progs/demos/osdemo.c

   1 /* $Id: osdemo.c,v 1.1 1999/08/19 00:55:40 jtg Exp $ */
   2
   3 /*
   4  * Demo of off-screen Mesa rendering
   5  *
   6  * See Mesa/include/GL/osmesa.h for documentation of the OSMesa functions.
   7  *
   8  * If you want to render BIG images you'll probably have to increase
   9  * MAX_WIDTH and MAX_HEIGHT in src/config.h.
  10  *
  11  * This program is in the public domain.
  12  *
  13  * Brian Paul
  14  *
  15  * PPM output provided by Joerg Schmalzl.
  16  * ASCII PPM output added by Brian Paul.
  17  */
  18
  19
  20 /*
  21  * $Log: osdemo.c,v $
  22  * Revision 1.1  1999/08/19 00:55:40  jtg
  23  * Initial revision
  24  *
  25  * Revision 3.0  1998/02/14 18:42:29  brianp
  26  * initial rev
  27  *
  28  */
  29
  30
  31
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include "GL/osmesa.h"
  35 #include "GL/glut.h"
  36
  37
  38
  39 #define WIDTH 400
  40 #define HEIGHT 400
  41
  42
  43
  44 static void render_image( void )
  45 {
  46    GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
  47    GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
  48    GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
  49    GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
  50    GLfloat red_mat[]   = { 1.0, 0.2, 0.2, 1.0 };
  51    GLfloat green_mat[] = { 0.2, 1.0, 0.2, 1.0 };
  52    GLfloat blue_mat[]  = { 0.2, 0.2, 1.0, 1.0 };
  53
  54
  55    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
  56    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
  57    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
  58    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  59
  60    glEnable(GL_LIGHTING);
  61    glEnable(GL_LIGHT0);
  62    glEnable(GL_DEPTH_TEST);
  63
  64    glMatrixMode(GL_PROJECTION);
  65    glLoadIdentity();
  66    glOrtho(-2.5, 2.5, -2.5, 2.5, -10.0, 10.0);
  67    glMatrixMode(GL_MODELVIEW);
  68
  69    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  70
  71    glPushMatrix();
  72    glRotatef(20.0, 1.0, 0.0, 0.0);
  73
  74    glPushMatrix();
  75    glTranslatef(-0.75, 0.5, 0.0);
  76    glRotatef(90.0, 1.0, 0.0, 0.0);
  77    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red_mat );
  78    glutSolidTorus(0.275, 0.85, 20, 20);
  79    glPopMatrix();
  80
  81    glPushMatrix();
  82    glTranslatef(-0.75, -0.5, 0.0);
  83    glRotatef(270.0, 1.0, 0.0, 0.0);
  84    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, green_mat );
  85    glutSolidCone(1.0, 2.0, 16, 1);
  86    glPopMatrix();
  87
  88    glPushMatrix();
  89    glTranslatef(0.75, 0.0, -1.0);
  90    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue_mat );
  91    glutSolidSphere(1.0, 20, 20);
  92    glPopMatrix();
  93
  94    glPopMatrix();
  95 }
  96
  97
  98
  99 int main( int argc, char *argv[] )
 100 {
 101    OSMesaContext ctx;
 102    void *buffer;
 103
 104    /* Create an RGBA-mode context */
 105    ctx = OSMesaCreateContext( GL_RGBA, NULL );
 106
 107    /* Allocate the image buffer */
 108    buffer = malloc( WIDTH * HEIGHT * 4 );
 109
 110    /* Bind the buffer to the context and make it current */
 111    OSMesaMakeCurrent( ctx, buffer, GL_UNSIGNED_BYTE, WIDTH, HEIGHT );
 112
 113    render_image();
 114
 115    if (argc>1) {
 116       /* write PPM file */
 117       FILE *f = fopen( argv[1], "w" );
 118       if (f) {
 119          int i, x, y;
 120          GLubyte *ptr = (GLubyte *) buffer;
 121 #define BINARY 0
 122 #if BINARY
 123          fprintf(f,"P6\n");
 124          fprintf(f,"# ppm-file created by %s\n",  argv[0]);
 125          fprintf(f,"%i %i\n", WIDTH,HEIGHT);
 126          fprintf(f,"255\n");
 127          fclose(f);
 128          f = fopen( argv[1], "ab" );  /* reopen in binary append mode */
 129          for (y=HEIGHT-1; y>=0; y--) {
 130             for (x=0; x<WIDTH; x++) {
 131                i = (y*WIDTH + x) * 4;
 132                fputc(ptr[i], f);   /* write red */
 133                fputc(ptr[i+1], f); /* write green */
 134                fputc(ptr[i+2], f); /* write blue */
 135             }
 136          }
 137 #else /*ASCII*/
 138          int counter = 0;
 139          fprintf(f,"P3\n");
 140          fprintf(f,"# ascii ppm file created by %s\n", argv[0]);
 141          fprintf(f,"%i %i\n", WIDTH, HEIGHT);
 142          fprintf(f,"255\n");
 143          for (y=HEIGHT-1; y>=0; y--) {
 144             for (x=0; x<WIDTH; x++) {
 145                i = (y*WIDTH + x) * 4;
 146                fprintf(f, " %3d %3d %3d", ptr[i], ptr[i+1], ptr[i+2]);
 147                counter++;
 148                if (counter % 5 == 0)
 149                   fprintf(f, "\n");
 150             }
 151          }
 152 #endif
 153          fclose(f);
 154       }
 155    }
 156    else {
 157       printf("Specify a filename if you want to make a ppm file\n");
 158    }
 159
 160    printf("all done\n");
 161
 162    /* free the image buffer */
 163    free( buffer );
 164
 165    /* destroy the context */
 166    OSMesaDestroyContext( ctx );
 167
 168    return 0;
 169 }