/* * Demo of off-screen Mesa rendering with 16-bit color channels. * This requires the libOSMesa16.so library. * * Compile with something like this: * * gcc osdemo16.c -I../include -L../lib -lOSMesa16 -lm -o osdemo16 */ #include #include #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 GLushort *buffer, int width, int height) { FILE *f = fopen( filename, "w" ); if (f) { int i, x, y; const GLushort *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> 8, f); /* write blue */ fputc(ptr[i+1] >> 8, f); /* write green */ fputc(ptr[i] >> 8, 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=0; y--) { for (x=0; x= 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 = malloc( WIDTH * HEIGHT * 4 * sizeof(GLushort)); 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_SHORT, 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; }