src/osdemos/osdemo.c

   1 /*
   2  * Demo of off-screen Mesa rendering
   3  *
   4  * See Mesa/include/GL/osmesa.h for documentation of the OSMesa functions.
   5  *
   6  * If you want to render BIG images you'll probably have to increase
   7  * MAX_WIDTH and MAX_Height in src/config.h.
   8  *
   9  * This program is in the public domain.
  10  *
  11  * Brian Paul
  12  *
  13  * PPM output provided by Joerg Schmalzl.
  14  * ASCII PPM output added by Brian Paul.
  15  *
  16  * Usage: osdemo [filename]
  17  */
  18
  19
  20 #include <math.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include "GL/osmesa.h"
  25 #include "gl_wrap.h"
  26
  27
  28 #define SAVE_TARGA
  29
  30 static int Width = 400;
  31 static int Height = 400;
  32
  33
  34 static void
  35 Sphere(float radius, int slices, int stacks)
  36 {
  37    GLUquadric *q = gluNewQuadric();
  38    gluQuadricNormals(q, GLU_SMOOTH);
  39    gluSphere(q, radius, slices, stacks);
  40    gluDeleteQuadric(q);
  41 }
  42
  43
  44 static void
  45 Cone(float base, float height, int slices, int stacks)
  46 {
  47    GLUquadric *q = gluNewQuadric();
  48    gluQuadricDrawStyle(q, GLU_FILL);
  49    gluQuadricNormals(q, GLU_SMOOTH);
  50    gluCylinder(q, base, 0.0, height, slices, stacks);
  51    gluDeleteQuadric(q);
  52 }
  53
  54
  55 static void
  56 Torus(float innerRadius, float outerRadius, int sides, int rings)
  57 {
  58    /* from GLUT... */
  59    int i, j;
  60    GLfloat theta, phi, theta1;
  61    GLfloat cosTheta, sinTheta;
  62    GLfloat cosTheta1, sinTheta1;
  63    const GLfloat ringDelta = 2.0 * M_PI / rings;
  64    const GLfloat sideDelta = 2.0 * M_PI / sides;
  65
  66    theta = 0.0;
  67    cosTheta = 1.0;
  68    sinTheta = 0.0;
  69    for (i = rings - 1; i >= 0; i--) {
  70       theta1 = theta + ringDelta;
  71       cosTheta1 = cos(theta1);
  72       sinTheta1 = sin(theta1);
  73       glBegin(GL_QUAD_STRIP);
  74       phi = 0.0;
  75       for (j = sides; j >= 0; j--) {
  76          GLfloat cosPhi, sinPhi, dist;
  77
  78          phi += sideDelta;
  79          cosPhi = cos(phi);
  80          sinPhi = sin(phi);
  81          dist = outerRadius + innerRadius * cosPhi;
  82
  83          glNormal3f(cosTheta1 * cosPhi, -sinTheta1 * cosPhi, sinPhi);
  84          glVertex3f(cosTheta1 * dist, -sinTheta1 * dist, innerRadius * sinPhi);
  85          glNormal3f(cosTheta * cosPhi, -sinTheta * cosPhi, sinPhi);
  86          glVertex3f(cosTheta * dist, -sinTheta * dist,  innerRadius * sinPhi);
  87       }
  88       glEnd();
  89       theta = theta1;
  90       cosTheta = cosTheta1;
  91       sinTheta = sinTheta1;
  92    }
  93 }
  94
  95
  96 static void
  97 render_image(void)
  98 {
  99    GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
 100    GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
 101    GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
 102    GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
 103    GLfloat red_mat[]   = { 1.0, 0.2, 0.2, 1.0 };
 104    GLfloat green_mat[] = { 0.2, 1.0, 0.2, 1.0 };
 105    GLfloat blue_mat[]  = { 0.2, 0.2, 1.0, 1.0 };
 106
 107
 108    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
 109    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
 110    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
 111    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
 112
 113    glEnable(GL_LIGHTING);
 114    glEnable(GL_LIGHT0);
 115    glEnable(GL_DEPTH_TEST);
 116
 117    glMatrixMode(GL_PROJECTION);
 118    glLoadIdentity();
 119    glOrtho(-2.5, 2.5, -2.5, 2.5, -10.0, 10.0);
 120    glMatrixMode(GL_MODELVIEW);
 121
 122    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
 123
 124    glPushMatrix();
 125    glRotatef(20.0, 1.0, 0.0, 0.0);
 126
 127    glPushMatrix();
 128    glTranslatef(-0.75, 0.5, 0.0);
 129    glRotatef(90.0, 1.0, 0.0, 0.0);
 130    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red_mat );
 131    Torus(0.275, 0.85, 20, 20);
 132    glPopMatrix();
 133
 134    glPushMatrix();
 135    glTranslatef(-0.75, -0.5, 0.0);
 136    glRotatef(270.0, 1.0, 0.0, 0.0);
 137    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, green_mat );
 138    Cone(1.0, 2.0, 16, 1);
 139    glPopMatrix();
 140
 141    glPushMatrix();
 142    glTranslatef(0.75, 0.0, -1.0);
 143    glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue_mat );
 144    Sphere(1.0, 20, 20);
 145    glPopMatrix();
 146
 147    glPopMatrix();
 148
 149    /* This is very important!!!
 150     * Make sure buffered commands are finished!!!
 151     */
 152    glFinish();
 153 }
 154
 155
 156 #ifdef SAVE_TARGA
 157
 158 static void
 159 write_targa(const char *filename, const GLubyte *buffer, int width, int height)
 160 {
 161    FILE *f = fopen( filename, "w" );
 162    if (f) {
 163       int i, x, y;
 164       const GLubyte *ptr = buffer;
 165       printf ("osdemo, writing tga file \n");
 166       fputc (0x00, f);  /* ID Length, 0 => No ID        */
 167       fputc (0x00, f);  /* Color Map Type, 0 => No color map included   */
 168       fputc (0x02, f);  /* Image Type, 2 => Uncompressed, True-color Image */
 169       fputc (0x00, f);  /* Next five bytes are about the color map entries */
 170       fputc (0x00, f);  /* 2 bytes Index, 2 bytes length, 1 byte size */
 171       fputc (0x00, f);
 172       fputc (0x00, f);
 173       fputc (0x00, f);
 174       fputc (0x00, f);  /* X-origin of Image    */
 175       fputc (0x00, f);
 176       fputc (0x00, f);  /* Y-origin of Image    */
 177       fputc (0x00, f);
 178       fputc (Width & 0xff, f);      /* Image Width      */
 179       fputc ((Width>>8) & 0xff, f);
 180       fputc (Height & 0xff, f);     /* Image Height     */
 181       fputc ((Height>>8) & 0xff, f);
 182       fputc (0x18, f);          /* Pixel Depth, 0x18 => 24 Bits */
 183       fputc (0x20, f);          /* Image Descriptor     */
 184       fclose(f);
 185       f = fopen( filename, "ab" );  /* reopen in binary append mode */
 186       for (y=height-1; y>=0; y--) {
 187          for (x=0; x<width; x++) {
 188             i = (y*width + x) * 4;
 189             fputc(ptr[i+2], f); /* write blue */
 190             fputc(ptr[i+1], f); /* write green */
 191             fputc(ptr[i], f);   /* write red */
 192          }
 193       }
 194    }
 195 }
 196
 197 #else
 198
 199 static void
 200 write_ppm(const char *filename, const GLubyte *buffer, int width, int height)
 201 {
 202    const int binary = 0;
 203    FILE *f = fopen( filename, "w" );
 204    if (f) {
 205       int i, x, y;
 206       const GLubyte *ptr = buffer;
 207       if (binary) {
 208          fprintf(f,"P6\n");
 209          fprintf(f,"# ppm-file created by osdemo.c\n");
 210          fprintf(f,"%i %i\n", width,height);
 211          fprintf(f,"255\n");
 212          fclose(f);
 213          f = fopen( filename, "ab" );  /* reopen in binary append mode */
 214          for (y=height-1; y>=0; y--) {
 215             for (x=0; x<width; x++) {
 216                i = (y*width + x) * 4;
 217                fputc(ptr[i], f);   /* write red */
 218                fputc(ptr[i+1], f); /* write green */
 219                fputc(ptr[i+2], f); /* write blue */
 220             }
 221          }
 222       }
 223       else {
 224          /*ASCII*/
 225          int counter = 0;
 226          fprintf(f,"P3\n");
 227          fprintf(f,"# ascii ppm file created by osdemo.c\n");
 228          fprintf(f,"%i %i\n", width, height);
 229          fprintf(f,"255\n");
 230          for (y=height-1; y>=0; y--) {
 231             for (x=0; x<width; x++) {
 232                i = (y*width + x) * 4;
 233                fprintf(f, " %3d %3d %3d", ptr[i], ptr[i+1], ptr[i+2]);
 234                counter++;
 235                if (counter % 5 == 0)
 236                   fprintf(f, "\n");
 237             }
 238          }
 239       }
 240       fclose(f);
 241    }
 242 }
 243
 244 #endif
 245
 246
 247
 248 int
 249 main(int argc, char *argv[])
 250 {
 251    OSMesaContext ctx;
 252    void *buffer;
 253    char *filename = NULL;
 254
 255    if (argc < 2) {
 256       fprintf(stderr, "Usage:\n");
 257       fprintf(stderr, "  osdemo filename [width height]\n");
 258       return 0;
 259    }
 260
 261    filename = argv[1];
 262    if (argc == 4) {
 263       Width = atoi(argv[2]);
 264       Height = atoi(argv[3]);
 265    }
 266
 267    /* Create an RGBA-mode context */
 268 #if OSMESA_MAJOR_VERSION * 100 + OSMESA_MINOR_VERSION >= 305
 269    /* specify Z, stencil, accum sizes */
 270    ctx = OSMesaCreateContextExt( OSMESA_RGBA, 16, 0, 0, NULL );
 271 #else
 272    ctx = OSMesaCreateContext( OSMESA_RGBA, NULL );
 273 #endif
 274    if (!ctx) {
 275       printf("OSMesaCreateContext failed!\n");
 276       return 0;
 277    }
 278
 279    /* Allocate the image buffer */
 280    buffer = malloc( Width * Height * 4 * sizeof(GLubyte) );
 281    if (!buffer) {
 282       printf("Alloc image buffer failed!\n");
 283       return 0;
 284    }
 285
 286    /* Bind the buffer to the context and make it current */
 287    if (!OSMesaMakeCurrent( ctx, buffer, GL_UNSIGNED_BYTE, Width, Height )) {
 288       printf("OSMesaMakeCurrent failed!\n");
 289       return 0;
 290    }
 291
 292
 293    {
 294       int z, s, a;
 295       glGetIntegerv(GL_DEPTH_BITS, &z);
 296       glGetIntegerv(GL_STENCIL_BITS, &s);
 297       glGetIntegerv(GL_ACCUM_RED_BITS, &a);
 298       printf("Depth=%d Stencil=%d Accum=%d\n", z, s, a);
 299    }
 300
 301    render_image();
 302
 303    if (filename != NULL) {
 304 #ifdef SAVE_TARGA
 305       write_targa(filename, buffer, Width, Height);
 306 #else
 307       write_ppm(filename, buffer, Width, Height);
 308 #endif
 309    }
 310    else {
 311       printf("Specify a filename if you want to make an image file\n");
 312    }
 313
 314    printf("all done\n");
 315
 316    /* free the image buffer */
 317    free( buffer );
 318
 319    /* destroy the context */
 320    OSMesaDestroyContext( ctx );
 321
 322    return 0;
 323 }