/* $Id: osdemo.c,v 1.4 2000/03/28 16:59:39 rjfrank Exp $ */
/*
* Demo of off-screen Mesa rendering
*
* See Mesa/include/GL/osmesa.h for documentation of the OSMesa functions.
*
* If you want to render BIG images you'll probably have to increase
* MAX_WIDTH and MAX_HEIGHT in src/config.h.
*
* This program is in the public domain.
*
* Brian Paul
*
* PPM output provided by Joerg Schmalzl.
* ASCII PPM output added by Brian Paul.
*/
#include <stdio.h>
#include <stdlib.h>
#include "GL/osmesa.h"
#include "GL/glut.h"
#define SAVE_TARGA
#define WIDTH 400
#define HEIGHT 400
static void render_image( void )
{
GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
GLfloat red_mat[] = { 1.0, 0.2, 0.2, 1.0 };
GLfloat green_mat[] = { 0.2, 1.0, 0.2, 1.0 };
GLfloat blue_mat[] = { 0.2, 0.2, 1.0, 1.0 };
glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
glLightfv(GL_LIGHT0, GL_POSITION, light_position);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_DEPTH_TEST);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-2.5, 2.5, -2.5, 2.5, -10.0, 10.0);
glMatrixMode(GL_MODELVIEW);
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glPushMatrix();
glRotatef(20.0, 1.0, 0.0, 0.0);
glPushMatrix();
glTranslatef(-0.75, 0.5, 0.0);
glRotatef(90.0, 1.0, 0.0, 0.0);
glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red_mat );
glutSolidTorus(0.275, 0.85, 20, 20);
glPopMatrix();
glPushMatrix();
glTranslatef(-0.75, -0.5, 0.0);
glRotatef(270.0, 1.0, 0.0, 0.0);
glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, green_mat );
glutSolidCone(1.0, 2.0, 16, 1);
glPopMatrix();
#ifdef GL_HP_occlusion_test
{
GLboolean bRet;
glDepthMask(GL_FALSE);
glColorMask(GL_FALSE,GL_FALSE,GL_FALSE,GL_FALSE);
glEnable(GL_OCCLUSION_TEST_HP);
glGetBooleanv(GL_OCCLUSION_TEST_RESULT_HP,&bRet);
glPushMatrix();
glTranslatef(0.75, 0.0, -1.0);
glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue_mat );
glutSolidSphere(1.0, 20, 20);
glPopMatrix();
glGetBooleanv(GL_OCCLUSION_TEST_RESULT_HP,&bRet);
printf("Occlusion test 1 (result should be 1): %d\n",bRet);
glDepthMask(GL_TRUE);
glColorMask(GL_TRUE,GL_TRUE,GL_TRUE,GL_TRUE);
glDisable(GL_OCCLUSION_TEST_HP);
}
#endif
glPushMatrix();
glTranslatef(0.75, 0.0, -1.0);
glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue_mat );
glutSolidSphere(1.0, 20, 20);
glPopMatrix();
#ifdef GL_HP_occlusion_test
{
GLboolean bRet;
glDepthMask(GL_FALSE);
glColorMask(GL_FALSE,GL_FALSE,GL_FALSE,GL_FALSE);
glEnable(GL_OCCLUSION_TEST_HP);
glGetBooleanv(GL_OCCLUSION_TEST_RESULT_HP,&bRet);
/* draw a sphere inside the previous sphere */
glPushMatrix();
glTranslatef(0.75, 0.0, -1.0);
glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue_mat );
glutSolidSphere(0.5, 20, 20);
glPopMatrix();
glGetBooleanv(GL_OCCLUSION_TEST_RESULT_HP,&bRet);
printf("Occlusion test 2 (result should be 0): %d\n",bRet);
glDepthMask(GL_TRUE);
glColorMask(GL_TRUE,GL_TRUE,GL_TRUE,GL_TRUE);
glDisable(GL_OCCLUSION_TEST_HP);
}
#endif
glPopMatrix();
}
static void
write_targa(const char *filename, const GLubyte *buffer, int width, int height)
{
FILE *f = fopen( filename, "w" );
if (f) {
int i, x, y;
const GLubyte *ptr = buffer;
printf ("osdemo, writing tga file \n");
fputc (0x00, f); /* ID Length, 0 => No ID */
fputc (0x00, f); /* Color Map Type, 0 => No color map included */
fputc (0x02, f); /* Image Type, 2 => Uncompressed, True-color Image */
fputc (0x00, f); /* Next five bytes are about the color map entries */
fputc (0x00, f); /* 2 bytes Index, 2 bytes length, 1 byte size */
fputc (0x00, f);
fputc (0x00, f);
fputc (0x00, f);
fputc (0x00, f); /* X-origin of Image */
fputc (0x00, f);
fputc (0x00, f); /* Y-origin of Image */
fputc (0x00, f);
fputc (WIDTH & 0xff, f); /* Image Width */
fputc ((WIDTH>>8) & 0xff, f);
fputc (HEIGHT & 0xff, f); /* Image Height */
fputc ((HEIGHT>>8) & 0xff, f);
fputc (0x18, f); /* Pixel Depth, 0x18 => 24 Bits */
fputc (0x20, f); /* Image Descriptor */
fclose(f);
f = fopen( filename, "ab" ); /* reopen in binary append mode */
for (y=height-1; y>=0; y--) {
for (x=0; x<width; x++) {
i = (y*width + x) * 4;
fputc(ptr[i+2], f); /* write blue */
fputc(ptr[i+1], f); /* write green */
fputc(ptr[i], f); /* write red */
}
}
}
}
static void
write_ppm(const char *filename, const GLubyte *buffer, int width, int height)
{
const int binary = 0;
FILE *f = fopen( filename, "w" );
if (f) {
int i, x, y;
const GLubyte *ptr = buffer;
if (binary) {
fprintf(f,"P6\n");
fprintf(f,"# ppm-file created by osdemo.c\n");
fprintf(f,"%i %i\n", width,height);
fprintf(f,"255\n");
fclose(f);
f = fopen( filename, "ab" ); /* reopen in binary append mode */
for (y=height-1; y>=0; y--) {
for (x=0; x<width; x++) {
i = (y*width + x) * 4;
fputc(ptr[i], f); /* write red */
fputc(ptr[i+1], f); /* write green */
fputc(ptr[i+2], f); /* write blue */
}
}
}
else {
/*ASCII*/
int counter = 0;
fprintf(f,"P3\n");
fprintf(f,"# ascii ppm file created by osdemo.c\n");
fprintf(f,"%i %i\n", width, height);
fprintf(f,"255\n");
for (y=height-1; y>=0; y--) {
for (x=0; x<width; x++) {
i = (y*width + x) * 4;
fprintf(f, " %3d %3d %3d", ptr[i], ptr[i+1], ptr[i+2]);
counter++;
if (counter % 5 == 0)
fprintf(f, "\n");
}
}
}
fclose(f);
}
}
int main( int argc, char *argv[] )
{
/* Create an RGBA-mode context */
OSMesaContext ctx = OSMesaCreateContext( GL_RGBA, NULL );
/* Allocate the image buffer */
void *buffer = malloc( WIDTH * HEIGHT * 4 );
/* Bind the buffer to the context and make it current */
OSMesaMakeCurrent( ctx, buffer, GL_UNSIGNED_BYTE, WIDTH, HEIGHT );
render_image();
if (argc>1) {
#ifdef SAVE_TARGA
write_targa(argv[1], buffer, WIDTH, HEIGHT);
#else
write_ppm(argv[1], buffer, WIDTH, HEIGHT);
#endif
}
else {
printf("Specify a filename if you want to make an image file\n");
}
printf("all done\n");
/* free the image buffer */
free( buffer );
/* destroy the context */
OSMesaDestroyContext( ctx );
return 0;
}