progs/osdemos/osdemo.c

   1
   2 /*
   3  * Demo of off-screen Mesa rendering
   4  *
   5  * See Mesa/include/GL/osmesa.h for documentation of the OSMesa functions.
   6  *
   7  * If you want to render BIG images you'll probably have to increase
   8  * MAX_WIDTH and MAX_HEIGHT in src/config.h.
   9  *
  10  * This program is in the public domain.
  11  *
  12  * Brian Paul
  13  *
  14  * PPM output provided by Joerg Schmalzl.
  15  * ASCII PPM output added by Brian Paul.
  16  *
  17  * Usage: osdemo [-perf] [filename]
  18  *
  19  * -perf: Redraws the image 1000 times, displaying the FPS every 5 secs.
  20  * filename: file to store the TGA or PPM output
  21  */
  22
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include "GL/osmesa.h"
  28 #include "GL/glut.h"
  29
  30
  31 #define SAVE_TARGA
  32
  33
  34 #define WIDTH 400
  35 #define HEIGHT 400
  36
  37 static GLint T0 = 0;
  38 static GLint Frames = 0;
  39 static int perf = 0;
  40
  41 static void render_image( void )
  42 {
  43    GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
  44    GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
  45    GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
  46    GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
  47    GLfloat red_mat[]   = { 1.0, 0.2, 0.2, 1.0 };
  48    GLfloat green_mat[] = { 0.2, 1.0, 0.2, 1.0 };
  49    GLfloat blue_mat[]  = { 0.2, 0.2, 1.0, 1.0 };
  50
  51
  52    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
  53    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
  54    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
  55    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  56
  57    glEnable(GL_LIGHTING);
  58    glEnable(GL_LIGHT0);
  59    glEnable(GL_DEPTH_TEST);
  60
  61    glMatrixMode(GL_PROJECTION);
  62    glLoadIdentity();
  63    glOrtho(-2.5, 2.5, -2.5, 2.5, -10.0, 10.0);
  64    glMatrixMode(GL_MODELVIEW);
  65
  66    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  67
  68    glPushMatrix();
  69    glRotatef(20.0, 1.0, 0.0, 0.0);
  70
  71    glPushMatrix();
  72    glTranslatef(-0.75, 0.5, 0.0);
  73    glRotatef(90.0, 1.0, 0.0, 0.0);
  74    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red_mat );
  75    glutSolidTorus(0.275, 0.85, 20, 20);
  76    glPopMatrix();
  77
  78    glPushMatrix();
  79    glTranslatef(-0.75, -0.5, 0.0);
  80    glRotatef(270.0, 1.0, 0.0, 0.0);
  81    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, green_mat );
  82    glutSolidCone(1.0, 2.0, 16, 1);
  83    glPopMatrix();
  84
  85    glPushMatrix();
  86    glTranslatef(0.75, 0.0, -1.0);
  87    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue_mat );
  88    glutSolidSphere(1.0, 20, 20);
  89    glPopMatrix();
  90
  91    glPopMatrix();
  92
  93    /* This is very important!!!
  94     * Make sure buffered commands are finished!!!
  95     */
  96    glFinish();
  97
  98    Frames++;
  99    if (perf) {
 100      GLint t = glutGet(GLUT_ELAPSED_TIME);
 101      if (t - T0 >= 5000) {
 102         GLfloat seconds = (t - T0) / 1000.0;
 103         GLfloat fps = Frames / seconds;
 104         printf("%d frames in %6.3f seconds = %6.3f FPS\n", Frames, seconds, fps);
 105         T0 = t;
 106         Frames = 0;
 107      }
 108    }
 109 }
 110
 111
 112 #ifdef SAVE_TARGA
 113
 114 static void
 115 write_targa(const char *filename, const GLubyte *buffer, int width, int height)
 116 {
 117    FILE *f = fopen( filename, "w" );
 118    if (f) {
 119       int i, x, y;
 120       const GLubyte *ptr = buffer;
 121       printf ("osdemo, writing tga file \n");
 122       fputc (0x00, f);  /* ID Length, 0 => No ID        */
 123       fputc (0x00, f);  /* Color Map Type, 0 => No color map included   */
 124       fputc (0x02, f);  /* Image Type, 2 => Uncompressed, True-color Image */
 125       fputc (0x00, f);  /* Next five bytes are about the color map entries */
 126       fputc (0x00, f);  /* 2 bytes Index, 2 bytes length, 1 byte size */
 127       fputc (0x00, f);
 128       fputc (0x00, f);
 129       fputc (0x00, f);
 130       fputc (0x00, f);  /* X-origin of Image    */
 131       fputc (0x00, f);
 132       fputc (0x00, f);  /* Y-origin of Image    */
 133       fputc (0x00, f);
 134       fputc (WIDTH & 0xff, f);      /* Image Width      */
 135       fputc ((WIDTH>>8) & 0xff, f);
 136       fputc (HEIGHT & 0xff, f);     /* Image Height     */
 137       fputc ((HEIGHT>>8) & 0xff, f);
 138       fputc (0x18, f);          /* Pixel Depth, 0x18 => 24 Bits */
 139       fputc (0x20, f);          /* Image Descriptor     */
 140       fclose(f);
 141       f = fopen( filename, "ab" );  /* reopen in binary append mode */
 142       for (y=height-1; y>=0; y--) {
 143          for (x=0; x<width; x++) {
 144             i = (y*width + x) * 4;
 145             fputc(ptr[i+2], f); /* write blue */
 146             fputc(ptr[i+1], f); /* write green */
 147             fputc(ptr[i], f);   /* write red */
 148          }
 149       }
 150    }
 151 }
 152
 153 #else
 154
 155 static void
 156 write_ppm(const char *filename, const GLubyte *buffer, int width, int height)
 157 {
 158    const int binary = 0;
 159    FILE *f = fopen( filename, "w" );
 160    if (f) {
 161       int i, x, y;
 162       const GLubyte *ptr = buffer;
 163       if (binary) {
 164          fprintf(f,"P6\n");
 165          fprintf(f,"# ppm-file created by osdemo.c\n");
 166          fprintf(f,"%i %i\n", width,height);
 167          fprintf(f,"255\n");
 168          fclose(f);
 169          f = fopen( filename, "ab" );  /* reopen in binary append mode */
 170          for (y=height-1; y>=0; y--) {
 171             for (x=0; x<width; x++) {
 172                i = (y*width + x) * 4;
 173                fputc(ptr[i], f);   /* write red */
 174                fputc(ptr[i+1], f); /* write green */
 175                fputc(ptr[i+2], f); /* write blue */
 176             }
 177          }
 178       }
 179       else {
 180          /*ASCII*/
 181          int counter = 0;
 182          fprintf(f,"P3\n");
 183          fprintf(f,"# ascii ppm file created by osdemo.c\n");
 184          fprintf(f,"%i %i\n", width, height);
 185          fprintf(f,"255\n");
 186          for (y=height-1; y>=0; y--) {
 187             for (x=0; x<width; x++) {
 188                i = (y*width + x) * 4;
 189                fprintf(f, " %3d %3d %3d", ptr[i], ptr[i+1], ptr[i+2]);
 190                counter++;
 191                if (counter % 5 == 0)
 192                   fprintf(f, "\n");
 193             }
 194          }
 195       }
 196       fclose(f);
 197    }
 198 }
 199
 200 #endif
 201
 202
 203
 204 int main( int argc, char *argv[] )
 205 {
 206    void *buffer;
 207    int i;
 208    char *filename = NULL;
 209
 210    /* Create an RGBA-mode context */
 211 #if OSMESA_MAJOR_VERSION * 100 + OSMESA_MINOR_VERSION >= 305
 212    /* specify Z, stencil, accum sizes */
 213    OSMesaContext ctx = OSMesaCreateContextExt( OSMESA_RGBA, 16, 0, 0, NULL );
 214 #else
 215    OSMesaContext ctx = OSMesaCreateContext( OSMESA_RGBA, NULL );
 216 #endif
 217    if (!ctx) {
 218       printf("OSMesaCreateContext failed!\n");
 219       return 0;
 220    }
 221
 222    for ( i=1; i<argc; i++ ) {
 223       if (argv[i][0] != '-') filename = argv[i];
 224       if (strcmp(argv[i], "-perf")==0) perf = 1;
 225    }
 226
 227    /* Allocate the image buffer */
 228    buffer = malloc( WIDTH * HEIGHT * 4 * sizeof(GLubyte) );
 229    if (!buffer) {
 230       printf("Alloc image buffer failed!\n");
 231       return 0;
 232    }
 233
 234    /* Bind the buffer to the context and make it current */
 235    if (!OSMesaMakeCurrent( ctx, buffer, GL_UNSIGNED_BYTE, WIDTH, HEIGHT )) {
 236       printf("OSMesaMakeCurrent failed!\n");
 237       return 0;
 238    }
 239
 240
 241    {
 242       int z, s, a;
 243       glGetIntegerv(GL_DEPTH_BITS, &z);
 244       glGetIntegerv(GL_STENCIL_BITS, &s);
 245       glGetIntegerv(GL_ACCUM_RED_BITS, &a);
 246       printf("Depth=%d Stencil=%d Accum=%d\n", z, s, a);
 247    }
 248
 249    render_image();
 250    if (perf)
 251       for(i=0; i< 1000; i++)
 252          render_image();
 253
 254    if (filename != NULL) {
 255 #ifdef SAVE_TARGA
 256       write_targa(filename, buffer, WIDTH, HEIGHT);
 257 #else
 258       write_ppm(filename, buffer, WIDTH, HEIGHT);
 259 #endif
 260    }
 261    else {
 262       printf("Specify a filename if you want to make an image file\n");
 263    }
 264
 265    printf("all done\n");
 266
 267    /* free the image buffer */
 268    free( buffer );
 269
 270    /* destroy the context */
 271    OSMesaDestroyContext( ctx );
 272
 273    return 0;
 274 }