/* * 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/glu.h" #define SAVE_TARGA #define WIDTH 400 #define 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[]) { void *buffer; int i; char *filename = NULL; /* Create an RGBA-mode context */ #if OSMESA_MAJOR_VERSION * 100 + OSMESA_MINOR_VERSION >= 305 /* specify Z, stencil, accum sizes */ OSMesaContext ctx = OSMesaCreateContextExt( OSMESA_RGBA, 16, 0, 0, NULL ); #else OSMesaContext ctx = OSMesaCreateContext( OSMESA_RGBA, NULL ); #endif if (!ctx) { printf("OSMesaCreateContext failed!\n"); return 0; } for (i = 1; i < argc; i++) { if (argv[i][0] != '-') filename = argv[i]; } /* 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; }