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/*
* 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.
*
* Usage: osdemo [filename]
*/
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "GL/osmesa.h"
#include "gl_wrap.h"
#define SAVE_TARGA
static int Width = 400;
static int Height = 400;
static void
Sphere(float radius, int slices, int stacks)
{
GLUquadric *q = gluNewQuadric();
gluQuadricNormals(q, GLU_SMOOTH);
gluSphere(q, radius, slices, stacks);
gluDeleteQuadric(q);
}
static void
Cone(float base, float height, int slices, int stacks)
{
GLUquadric *q = gluNewQuadric();
gluQuadricDrawStyle(q, GLU_FILL);
gluQuadricNormals(q, GLU_SMOOTH);
gluCylinder(q, base, 0.0, height, slices, stacks);
gluDeleteQuadric(q);
}
static void
Torus(float innerRadius, float outerRadius, int sides, int rings)
{
/* from GLUT... */
int i, j;
GLfloat theta, phi, theta1;
GLfloat cosTheta, sinTheta;
GLfloat cosTheta1, sinTheta1;
const GLfloat ringDelta = 2.0 * M_PI / rings;
const GLfloat sideDelta = 2.0 * M_PI / sides;
theta = 0.0;
cosTheta = 1.0;
sinTheta = 0.0;
for (i = rings - 1; i >= 0; i--) {
theta1 = theta + ringDelta;
cosTheta1 = cos(theta1);
sinTheta1 = sin(theta1);
glBegin(GL_QUAD_STRIP);
phi = 0.0;
for (j = sides; j >= 0; j--) {
GLfloat cosPhi, sinPhi, dist;
phi += sideDelta;
cosPhi = cos(phi);
sinPhi = sin(phi);
dist = outerRadius + innerRadius * cosPhi;
glNormal3f(cosTheta1 * cosPhi, -sinTheta1 * cosPhi, sinPhi);
glVertex3f(cosTheta1 * dist, -sinTheta1 * dist, innerRadius * sinPhi);
glNormal3f(cosTheta * cosPhi, -sinTheta * cosPhi, sinPhi);
glVertex3f(cosTheta * dist, -sinTheta * dist, innerRadius * sinPhi);
}
glEnd();
theta = theta1;
cosTheta = cosTheta1;
sinTheta = sinTheta1;
}
}
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 );
Torus(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 );
Cone(1.0, 2.0, 16, 1);
glPopMatrix();
glPushMatrix();
glTranslatef(0.75, 0.0, -1.0);
glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue_mat );
Sphere(1.0, 20, 20);
glPopMatrix();
glPopMatrix();
/* This is very important!!!
* Make sure buffered commands are finished!!!
*/
glFinish();
}
#ifdef SAVE_TARGA
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 */
}
}
}
}
#else
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);
}
}
#endif
int
main(int argc, char *argv[])
{
OSMesaContext ctx;
void *buffer;
char *filename = NULL;
if (argc < 2) {
fprintf(stderr, "Usage:\n");
fprintf(stderr, " osdemo filename [width height]\n");
return 0;
}
filename = argv[1];
if (argc == 4) {
Width = atoi(argv[2]);
Height = atoi(argv[3]);
}
/* Create an RGBA-mode context */
#if OSMESA_MAJOR_VERSION * 100 + OSMESA_MINOR_VERSION >= 305
/* specify Z, stencil, accum sizes */
ctx = OSMesaCreateContextExt( OSMESA_RGBA, 16, 0, 0, NULL );
#else
ctx = OSMesaCreateContext( OSMESA_RGBA, NULL );
#endif
if (!ctx) {
printf("OSMesaCreateContext failed!\n");
return 0;
}
/* Allocate the image buffer */
buffer = malloc( Width * Height * 4 * sizeof(GLubyte) );
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_UNSIGNED_BYTE, Width, Height )) {
printf("OSMesaMakeCurrent failed!\n");
return 0;
}
{
int z, s, a;
glGetIntegerv(GL_DEPTH_BITS, &z);
glGetIntegerv(GL_STENCIL_BITS, &s);
glGetIntegerv(GL_ACCUM_RED_BITS, &a);
printf("Depth=%d Stencil=%d Accum=%d\n", z, s, a);
}
render_image();
if (filename != NULL) {
#ifdef SAVE_TARGA
write_targa(filename, buffer, Width, Height);
#else
write_ppm(filename, 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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