| |
| /* |
| * glDrawPixels demo/test/benchmark |
| * |
| * Brian Paul September 25, 1997 This file is in the public domain. |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <math.h> |
| #include <string.h> |
| #include <GL/glut.h> |
| |
| #include "readtex.h" |
| |
| #define IMAGE_FILE "../images/girl.rgb" |
| |
| static int ImgWidth, ImgHeight; |
| static GLenum ImgFormat; |
| static GLubyte *Image = NULL; |
| |
| static int Xpos, Ypos; |
| static int SkipPixels, SkipRows; |
| static int DrawWidth, DrawHeight; |
| static int Scissor = 0; |
| static int Fog = 0; |
| static GLfloat Zpos = -1.0; |
| static float Xzoom, Yzoom; |
| static GLboolean DrawFront = GL_FALSE; |
| static GLboolean Dither = GL_TRUE; |
| static int win = 0; |
| |
| |
| static void Reset( void ) |
| { |
| Xpos = Ypos = 20; |
| DrawWidth = ImgWidth; |
| DrawHeight = ImgHeight; |
| SkipPixels = SkipRows = 0; |
| Scissor = 0; |
| Fog = 0; |
| Zpos = -1.0; |
| Xzoom = Yzoom = 1.0; |
| } |
| |
| |
| static void Display( void ) |
| { |
| glClear( GL_COLOR_BUFFER_BIT ); |
| |
| #if 0 |
| glRasterPos2i(Xpos, Ypos); |
| #else |
| /* This allows negative raster positions: */ |
| glRasterPos3f(0, 0, Zpos); |
| glBitmap(0, 0, 0, 0, Xpos, Ypos, NULL); |
| #endif |
| |
| glPixelStorei(GL_UNPACK_SKIP_PIXELS, SkipPixels); |
| glPixelStorei(GL_UNPACK_SKIP_ROWS, SkipRows); |
| |
| glPixelZoom( Xzoom, Yzoom ); |
| |
| if (Scissor) |
| glEnable(GL_SCISSOR_TEST); |
| |
| if (Fog) |
| glEnable(GL_FOG); |
| |
| glDrawPixels(DrawWidth, DrawHeight, ImgFormat, GL_UNSIGNED_BYTE, Image); |
| |
| glDisable(GL_SCISSOR_TEST); |
| glDisable(GL_FOG); |
| |
| if (DrawFront) |
| glFinish(); |
| else |
| glutSwapBuffers(); |
| } |
| |
| |
| static void Benchmark( void ) |
| { |
| int startTime, endTime; |
| int draws = 500; |
| double seconds, pixelsPerSecond; |
| |
| printf("Benchmarking...\n"); |
| /* GL set-up */ |
| glPixelStorei(GL_UNPACK_SKIP_PIXELS, SkipPixels); |
| glPixelStorei(GL_UNPACK_SKIP_ROWS, SkipRows); |
| glPixelZoom( Xzoom, Yzoom ); |
| if (Scissor) |
| glEnable(GL_SCISSOR_TEST); |
| if (Fog) |
| glEnable(GL_FOG); |
| |
| if (DrawFront) |
| glDrawBuffer(GL_FRONT); |
| else |
| glDrawBuffer(GL_BACK); |
| |
| /* Run timing test */ |
| draws = 0; |
| startTime = glutGet(GLUT_ELAPSED_TIME); |
| do { |
| glDrawPixels(DrawWidth, DrawHeight, ImgFormat, GL_UNSIGNED_BYTE, Image); |
| draws++; |
| endTime = glutGet(GLUT_ELAPSED_TIME); |
| } while (endTime - startTime < 4000); /* 4 seconds */ |
| |
| /* GL clean-up */ |
| glDisable(GL_SCISSOR_TEST); |
| glDisable(GL_FOG); |
| |
| /* Results */ |
| seconds = (double) (endTime - startTime) / 1000.0; |
| pixelsPerSecond = draws * DrawWidth * DrawHeight / seconds; |
| printf("Result: %d draws in %f seconds = %f pixels/sec\n", |
| draws, seconds, pixelsPerSecond); |
| } |
| |
| |
| static void Reshape( int width, int height ) |
| { |
| glViewport( 0, 0, width, height ); |
| glMatrixMode( GL_PROJECTION ); |
| glLoadIdentity(); |
| glOrtho( 0.0, width, 0.0, height, 0.0, 2.0 ); |
| glMatrixMode( GL_MODELVIEW ); |
| glLoadIdentity(); |
| |
| glScissor(width/4, height/4, width/2, height/2); |
| } |
| |
| |
| static void Key( unsigned char key, int x, int y ) |
| { |
| (void) x; |
| (void) y; |
| switch (key) { |
| case ' ': |
| Reset(); |
| break; |
| case 'd': |
| Dither = !Dither; |
| if (Dither) |
| glEnable(GL_DITHER); |
| else |
| glDisable(GL_DITHER); |
| break; |
| case 'w': |
| if (DrawWidth > 0) |
| DrawWidth--; |
| break; |
| case 'W': |
| DrawWidth++; |
| break; |
| case 'h': |
| if (DrawHeight > 0) |
| DrawHeight--; |
| break; |
| case 'H': |
| DrawHeight++; |
| break; |
| case 'p': |
| if (SkipPixels > 0) |
| SkipPixels--; |
| break; |
| case 'P': |
| SkipPixels++; |
| break; |
| case 'r': |
| if (SkipRows > 0) |
| SkipRows--; |
| break; |
| case 'R': |
| SkipRows++; |
| break; |
| case 's': |
| Scissor = !Scissor; |
| break; |
| case 'x': |
| Xzoom -= 0.1; |
| break; |
| case 'X': |
| Xzoom += 0.1; |
| break; |
| case 'y': |
| Yzoom -= 0.1; |
| break; |
| case 'Y': |
| Yzoom += 0.1; |
| break; |
| case 'z': |
| Zpos -= 0.1; |
| printf("RasterPos Z = %g\n", Zpos); |
| break; |
| case 'Z': |
| Zpos += 0.1; |
| printf("RasterPos Z = %g\n", Zpos); |
| break; |
| case 'b': |
| Benchmark(); |
| break; |
| case 'F': |
| Fog = !Fog; |
| printf("Fog %d\n", Fog); |
| break; |
| case 'f': |
| DrawFront = !DrawFront; |
| if (DrawFront) |
| glDrawBuffer(GL_FRONT); |
| else |
| glDrawBuffer(GL_BACK); |
| printf("glDrawBuffer(%s)\n", DrawFront ? "GL_FRONT" : "GL_BACK"); |
| break; |
| case 27: |
| glutDestroyWindow(win); |
| exit(0); |
| break; |
| } |
| glutPostRedisplay(); |
| } |
| |
| |
| static void SpecialKey( int key, int x, int y ) |
| { |
| (void) x; |
| (void) y; |
| switch (key) { |
| case GLUT_KEY_UP: |
| Ypos += 1; |
| break; |
| case GLUT_KEY_DOWN: |
| Ypos -= 1; |
| break; |
| case GLUT_KEY_LEFT: |
| Xpos -= 1; |
| break; |
| case GLUT_KEY_RIGHT: |
| Xpos += 1; |
| break; |
| } |
| glutPostRedisplay(); |
| } |
| |
| |
| static void Init( GLboolean ciMode, const char *filename ) |
| { |
| static const GLfloat fogColor[4] = {0, 1, 0, 0}; |
| |
| printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION)); |
| printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); |
| |
| Image = LoadRGBImage( filename, &ImgWidth, &ImgHeight, &ImgFormat ); |
| if (!Image) { |
| printf("Couldn't read %s\n", filename); |
| exit(0); |
| } |
| |
| if (ciMode) { |
| /* Convert RGB image to grayscale */ |
| GLubyte *indexImage = (GLubyte *) malloc( ImgWidth * ImgHeight ); |
| GLint i; |
| for (i=0; i<ImgWidth*ImgHeight; i++) { |
| int gray = Image[i*3] + Image[i*3+1] + Image[i*3+2]; |
| indexImage[i] = gray / 3; |
| } |
| free(Image); |
| Image = indexImage; |
| ImgFormat = GL_COLOR_INDEX; |
| |
| for (i=0;i<255;i++) { |
| float g = i / 255.0; |
| glutSetColor(i, g, g, g); |
| } |
| } |
| |
| printf("Loaded %d by %d image\n", ImgWidth, ImgHeight ); |
| |
| glPixelStorei(GL_UNPACK_ALIGNMENT, 1); |
| glPixelStorei(GL_UNPACK_ROW_LENGTH, ImgWidth); |
| |
| glFogi(GL_FOG_MODE, GL_LINEAR); |
| glFogf(GL_FOG_START, 0); |
| glFogf(GL_FOG_END, 2); |
| glFogfv(GL_FOG_COLOR, fogColor); |
| |
| Reset(); |
| } |
| |
| |
| static void Usage(void) |
| { |
| printf("Keys:\n"); |
| printf(" SPACE Reset Parameters\n"); |
| printf(" Up/Down Move image up/down\n"); |
| printf(" Left/Right Move image left/right\n"); |
| printf(" x Decrease X-axis PixelZoom\n"); |
| printf(" X Increase X-axis PixelZoom\n"); |
| printf(" y Decrease Y-axis PixelZoom\n"); |
| printf(" Y Increase Y-axis PixelZoom\n"); |
| printf(" w Decrease glDrawPixels width*\n"); |
| printf(" W Increase glDrawPixels width*\n"); |
| printf(" h Decrease glDrawPixels height*\n"); |
| printf(" H Increase glDrawPixels height*\n"); |
| printf(" p Decrease GL_UNPACK_SKIP_PIXELS*\n"); |
| printf(" P Increase GL_UNPACK_SKIP_PIXELS*\n"); |
| printf(" r Decrease GL_UNPACK_SKIP_ROWS*\n"); |
| printf(" R Increase GL_UNPACK_SKIP_ROWS*\n"); |
| printf(" s Toggle GL_SCISSOR_TEST\n"); |
| printf(" F Toggle GL_FOG\n"); |
| printf(" z Decrease RasterPos Z\n"); |
| printf(" Z Increase RasterPos Z\n"); |
| |
| printf(" f Toggle front/back buffer drawing\n"); |
| printf(" b Benchmark test\n"); |
| printf(" ESC Exit\n"); |
| printf("* Warning: no limits are imposed on these parameters so it's\n"); |
| printf(" possible to cause a segfault if you go too far.\n"); |
| } |
| |
| |
| int main( int argc, char *argv[] ) |
| { |
| GLboolean ciMode = GL_FALSE; |
| const char *filename = IMAGE_FILE; |
| int i = 1; |
| |
| glutInitWindowSize( 500, 400 ); |
| glutInit( &argc, argv ); |
| |
| if (argc > i && strcmp(argv[i], "-ci")==0) { |
| ciMode = GL_TRUE; |
| i++; |
| } |
| if (argc > i) { |
| filename = argv[i]; |
| } |
| |
| if (ciMode) |
| glutInitDisplayMode( GLUT_INDEX | GLUT_DOUBLE ); |
| else |
| glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE); |
| |
| win = glutCreateWindow(argv[0]); |
| |
| Init(ciMode, filename); |
| Usage(); |
| |
| glutReshapeFunc( Reshape ); |
| glutKeyboardFunc( Key ); |
| glutSpecialFunc( SpecialKey ); |
| glutDisplayFunc( Display ); |
| |
| glutMainLoop(); |
| return 0; |
| } |