},
- {1.0, 0.0, 0.0},
- {0.0, -1.0, 0.0},
- {0.0, 0.0, 1.0},
- {0.0, 0.0, -1.0}
- };
- static GLint faces[6][4] =
- {
- {0, 1, 2, 3},
- {3, 2, 6, 7},
- {7, 6, 5, 4},
- {4, 5, 1, 0},
- {5, 6, 2, 1},
- {7, 4, 0, 3}
- };
- GLfloat v[8][3], tmp;
- GLint i;
-
- if (x0 > x1) {
- tmp = x0;
- x0 = x1;
- x1 = tmp;
- }
- if (y0 > y1) {
- tmp = y0;
- y0 = y1;
- y1 = tmp;
- }
- if (z0 > z1) {
- tmp = z0;
- z0 = z1;
- z1 = tmp;
- }
- v[0][0] = v[1][0] = v[2][0] = v[3][0] = x0;
- v[4][0] = v[5][0] = v[6][0] = v[7][0] = x1;
- v[0][1] = v[1][1] = v[4][1] = v[5][1] = y0;
- v[2][1] = v[3][1] = v[6][1] = v[7][1] = y1;
- v[0][2] = v[3][2] = v[4][2] = v[7][2] = z0;
- v[1][2] = v[2][2] = v[5][2] = v[6][2] = z1;
-
- for (i = 0; i < 6; i++) {
- glBegin(type);
- glNormal3fv(&n[i][0]);
- glVertex3fv(&v[faces[i][0]][0]);
- glVertex3fv(&v[faces[i][1]][0]);
- glVertex3fv(&v[faces[i][2]][0]);
- glVertex3fv(&v[faces[i][3]][0]);
- glEnd();
- }
-}
-
-
-
-/* Render a scene */
-static void
-Render(void)
-{
- int NumBoxes = 100;
- int i;
-
- InitGL();
- glClearColor(0.2, 0.2, 0.9, 0.0);
- glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-
- for (i=0;i<NumBoxes;i++) {
- float tx = -2.0 + 4.0 * Random();
- float ty = -2.0 + 4.0 * Random();
- float tz = 4.0 - 16.0 * Random();
- float sx = 0.1 + Random() * 0.4;
- float sy = 0.1 + Random() * 0.4;
- float sz = 0.1 + Random() * 0.4;
- float rx = Random();
- float ry = Random();
- float rz = Random();
- float ra = Random() * 360.0;
- glPushMatrix();
- glTranslatef(tx, ty, tz);
- glRotatef(ra, rx, ry, rz);
- glScalef(sx, sy, sz);
- RandomColor();
- drawBox(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0, GL_POLYGON);
- glPopMatrix();
- }
-
- glFinish();
-}
-
-
-
-static void
-WriteFile(const char *filename)
-{
- FILE *f;
- GLubyte *image;
- int i;
-
- image = malloc(gWidth * gHeight * 3 * sizeof(GLubyte));
- if (!image) {
- printf("Error: couldn't allocate image buffer\n");
- return;
- }
-
- glPixelStorei(GL_PACK_ALIGNMENT, 1);
- glReadPixels(0, 0, gWidth, gHeight, GL_RGB, GL_UNSIGNED_BYTE, image);
-
- f = fopen(filename, "w");
- if (!f) {
- printf("Couldn't open image file: %s\n", filename);
- return;
- }
- fprintf(f,"P6\n");
- fprintf(f,"# ppm-file created by %s\n", "trdemo2");
- fprintf(f,"%i %i\n", gWidth, gHeight);
- fprintf(f,"255\n");
- fclose(f);
- f = fopen(filename, "ab"); /* now append binary data */
- if (!f) {
- printf("Couldn't append to image file: %s\n", filename);
- return;
- }
-
- for (i=0;i<gHeight;i++) {
- GLubyte *rowPtr;
- /* Remember, OpenGL images are bottom to top. Have to reverse. */
- rowPtr = image + (gHeight-1-i) * gWidth*3;
- fwrite(rowPtr, 1, gWidth*3, f);
- }
-
- fclose(f);
- free(image);
-
- printf("Wrote %d by %d image file: %s\n", gWidth, gHeight, filename);
-}
-
-
-
-/*
- * Print message describing command line parameters.
- */
-static void
-Usage(const char *appName)
-{
- printf("Usage:\n");
- printf(" %s width height imgfile\n", appName);
- printf("Where imgfile is a ppm file\n");
-}
-
-
-
-int
-main(int argc, char *argv[])
-{
- if (argc!=4) {
- Usage(argv[0]);
- }
- else {
- int width = atoi(argv[1]);
- int height = atoi(argv[2]);
- char *fileName = argv[3];
- if (width<=0) {
- printf("Error: width parameter must be at least 1.\n");
- return 1;
- }
- if (height<=0) {
- printf("Error: height parameter must be at least 1.\n");
- return 1;
- }
- if (!Setup(width, height)) {
- return 1;
- }
-
- printf("Setup completed\n");
- Render();
- printf("Render completed.\n");
- WriteFile(fileName);
- printf("File write completed.\n");
-
- glXDestroyPbuffer( gDpy, gPBuffer );
- }
- return 0;
-}
-