erebus

annotate src/main.cc @ 2:474a0244f57d

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fixed specialization mistake fixed line endings added makefiles
author John Tsiombikas <nuclear@member.fsf.org>
date Mon, 28 Apr 2014 06:31:10 +0300
parents 4abdce1361b9
children 93894c232d65
rev   line source
nuclear@2 1 #include <stdio.h>
nuclear@2 2 #include <stdlib.h>
nuclear@2 3 #include <assert.h>
nuclear@2 4 #include "opengl.h"
nuclear@2 5
nuclear@2 6 static bool init();
nuclear@2 7 static void cleanup();
nuclear@2 8 static void resize_rtarget(int xsz, int ysz);
nuclear@2 9 static void update_rect(int x, int y, int xsz, int ysz, float *pixels);
nuclear@2 10 static void display();
nuclear@2 11 static void reshape(int x, int y);
nuclear@2 12 static void keyb(unsigned char key, int x, int y);
nuclear@2 13 static void mouse(int bn, int st, int x, int y);
nuclear@2 14 static int next_pow2(int x);
nuclear@2 15
nuclear@2 16 static int width, height, rtex_width, rtex_height;
nuclear@2 17 static unsigned int rtex;
nuclear@2 18
nuclear@2 19 int main(int argc, char **argv)
nuclear@2 20 {
nuclear@2 21 glutInitWindowSize(1024, 600);
nuclear@2 22 glutInit(&argc, argv);
nuclear@2 23 glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
nuclear@2 24 glutCreateWindow("erebus OpenGL frontend");
nuclear@2 25
nuclear@2 26 glutDisplayFunc(display);
nuclear@2 27 glutReshapeFunc(reshape);
nuclear@2 28 glutKeyboardFunc(keyb);
nuclear@2 29 glutMouseFunc(mouse);
nuclear@2 30
nuclear@2 31 if(!init()) {
nuclear@2 32 return 1;
nuclear@2 33 }
nuclear@2 34 atexit(cleanup);
nuclear@2 35
nuclear@2 36 glutMainLoop();
nuclear@2 37 }
nuclear@2 38
nuclear@2 39 static bool init()
nuclear@2 40 {
nuclear@2 41 return true;
nuclear@2 42 }
nuclear@2 43
nuclear@2 44 static void cleanup()
nuclear@2 45 {
nuclear@2 46 }
nuclear@2 47
nuclear@2 48 static void resize_rtarget(int xsz, int ysz)
nuclear@2 49 {
nuclear@2 50 static unsigned char *defpix;
nuclear@2 51
nuclear@2 52 width = xsz;
nuclear@2 53 height = ysz;
nuclear@2 54
nuclear@2 55 if(xsz <= rtex_width && ysz <= rtex_height) {
nuclear@2 56 return;
nuclear@2 57 }
nuclear@2 58 rtex_width = next_pow2(xsz);
nuclear@2 59 rtex_height = next_pow2(ysz);
nuclear@2 60
nuclear@2 61 printf("resizing framebuffer texture: %dx%d\n", rtex_width, rtex_height);
nuclear@2 62
nuclear@2 63 if(!rtex) {
nuclear@2 64 glGenTextures(1, &rtex);
nuclear@2 65 }
nuclear@2 66
nuclear@2 67 delete [] defpix;
nuclear@2 68 defpix = new unsigned char[rtex_width * rtex_height * 4];
nuclear@2 69 unsigned char *ptr = defpix;
nuclear@2 70 for(int i=0; i<rtex_height; i++) {
nuclear@2 71 for(int j=0; j<rtex_width; j++) {
nuclear@2 72 bool chess = ((i >> 4) & 1) == ((j >> 4) & 1);
nuclear@2 73
nuclear@2 74 int val = chess ? 64 : 48;
nuclear@2 75
nuclear@2 76 *ptr++ = val;
nuclear@2 77 *ptr++ = val;
nuclear@2 78 *ptr++ = val;
nuclear@2 79 *ptr++ = 255;
nuclear@2 80 }
nuclear@2 81 }
nuclear@2 82
nuclear@2 83 glBindTexture(GL_TEXTURE_2D, rtex);
nuclear@2 84 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
nuclear@2 85 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
nuclear@2 86 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F_ARB, rtex_width, rtex_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, defpix);
nuclear@2 87 }
nuclear@2 88
nuclear@2 89 static void update_rect(int x, int y, int xsz, int ysz, float *pixels)
nuclear@2 90 {
nuclear@2 91 glBindTexture(GL_TEXTURE_2D, rtex);
nuclear@2 92 glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, xsz, ysz, GL_RGBA, GL_FLOAT, pixels);
nuclear@2 93 }
nuclear@2 94
nuclear@2 95 static void display()
nuclear@2 96 {
nuclear@2 97 glBindTexture(GL_TEXTURE_2D, rtex);
nuclear@2 98 glEnable(GL_TEXTURE_2D);
nuclear@2 99
nuclear@2 100 float maxu = (float)width / (float)rtex_width;
nuclear@2 101 float maxv = (float)height / (float)rtex_height;
nuclear@2 102
nuclear@2 103 glBegin(GL_QUADS);
nuclear@2 104 glTexCoord2f(0, maxv); glVertex2f(-1, -1);
nuclear@2 105 glTexCoord2f(maxu, maxv); glVertex2f(1, -1);
nuclear@2 106 glTexCoord2f(maxu, 0); glVertex2f(1, 1);
nuclear@2 107 glTexCoord2f(0, 0); glVertex2f(-1, 1);
nuclear@2 108 glEnd();
nuclear@2 109
nuclear@2 110 glDisable(GL_TEXTURE_2D);
nuclear@2 111
nuclear@2 112 glutSwapBuffers();
nuclear@2 113 assert(glGetError() == GL_NO_ERROR);
nuclear@2 114 }
nuclear@2 115
nuclear@2 116 static void reshape(int x, int y)
nuclear@2 117 {
nuclear@2 118 glViewport(0, 0, x, y);
nuclear@2 119 resize_rtarget(x, y);
nuclear@2 120 }
nuclear@2 121
nuclear@2 122 static void keyb(unsigned char key, int x, int y)
nuclear@2 123 {
nuclear@2 124 switch(key) {
nuclear@2 125 case 27:
nuclear@2 126 exit(0);
nuclear@2 127 }
nuclear@2 128 }
nuclear@2 129
nuclear@2 130 static void mouse(int bn, int st, int x, int y)
nuclear@2 131 {
nuclear@2 132 }
nuclear@2 133
nuclear@2 134 static int next_pow2(int x)
nuclear@2 135 {
nuclear@2 136 int res = 2;
nuclear@2 137 while(res < x) {
nuclear@2 138 res <<= 1;
nuclear@2 139 }
nuclear@2 140 return res;
nuclear@2 141 }