progs/osdemos/osdemo32.c

   1 /*
   2  * Demo of off-screen Mesa rendering with 32-bit float color channels.
   3  * This requires the libOSMesa32.so library.
   4  *
   5  * Compile with something like this:
   6  *
   7  * gcc osdemo32.c -I../../include -L../../lib -lglut -lGLU -lOSMesa32 -lm -o osdemo32
   8  */
   9
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include "GL/osmesa.h"
  14 #include "GL/glut.h"
  15
  16
  17 #define SAVE_TARGA
  18
  19
  20 #define WIDTH 400
  21 #define HEIGHT 400
  22
  23
  24
  25 static void render_image( void )
  26 {
  27    GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
  28    GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
  29    GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
  30    GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
  31    GLfloat red_mat[]   = { 1.0, 0.2, 0.2, 1.0 };
  32    GLfloat green_mat[] = { 0.2, 1.0, 0.2, 0.5 };
  33    GLfloat blue_mat[]  = { 0.2, 0.2, 1.0, 1.0 };
  34    GLfloat white_mat[]  = { 1.0, 1.0, 1.0, 1.0 };
  35    GLfloat purple_mat[] = { 1.0, 0.2, 1.0, 1.0 };
  36    GLUquadricObj *qobj = gluNewQuadric();
  37
  38    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
  39    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
  40    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
  41    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  42
  43    glEnable(GL_LIGHTING);
  44    glEnable(GL_LIGHT0);
  45    glEnable(GL_DEPTH_TEST);
  46
  47    glMatrixMode(GL_PROJECTION);
  48    glLoadIdentity();
  49    glOrtho(-2.5, 2.5, -2.5, 2.5, -10.0, 10.0);
  50    glMatrixMode(GL_MODELVIEW);
  51
  52    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  53
  54    glPushMatrix();
  55    glRotatef(20.0, 1.0, 0.0, 0.0);
  56
  57 #if 0
  58    glPushMatrix();
  59    glTranslatef(-0.75, 0.5, 0.0);
  60    glRotatef(90.0, 1.0, 0.0, 0.0);
  61    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red_mat );
  62    glutSolidTorus(0.275, 0.85, 20, 20);
  63    glPopMatrix();
  64 #endif
  65
  66    /* red square */
  67    glPushMatrix();
  68    glTranslatef(0.0, -0.5, 0.0);
  69    glRotatef(90, 1, 0.5, 0);
  70    glScalef(3, 3, 3);
  71    glDisable(GL_LIGHTING);
  72    glColor4f(1, 0, 0, 0.5);
  73    glBegin(GL_POLYGON);
  74    glVertex2f(-1, -1);
  75    glVertex2f( 1, -1);
  76    glVertex2f( 1,  1);
  77    glVertex2f(-1,  1);
  78    glEnd();
  79    glEnable(GL_LIGHTING);
  80    glPopMatrix();
  81
  82 #if 0
  83    /* green square */
  84    glPushMatrix();
  85    glTranslatef(0.0, 0.5, 0.1);
  86    glDisable(GL_LIGHTING);
  87    glColor3f(0, 1, 0);
  88    glBegin(GL_POLYGON);
  89    glVertex2f(-1, -1);
  90    glVertex2f( 1, -1);
  91    glVertex2f( 1,  1);
  92    glVertex2f(-1,  1);
  93    glEnd();
  94    glEnable(GL_LIGHTING);
  95    glPopMatrix();
  96
  97    /* blue square */
  98    glPushMatrix();
  99    glTranslatef(0.75, 0.5, 0.3);
 100    glDisable(GL_LIGHTING);
 101    glColor3f(0, 0, 0.5);
 102    glBegin(GL_POLYGON);
 103    glVertex2f(-1, -1);
 104    glVertex2f( 1, -1);
 105    glVertex2f( 1,  1);
 106    glVertex2f(-1,  1);
 107    glEnd();
 108    glEnable(GL_LIGHTING);
 109    glPopMatrix();
 110 #endif
 111    glPushMatrix();
 112    glTranslatef(-0.75, -0.5, 0.0);
 113    glRotatef(270.0, 1.0, 0.0, 0.0);
 114    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, green_mat );
 115    glColor4f(0,1,0,0.5);
 116    glEnable(GL_BLEND);
 117    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 118    gluCylinder(qobj, 1.0, 0.0, 2.0, 16, 1);
 119    glDisable(GL_BLEND);
 120    glPopMatrix();
 121
 122    glPushMatrix();
 123    glTranslatef(0.75, 1.0, 1.0);
 124    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue_mat );
 125    gluSphere(qobj, 1.0, 20, 20);
 126    glPopMatrix();
 127
 128    glPopMatrix();
 129
 130    /* This is very important!!!
 131     * Make sure buffered commands are finished!!!
 132     */
 133    glFinish();
 134
 135    gluDeleteQuadric(qobj);
 136
 137    {
 138       GLint r, g, b, a;
 139       glGetIntegerv(GL_RED_BITS, &r);
 140       glGetIntegerv(GL_GREEN_BITS, &g);
 141       glGetIntegerv(GL_BLUE_BITS, &b);
 142       glGetIntegerv(GL_ALPHA_BITS, &a);
 143       printf("channel sizes: %d %d %d %d\n", r, g, b, a);
 144    }
 145 }
 146
 147
 148
 149 static void
 150 write_targa(const char *filename, const GLfloat *buffer, int width, int height)
 151 {
 152    FILE *f = fopen( filename, "w" );
 153    if (f) {
 154       int i, x, y;
 155       const GLfloat *ptr = buffer;
 156       printf ("osdemo, writing tga file \n");
 157       fputc (0x00, f);  /* ID Length, 0 => No ID        */
 158       fputc (0x00, f);  /* Color Map Type, 0 => No color map included   */
 159       fputc (0x02, f);  /* Image Type, 2 => Uncompressed, True-color Image */
 160       fputc (0x00, f);  /* Next five bytes are about the color map entries */
 161       fputc (0x00, f);  /* 2 bytes Index, 2 bytes length, 1 byte size */
 162       fputc (0x00, f);
 163       fputc (0x00, f);
 164       fputc (0x00, f);
 165       fputc (0x00, f);  /* X-origin of Image    */
 166       fputc (0x00, f);
 167       fputc (0x00, f);  /* Y-origin of Image    */
 168       fputc (0x00, f);
 169       fputc (WIDTH & 0xff, f);      /* Image Width      */
 170       fputc ((WIDTH>>8) & 0xff, f);
 171       fputc (HEIGHT & 0xff, f);     /* Image Height     */
 172       fputc ((HEIGHT>>8) & 0xff, f);
 173       fputc (0x18, f);          /* Pixel Depth, 0x18 => 24 Bits */
 174       fputc (0x20, f);          /* Image Descriptor     */
 175       fclose(f);
 176       f = fopen( filename, "ab" );  /* reopen in binary append mode */
 177       for (y=height-1; y>=0; y--) {
 178          for (x=0; x<width; x++) {
 179             int r, g, b;
 180             i = (y*width + x) * 4;
 181             r = (int) (ptr[i+0] * 255.0);
 182             g = (int) (ptr[i+1] * 255.0);
 183             b = (int) (ptr[i+2] * 255.0);
 184             if (r > 255) r = 255;
 185             if (g > 255) g = 255;
 186             if (b > 255) b = 255;
 187             fputc(b, f); /* write blue */
 188             fputc(g, f); /* write green */
 189             fputc(r, f); /* write red */
 190          }
 191       }
 192    }
 193 }
 194
 195
 196 static void
 197 write_ppm(const char *filename, const GLfloat *buffer, int width, int height)
 198 {
 199    const int binary = 0;
 200    FILE *f = fopen( filename, "w" );
 201    if (f) {
 202       int i, x, y;
 203       const GLfloat *ptr = buffer;
 204       if (binary) {
 205          fprintf(f,"P6\n");
 206          fprintf(f,"# ppm-file created by osdemo.c\n");
 207          fprintf(f,"%i %i\n", width,height);
 208          fprintf(f,"255\n");
 209          fclose(f);
 210          f = fopen( filename, "ab" );  /* reopen in binary append mode */
 211          for (y=height-1; y>=0; y--) {
 212             for (x=0; x<width; x++) {
 213                int r, g, b;
 214                i = (y*width + x) * 4;
 215                r = (int) (ptr[i+0] * 255.0);
 216                g = (int) (ptr[i+1] * 255.0);
 217                b = (int) (ptr[i+2] * 255.0);
 218                if (r > 255) r = 255;
 219                if (g > 255) g = 255;
 220                if (b > 255) b = 255;
 221                fputc(r, f);   /* write red */
 222                fputc(g, f); /* write green */
 223                fputc(b, f); /* write blue */
 224             }
 225          }
 226       }
 227       else {
 228          /*ASCII*/
 229          int counter = 0;
 230          fprintf(f,"P3\n");
 231          fprintf(f,"# ascii ppm file created by osdemo.c\n");
 232          fprintf(f,"%i %i\n", width, height);
 233          fprintf(f,"255\n");
 234          for (y=height-1; y>=0; y--) {
 235             for (x=0; x<width; x++) {
 236                int r, g, b;
 237                i = (y*width + x) * 4;
 238                r = (int) (ptr[i+0] * 255.0);
 239                g = (int) (ptr[i+1] * 255.0);
 240                b = (int) (ptr[i+2] * 255.0);
 241                if (r > 255) r = 255;
 242                if (g > 255) g = 255;
 243                if (b > 255) b = 255;
 244                fprintf(f, " %3d %3d %3d", r, g, b);
 245                counter++;
 246                if (counter % 5 == 0)
 247                   fprintf(f, "\n");
 248             }
 249          }
 250       }
 251       fclose(f);
 252    }
 253 }
 254
 255
 256
 257 int main( int argc, char *argv[] )
 258 {
 259    GLfloat *buffer;
 260
 261    /* Create an RGBA-mode context */
 262 #if OSMESA_MAJOR_VERSION * 100 + OSMESA_MINOR_VERSION >= 305
 263    /* specify Z, stencil, accum sizes */
 264    OSMesaContext ctx = OSMesaCreateContextExt( GL_RGBA, 16, 0, 0, NULL );
 265 #else
 266    OSMesaContext ctx = OSMesaCreateContext( GL_RGBA, NULL );
 267 #endif
 268    if (!ctx) {
 269       printf("OSMesaCreateContext failed!\n");
 270       return 0;
 271    }
 272
 273    /* Allocate the image buffer */
 274    buffer = (GLfloat *) malloc( WIDTH * HEIGHT * 4 * sizeof(GLfloat));
 275    if (!buffer) {
 276       printf("Alloc image buffer failed!\n");
 277       return 0;
 278    }
 279
 280    /* Bind the buffer to the context and make it current */
 281    if (!OSMesaMakeCurrent( ctx, buffer, GL_FLOAT, WIDTH, HEIGHT )) {
 282       printf("OSMesaMakeCurrent failed!\n");
 283       return 0;
 284    }
 285
 286    render_image();
 287
 288    if (argc>1) {
 289 #ifdef SAVE_TARGA
 290       write_targa(argv[1], buffer, WIDTH, HEIGHT);
 291 #else
 292       write_ppm(argv[1], buffer, WIDTH, HEIGHT);
 293 #endif
 294    }
 295    else {
 296       printf("Specify a filename if you want to make an image file\n");
 297    }
 298
 299    printf("all done\n");
 300
 301    /* free the image buffer */
 302    free( buffer );
 303
 304    /* destroy the context */
 305    OSMesaDestroyContext( ctx );
 306
 307    return 0;
 308 }