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/*
* Demo of off-screen Mesa rendering with 32-bit float color channels.
* This requires the libOSMesa32.so library.
*
* Compile with something like this:
*
* gcc osdemo32.c -I../../include -L../../lib -lglut -lGLU -lOSMesa32 -lm -o osdemo32
*/
#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, 0.5 };
GLfloat blue_mat[] = { 0.2, 0.2, 1.0, 1.0 };
GLfloat white_mat[] = { 1.0, 1.0, 1.0, 1.0 };
GLfloat purple_mat[] = { 1.0, 0.2, 1.0, 1.0 };
GLUquadricObj *qobj = gluNewQuadric();
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);
#if 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();
#endif
/* red square */
glPushMatrix();
glTranslatef(0.0, -0.5, 0.0);
glRotatef(90, 1, 0.5, 0);
glScalef(3, 3, 3);
glDisable(GL_LIGHTING);
glColor4f(1, 0, 0, 0.5);
glBegin(GL_POLYGON);
glVertex2f(-1, -1);
glVertex2f( 1, -1);
glVertex2f( 1, 1);
glVertex2f(-1, 1);
glEnd();
glEnable(GL_LIGHTING);
glPopMatrix();
#if 0
/* green square */
glPushMatrix();
glTranslatef(0.0, 0.5, 0.1);
glDisable(GL_LIGHTING);
glColor3f(0, 1, 0);
glBegin(GL_POLYGON);
glVertex2f(-1, -1);
glVertex2f( 1, -1);
glVertex2f( 1, 1);
glVertex2f(-1, 1);
glEnd();
glEnable(GL_LIGHTING);
glPopMatrix();
/* blue square */
glPushMatrix();
glTranslatef(0.75, 0.5, 0.3);
glDisable(GL_LIGHTING);
glColor3f(0, 0, 0.5);
glBegin(GL_POLYGON);
glVertex2f(-1, -1);
glVertex2f( 1, -1);
glVertex2f( 1, 1);
glVertex2f(-1, 1);
glEnd();
glEnable(GL_LIGHTING);
glPopMatrix();
#endif
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 );
glColor4f(0,1,0,0.5);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
gluCylinder(qobj, 1.0, 0.0, 2.0, 16, 1);
glDisable(GL_BLEND);
glPopMatrix();
glPushMatrix();
glTranslatef(0.75, 1.0, 1.0);
glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue_mat );
gluSphere(qobj, 1.0, 20, 20);
glPopMatrix();
glPopMatrix();
/* This is very important!!!
* Make sure buffered commands are finished!!!
*/
glFinish();
gluDeleteQuadric(qobj);
{
GLint r, g, b, a;
glGetIntegerv(GL_RED_BITS, &r);
glGetIntegerv(GL_GREEN_BITS, &g);
glGetIntegerv(GL_BLUE_BITS, &b);
glGetIntegerv(GL_ALPHA_BITS, &a);
printf("channel sizes: %d %d %d %d\n", r, g, b, a);
}
}
static void
write_targa(const char *filename, const GLfloat *buffer, int width, int height)
{
FILE *f = fopen( filename, "w" );
if (f) {
int i, x, y;
const GLfloat *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++) {
int r, g, b;
i = (y*width + x) * 4;
r = (int) (ptr[i+0] * 255.0);
g = (int) (ptr[i+1] * 255.0);
b = (int) (ptr[i+2] * 255.0);
if (r > 255) r = 255;
if (g > 255) g = 255;
if (b > 255) b = 255;
fputc(b, f); /* write blue */
fputc(g, f); /* write green */
fputc(r, f); /* write red */
}
}
}
}
static void
write_ppm(const char *filename, const GLfloat *buffer, int width, int height)
{
const int binary = 0;
FILE *f = fopen( filename, "w" );
if (f) {
int i, x, y;
const GLfloat *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++) {
int r, g, b;
i = (y*width + x) * 4;
r = (int) (ptr[i+0] * 255.0);
g = (int) (ptr[i+1] * 255.0);
b = (int) (ptr[i+2] * 255.0);
if (r > 255) r = 255;
if (g > 255) g = 255;
if (b > 255) b = 255;
fputc(r, f); /* write red */
fputc(g, f); /* write green */
fputc(b, 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++) {
int r, g, b;
i = (y*width + x) * 4;
r = (int) (ptr[i+0] * 255.0);
g = (int) (ptr[i+1] * 255.0);
b = (int) (ptr[i+2] * 255.0);
if (r > 255) r = 255;
if (g > 255) g = 255;
if (b > 255) b = 255;
fprintf(f, " %3d %3d %3d", r, g, b);
counter++;
if (counter % 5 == 0)
fprintf(f, "\n");
}
}
}
fclose(f);
}
}
int main( int argc, char *argv[] )
{
GLfloat *buffer;
/* Create an RGBA-mode context */
#if OSMESA_MAJOR_VERSION * 100 + OSMESA_MINOR_VERSION >= 305
/* specify Z, stencil, accum sizes */
OSMesaContext ctx = OSMesaCreateContextExt( GL_RGBA, 16, 0, 0, NULL );
#else
OSMesaContext ctx = OSMesaCreateContext( GL_RGBA, NULL );
#endif
if (!ctx) {
printf("OSMesaCreateContext failed!\n");
return 0;
}
/* Allocate the image buffer */
buffer = (GLfloat *) malloc( WIDTH * HEIGHT * 4 * sizeof(GLfloat));
if (!buffer) {
printf("Alloc image buffer failed!\n");
return 0;
}
/* Bind the buffer to the context and make it current */
if (!OSMesaMakeCurrent( ctx, buffer, GL_FLOAT, WIDTH, HEIGHT )) {
printf("OSMesaMakeCurrent failed!\n");
return 0;
}
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;
}
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