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