317 lines
8.1 KiB
C
317 lines
8.1 KiB
C
/*
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* Demo of off-screen Mesa rendering
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*
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* See Mesa/include/GL/osmesa.h for documentation of the OSMesa functions.
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*
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* If you want to render BIG images you'll probably have to increase
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* MAX_WIDTH and MAX_HEIGHT in src/config.h.
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*
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* This program is in the public domain.
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*
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* Brian Paul
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*
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* PPM output provided by Joerg Schmalzl.
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* ASCII PPM output added by Brian Paul.
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*
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* Usage: osdemo [filename]
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*/
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#include <math.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "GL/osmesa.h"
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#include "GL/glu.h"
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#define SAVE_TARGA
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#define WIDTH 400
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#define HEIGHT 400
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static void
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Sphere(float radius, int slices, int stacks)
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{
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GLUquadric *q = gluNewQuadric();
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gluQuadricNormals(q, GLU_SMOOTH);
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gluSphere(q, radius, slices, stacks);
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gluDeleteQuadric(q);
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}
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static void
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Cone(float base, float height, int slices, int stacks)
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{
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GLUquadric *q = gluNewQuadric();
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gluQuadricDrawStyle(q, GLU_FILL);
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gluQuadricNormals(q, GLU_SMOOTH);
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gluCylinder(q, base, 0.0, height, slices, stacks);
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gluDeleteQuadric(q);
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}
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static void
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Torus(float innerRadius, float outerRadius, int sides, int rings)
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{
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/* from GLUT... */
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int i, j;
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GLfloat theta, phi, theta1;
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GLfloat cosTheta, sinTheta;
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GLfloat cosTheta1, sinTheta1;
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const GLfloat ringDelta = 2.0 * M_PI / rings;
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const GLfloat sideDelta = 2.0 * M_PI / sides;
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theta = 0.0;
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cosTheta = 1.0;
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sinTheta = 0.0;
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for (i = rings - 1; i >= 0; i--) {
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theta1 = theta + ringDelta;
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cosTheta1 = cos(theta1);
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sinTheta1 = sin(theta1);
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glBegin(GL_QUAD_STRIP);
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phi = 0.0;
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for (j = sides; j >= 0; j--) {
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GLfloat cosPhi, sinPhi, dist;
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phi += sideDelta;
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cosPhi = cos(phi);
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sinPhi = sin(phi);
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dist = outerRadius + innerRadius * cosPhi;
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glNormal3f(cosTheta1 * cosPhi, -sinTheta1 * cosPhi, sinPhi);
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glVertex3f(cosTheta1 * dist, -sinTheta1 * dist, innerRadius * sinPhi);
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glNormal3f(cosTheta * cosPhi, -sinTheta * cosPhi, sinPhi);
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glVertex3f(cosTheta * dist, -sinTheta * dist, innerRadius * sinPhi);
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}
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glEnd();
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theta = theta1;
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cosTheta = cosTheta1;
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sinTheta = sinTheta1;
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}
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}
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static void
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render_image(void)
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{
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GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
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GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
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GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
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GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
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GLfloat red_mat[] = { 1.0, 0.2, 0.2, 1.0 };
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GLfloat green_mat[] = { 0.2, 1.0, 0.2, 1.0 };
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GLfloat blue_mat[] = { 0.2, 0.2, 1.0, 1.0 };
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glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
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glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
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glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
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glLightfv(GL_LIGHT0, GL_POSITION, light_position);
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glEnable(GL_LIGHTING);
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glEnable(GL_LIGHT0);
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glEnable(GL_DEPTH_TEST);
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glMatrixMode(GL_PROJECTION);
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glLoadIdentity();
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glOrtho(-2.5, 2.5, -2.5, 2.5, -10.0, 10.0);
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glMatrixMode(GL_MODELVIEW);
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glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
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glPushMatrix();
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glRotatef(20.0, 1.0, 0.0, 0.0);
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glPushMatrix();
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glTranslatef(-0.75, 0.5, 0.0);
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glRotatef(90.0, 1.0, 0.0, 0.0);
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glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red_mat );
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Torus(0.275, 0.85, 20, 20);
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glPopMatrix();
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glPushMatrix();
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glTranslatef(-0.75, -0.5, 0.0);
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glRotatef(270.0, 1.0, 0.0, 0.0);
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glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, green_mat );
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Cone(1.0, 2.0, 16, 1);
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glPopMatrix();
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glPushMatrix();
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glTranslatef(0.75, 0.0, -1.0);
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glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue_mat );
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Sphere(1.0, 20, 20);
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glPopMatrix();
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glPopMatrix();
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/* This is very important!!!
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* Make sure buffered commands are finished!!!
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*/
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glFinish();
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}
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#ifdef SAVE_TARGA
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static void
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write_targa(const char *filename, const GLubyte *buffer, int width, int height)
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{
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FILE *f = fopen( filename, "w" );
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if (f) {
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int i, x, y;
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const GLubyte *ptr = buffer;
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printf ("osdemo, writing tga file \n");
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fputc (0x00, f); /* ID Length, 0 => No ID */
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fputc (0x00, f); /* Color Map Type, 0 => No color map included */
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fputc (0x02, f); /* Image Type, 2 => Uncompressed, True-color Image */
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fputc (0x00, f); /* Next five bytes are about the color map entries */
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fputc (0x00, f); /* 2 bytes Index, 2 bytes length, 1 byte size */
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fputc (0x00, f);
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fputc (0x00, f);
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fputc (0x00, f);
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fputc (0x00, f); /* X-origin of Image */
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fputc (0x00, f);
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fputc (0x00, f); /* Y-origin of Image */
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fputc (0x00, f);
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fputc (WIDTH & 0xff, f); /* Image Width */
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fputc ((WIDTH>>8) & 0xff, f);
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fputc (HEIGHT & 0xff, f); /* Image Height */
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fputc ((HEIGHT>>8) & 0xff, f);
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fputc (0x18, f); /* Pixel Depth, 0x18 => 24 Bits */
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fputc (0x20, f); /* Image Descriptor */
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fclose(f);
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f = fopen( filename, "ab" ); /* reopen in binary append mode */
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for (y=height-1; y>=0; y--) {
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for (x=0; x<width; x++) {
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i = (y*width + x) * 4;
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fputc(ptr[i+2], f); /* write blue */
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fputc(ptr[i+1], f); /* write green */
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fputc(ptr[i], f); /* write red */
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}
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}
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}
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}
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#else
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static void
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write_ppm(const char *filename, const GLubyte *buffer, int width, int height)
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{
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const int binary = 0;
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FILE *f = fopen( filename, "w" );
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if (f) {
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int i, x, y;
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const GLubyte *ptr = buffer;
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if (binary) {
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fprintf(f,"P6\n");
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fprintf(f,"# ppm-file created by osdemo.c\n");
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fprintf(f,"%i %i\n", width,height);
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fprintf(f,"255\n");
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fclose(f);
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f = fopen( filename, "ab" ); /* reopen in binary append mode */
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for (y=height-1; y>=0; y--) {
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for (x=0; x<width; x++) {
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i = (y*width + x) * 4;
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fputc(ptr[i], f); /* write red */
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fputc(ptr[i+1], f); /* write green */
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fputc(ptr[i+2], f); /* write blue */
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}
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}
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}
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else {
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/*ASCII*/
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int counter = 0;
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fprintf(f,"P3\n");
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fprintf(f,"# ascii ppm file created by osdemo.c\n");
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fprintf(f,"%i %i\n", width, height);
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fprintf(f,"255\n");
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for (y=height-1; y>=0; y--) {
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for (x=0; x<width; x++) {
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i = (y*width + x) * 4;
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fprintf(f, " %3d %3d %3d", ptr[i], ptr[i+1], ptr[i+2]);
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counter++;
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if (counter % 5 == 0)
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fprintf(f, "\n");
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}
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}
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}
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fclose(f);
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}
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}
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#endif
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int
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main(int argc, char *argv[])
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{
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void *buffer;
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int i;
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char *filename = NULL;
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/* Create an RGBA-mode context */
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#if OSMESA_MAJOR_VERSION * 100 + OSMESA_MINOR_VERSION >= 305
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/* specify Z, stencil, accum sizes */
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OSMesaContext ctx = OSMesaCreateContextExt( OSMESA_RGBA, 16, 0, 0, NULL );
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#else
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OSMesaContext ctx = OSMesaCreateContext( OSMESA_RGBA, NULL );
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#endif
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if (!ctx) {
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printf("OSMesaCreateContext failed!\n");
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return 0;
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}
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for (i = 1; i < argc; i++) {
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if (argv[i][0] != '-')
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filename = argv[i];
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}
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/* Allocate the image buffer */
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buffer = malloc( WIDTH * HEIGHT * 4 * sizeof(GLubyte) );
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if (!buffer) {
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printf("Alloc image buffer failed!\n");
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return 0;
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}
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/* Bind the buffer to the context and make it current */
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if (!OSMesaMakeCurrent( ctx, buffer, GL_UNSIGNED_BYTE, WIDTH, HEIGHT )) {
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printf("OSMesaMakeCurrent failed!\n");
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return 0;
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}
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{
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int z, s, a;
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glGetIntegerv(GL_DEPTH_BITS, &z);
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glGetIntegerv(GL_STENCIL_BITS, &s);
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glGetIntegerv(GL_ACCUM_RED_BITS, &a);
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printf("Depth=%d Stencil=%d Accum=%d\n", z, s, a);
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}
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render_image();
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if (filename != NULL) {
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#ifdef SAVE_TARGA
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write_targa(filename, buffer, WIDTH, HEIGHT);
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#else
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write_ppm(filename, buffer, WIDTH, HEIGHT);
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#endif
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}
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else {
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printf("Specify a filename if you want to make an image file\n");
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}
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printf("all done\n");
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/* free the image buffer */
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free( buffer );
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/* destroy the context */
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OSMesaDestroyContext( ctx );
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return 0;
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}
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