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
30static int Width = 400;
31static int Height = 400;
32
33
34static void
35Sphere(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
44static void
45Cone(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
55static void
56Torus(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
96static void
97render_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
158static void
159write_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
199static void
200write_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
248int
249main(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}
324