progs/osdemos/osdemo16.c

   1 /*
   2  * Demo of off-screen Mesa rendering with 16-bit color channels.
   3  * This requires the libOSMesa16.so library.
   4  *
   5  * Compile with something like this:
   6  *
   7  * gcc osdemo16.c -I../../include -L../../lib -lglut -lGLU -lOSMesa16 -lm -o osdemo16
   8  */
   9
  10
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include "GL/osmesa.h"
  15 #include "GL/glut.h"
  16
  17
  18 #define SAVE_TARGA
  19
  20
  21 #define WIDTH 400
  22 #define HEIGHT 400
  23
  24
  25
  26 static void render_image( void )
  27 {
  28    GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
  29    GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
  30    GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
  31    GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
  32    GLfloat red_mat[]   = { 1.0, 0.2, 0.2, 1.0 };
  33    GLfloat green_mat[] = { 0.2, 1.0, 0.2, 0.5 };
  34    GLfloat blue_mat[]  = { 0.2, 0.2, 1.0, 1.0 };
  35    GLfloat white_mat[]  = { 1.0, 1.0, 1.0, 1.0 };
  36    GLfloat purple_mat[] = { 1.0, 0.2, 1.0, 1.0 };
  37    GLUquadricObj *qobj = gluNewQuadric();
  38
  39    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
  40    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
  41    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
  42    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  43
  44    glEnable(GL_LIGHTING);
  45    glEnable(GL_LIGHT0);
  46    glEnable(GL_DEPTH_TEST);
  47
  48    glMatrixMode(GL_PROJECTION);
  49    glLoadIdentity();
  50    glOrtho(-2.5, 2.5, -2.5, 2.5, -10.0, 10.0);
  51    glMatrixMode(GL_MODELVIEW);
  52
  53    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  54
  55    glPushMatrix();
  56    glRotatef(20.0, 1.0, 0.0, 0.0);
  57
  58 #if 0
  59    glPushMatrix();
  60    glTranslatef(-0.75, 0.5, 0.0);
  61    glRotatef(90.0, 1.0, 0.0, 0.0);
  62    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red_mat );
  63    glutSolidTorus(0.275, 0.85, 20, 20);
  64    glPopMatrix();
  65 #endif
  66
  67    /* red square */
  68    glPushMatrix();
  69    glTranslatef(0.0, -0.5, 0.0);
  70    glRotatef(90, 1, 0.5, 0);
  71    glScalef(3, 3, 3);
  72    glDisable(GL_LIGHTING);
  73    glColor4f(1, 0, 0, 0.5);
  74    glBegin(GL_POLYGON);
  75    glVertex2f(-1, -1);
  76    glVertex2f( 1, -1);
  77    glVertex2f( 1,  1);
  78    glVertex2f(-1,  1);
  79    glEnd();
  80    glEnable(GL_LIGHTING);
  81    glPopMatrix();
  82
  83 #if 0
  84    /* green square */
  85    glPushMatrix();
  86    glTranslatef(0.0, 0.5, 0.1);
  87    glDisable(GL_LIGHTING);
  88    glColor3f(0, 1, 0);
  89    glBegin(GL_POLYGON);
  90    glVertex2f(-1, -1);
  91    glVertex2f( 1, -1);
  92    glVertex2f( 1,  1);
  93    glVertex2f(-1,  1);
  94    glEnd();
  95    glEnable(GL_LIGHTING);
  96    glPopMatrix();
  97
  98    /* blue square */
  99    glPushMatrix();
 100    glTranslatef(0.75, 0.5, 0.3);
 101    glDisable(GL_LIGHTING);
 102    glColor3f(0, 0, 0.5);
 103    glBegin(GL_POLYGON);
 104    glVertex2f(-1, -1);
 105    glVertex2f( 1, -1);
 106    glVertex2f( 1,  1);
 107    glVertex2f(-1,  1);
 108    glEnd();
 109    glEnable(GL_LIGHTING);
 110    glPopMatrix();
 111 #endif
 112    glPushMatrix();
 113    glTranslatef(-0.75, -0.5, 0.0);
 114    glRotatef(270.0, 1.0, 0.0, 0.0);
 115    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, green_mat );
 116    glColor4f(0,1,0,0.5);
 117    glEnable(GL_BLEND);
 118    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 119    gluCylinder(qobj, 1.0, 0.0, 2.0, 16, 1);
 120    glDisable(GL_BLEND);
 121    glPopMatrix();
 122
 123    glPushMatrix();
 124    glTranslatef(0.75, 1.0, 1.0);
 125    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue_mat );
 126    gluSphere(qobj, 1.0, 20, 20);
 127    glPopMatrix();
 128
 129    glPopMatrix();
 130
 131    /* This is very important!!!
 132     * Make sure buffered commands are finished!!!
 133     */
 134    glFinish();
 135
 136    gluDeleteQuadric(qobj);
 137
 138    {
 139       GLint r, g, b, a;
 140       glGetIntegerv(GL_RED_BITS, &r);
 141       glGetIntegerv(GL_GREEN_BITS, &g);
 142       glGetIntegerv(GL_BLUE_BITS, &b);
 143       glGetIntegerv(GL_ALPHA_BITS, &a);
 144       printf("channel sizes: %d %d %d %d\n", r, g, b, a);
 145    }
 146 }
 147
 148
 149
 150 static void
 151 write_targa(const char *filename, const GLushort *buffer, int width, int height)
 152 {
 153    FILE *f = fopen( filename, "w" );
 154    if (f) {
 155       int i, x, y;
 156       const GLushort *ptr = buffer;
 157       printf ("osdemo, writing tga file \n");
 158       fputc (0x00, f);  /* ID Length, 0 => No ID        */
 159       fputc (0x00, f);  /* Color Map Type, 0 => No color map included   */
 160       fputc (0x02, f);  /* Image Type, 2 => Uncompressed, True-color Image */
 161       fputc (0x00, f);  /* Next five bytes are about the color map entries */
 162       fputc (0x00, f);  /* 2 bytes Index, 2 bytes length, 1 byte size */
 163       fputc (0x00, f);
 164       fputc (0x00, f);
 165       fputc (0x00, f);
 166       fputc (0x00, f);  /* X-origin of Image    */
 167       fputc (0x00, f);
 168       fputc (0x00, f);  /* Y-origin of Image    */
 169       fputc (0x00, f);
 170       fputc (WIDTH & 0xff, f);      /* Image Width      */
 171       fputc ((WIDTH>>8) & 0xff, f);
 172       fputc (HEIGHT & 0xff, f);     /* Image Height     */
 173       fputc ((HEIGHT>>8) & 0xff, f);
 174       fputc (0x18, f);          /* Pixel Depth, 0x18 => 24 Bits */
 175       fputc (0x20, f);          /* Image Descriptor     */
 176       fclose(f);
 177       f = fopen( filename, "ab" );  /* reopen in binary append mode */
 178       for (y=height-1; y>=0; y--) {
 179          for (x=0; x<width; x++) {
 180             i = (y*width + x) * 4;
 181             /* just write 8 high bits */
 182             fputc(ptr[i+2] >> 8, f); /* write blue */
 183             fputc(ptr[i+1] >> 8, f); /* write green */
 184             fputc(ptr[i] >> 8, f);   /* write red */
 185          }
 186       }
 187    }
 188 }
 189
 190
 191 static void
 192 write_ppm(const char *filename, const GLushort *buffer, int width, int height)
 193 {
 194    const int binary = 0;
 195    FILE *f = fopen( filename, "w" );
 196    if (f) {
 197       int i, x, y;
 198       const GLushort *ptr = buffer;
 199       if (binary) {
 200          fprintf(f,"P6\n");
 201          fprintf(f,"# ppm-file created by osdemo.c\n");
 202          fprintf(f,"%i %i\n", width,height);
 203          fprintf(f,"255\n");
 204          fclose(f);
 205          f = fopen( filename, "ab" );  /* reopen in binary append mode */
 206          for (y=height-1; y>=0; y--) {
 207             for (x=0; x<width; x++) {
 208                i = (y*width + x) * 4;
 209                /* just write 8 high bits */
 210                fputc(ptr[i] >> 8, f);   /* write red */
 211                fputc(ptr[i+1] >> 8, f); /* write green */
 212                fputc(ptr[i+2] >> 8, f); /* write blue */
 213             }
 214          }
 215       }
 216       else {
 217          /*ASCII*/
 218          int counter = 0;
 219          fprintf(f,"P3\n");
 220          fprintf(f,"# ascii ppm file created by osdemo.c\n");
 221          fprintf(f,"%i %i\n", width, height);
 222          fprintf(f,"255\n");
 223          for (y=height-1; y>=0; y--) {
 224             for (x=0; x<width; x++) {
 225                i = (y*width + x) * 4;
 226                /* just write 8 high bits */
 227                fprintf(f, " %3d %3d %3d", ptr[i] >> 8, ptr[i+1] >> 8, ptr[i+2] >> 8);
 228                counter++;
 229                if (counter % 5 == 0)
 230                   fprintf(f, "\n");
 231             }
 232          }
 233       }
 234       fclose(f);
 235    }
 236 }
 237
 238
 239
 240 int main( int argc, char *argv[] )
 241 {
 242    GLushort *buffer;
 243
 244    /* Create an RGBA-mode context */
 245 #if OSMESA_MAJOR_VERSION * 100 + OSMESA_MINOR_VERSION >= 305
 246    /* specify Z, stencil, accum sizes */
 247    OSMesaContext ctx = OSMesaCreateContextExt( GL_RGBA, 16, 0, 0, NULL );
 248 #else
 249    OSMesaContext ctx = OSMesaCreateContext( GL_RGBA, NULL );
 250 #endif
 251    if (!ctx) {
 252       printf("OSMesaCreateContext failed!\n");
 253       return 0;
 254    }
 255
 256    /* Allocate the image buffer */
 257    buffer = (GLushort *) malloc( WIDTH * HEIGHT * 4 * sizeof(GLushort));
 258    if (!buffer) {
 259       printf("Alloc image buffer failed!\n");
 260       return 0;
 261    }
 262
 263    /* Bind the buffer to the context and make it current */
 264    if (!OSMesaMakeCurrent( ctx, buffer, GL_UNSIGNED_SHORT, WIDTH, HEIGHT )) {
 265       printf("OSMesaMakeCurrent failed!\n");
 266       return 0;
 267    }
 268
 269    render_image();
 270
 271    if (argc>1) {
 272 #ifdef SAVE_TARGA
 273       write_targa(argv[1], buffer, WIDTH, HEIGHT);
 274 #else
 275       write_ppm(argv[1], buffer, WIDTH, HEIGHT);
 276 #endif
 277    }
 278    else {
 279       printf("Specify a filename if you want to make an image file\n");
 280    }
 281
 282    printf("all done\n");
 283
 284    /* free the image buffer */
 285    free( buffer );
 286
 287    /* destroy the context */
 288    OSMesaDestroyContext( ctx );
 289
 290    return 0;
 291 }