distray

annotate src/main.cc @ 0:cf494adee646

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distance field raytracer
author John Tsiombikas <nuclear@member.fsf.org>
date Fri, 25 Dec 2015 05:41:10 +0200
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nuclear@0 1 #include <stdio.h>
nuclear@0 2 #include <stdlib.h>
nuclear@0 3 #include <assert.h>
nuclear@0 4 #include <GL/glew.h>
nuclear@0 5 #include <GL/glut.h>
nuclear@0 6 #include <vmath/vmath.h>
nuclear@0 7 #include "rend.h"
nuclear@0 8
nuclear@0 9 static bool init();
nuclear@0 10 static void cleanup();
nuclear@0 11 static void display();
nuclear@0 12 static void reshape(int x, int y);
nuclear@0 13 static void keyb(unsigned char key, int x, int y);
nuclear@0 14 static void mouse(int bn, int st, int x, int y);
nuclear@0 15 static void motion(int x, int y);
nuclear@0 16 static void resize_fbtex(int xsz, int ysz);
nuclear@0 17 static void update_fbtex();
nuclear@0 18 static int next_pow2(int x);
nuclear@0 19 static float dfunc(float x, float y, float z);
nuclear@0 20
nuclear@0 21 static int pix_scale = 2;
nuclear@0 22 static int width = 640;
nuclear@0 23 static int height = 384;
nuclear@0 24 static int win_width = width * pix_scale;
nuclear@0 25 static int win_height = height * pix_scale;
nuclear@0 26
nuclear@0 27 static float *pixels;
nuclear@0 28 static unsigned int tex;
nuclear@0 29 static int tex_width, tex_height;
nuclear@0 30
nuclear@0 31 static float cam_theta, cam_phi = 25, cam_dist = 10;
nuclear@0 32
nuclear@0 33
nuclear@0 34 int main(int argc, char **argv)
nuclear@0 35 {
nuclear@0 36 glutInit(&argc, argv);
nuclear@0 37 glutInitWindowSize(win_width, win_height);
nuclear@0 38 glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
nuclear@0 39 glutCreateWindow("distance field raytracer");
nuclear@0 40
nuclear@0 41 glutDisplayFunc(display);
nuclear@0 42 glutReshapeFunc(reshape);
nuclear@0 43 glutKeyboardFunc(keyb);
nuclear@0 44 glutMouseFunc(mouse);
nuclear@0 45 glutMotionFunc(motion);
nuclear@0 46
nuclear@0 47 if(!init()) {
nuclear@0 48 return 1;
nuclear@0 49 }
nuclear@0 50 atexit(cleanup);
nuclear@0 51
nuclear@0 52 glutMainLoop();
nuclear@0 53 return 0;
nuclear@0 54 }
nuclear@0 55
nuclear@0 56 static bool init()
nuclear@0 57 {
nuclear@0 58 glewInit();
nuclear@0 59
nuclear@0 60 glEnable(GL_CULL_FACE);
nuclear@0 61
nuclear@0 62 glGenTextures(1, &tex);
nuclear@0 63 glBindTexture(GL_TEXTURE_2D, tex);
nuclear@0 64 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
nuclear@0 65 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
nuclear@0 66
nuclear@0 67 glEnable(GL_TEXTURE_2D);
nuclear@0 68
nuclear@0 69 set_distance_function(dfunc);
nuclear@0 70
nuclear@0 71 return true;
nuclear@0 72 }
nuclear@0 73
nuclear@0 74 static void cleanup()
nuclear@0 75 {
nuclear@0 76 glDeleteTextures(1, &tex);
nuclear@0 77 }
nuclear@0 78
nuclear@0 79 static void display()
nuclear@0 80 {
nuclear@0 81 Matrix4x4 cmat;
nuclear@0 82 cmat.translate(Vector3(0, 0, -cam_dist));
nuclear@0 83 cmat.rotate(Vector3(1, 0, 0), DEG_TO_RAD(cam_phi));
nuclear@0 84 cmat.rotate(Vector3(0, 1, 0), DEG_TO_RAD(cam_theta));
nuclear@0 85
nuclear@0 86 set_camera_matrix(cmat);
nuclear@0 87 render();
nuclear@0 88 update_fbtex();
nuclear@0 89
nuclear@0 90 glMatrixMode(GL_TEXTURE);
nuclear@0 91 glLoadIdentity();
nuclear@0 92 glScalef((float)tex_width / (float)width, (float)tex_height / (float)height, 1);
nuclear@0 93
nuclear@0 94 glBegin(GL_QUADS);
nuclear@0 95 glTexCoord2f(0, 0); glVertex2f(-1, -1);
nuclear@0 96 glTexCoord2f(1, 0); glVertex2f(1, -1);
nuclear@0 97 glTexCoord2f(1, 1); glVertex2f(1, 1);
nuclear@0 98 glTexCoord2f(0, 1); glVertex2f(-1, 1);
nuclear@0 99 glEnd();
nuclear@0 100
nuclear@0 101 glutSwapBuffers();
nuclear@0 102 assert(glGetError() == GL_NO_ERROR);
nuclear@0 103 }
nuclear@0 104
nuclear@0 105 static void reshape(int x, int y)
nuclear@0 106 {
nuclear@0 107 static int prev_x , prev_y;
nuclear@0 108
nuclear@0 109 glViewport(0, 0, x, y);
nuclear@0 110 resize_fbtex(x, y);
nuclear@0 111
nuclear@0 112 if(x != prev_x || y != prev_y) {
nuclear@0 113 delete [] pixels;
nuclear@0 114 pixels = new float[x * y * 4];
nuclear@0 115 set_framebuffer(x, y, pixels);
nuclear@0 116 prev_x = x;
nuclear@0 117 prev_y = y;
nuclear@0 118 }
nuclear@0 119 }
nuclear@0 120
nuclear@0 121 static void resize_fbtex(int xsz, int ysz)
nuclear@0 122 {
nuclear@0 123 int txsz = next_pow2(xsz);
nuclear@0 124 int tysz = next_pow2(ysz);
nuclear@0 125
nuclear@0 126 if(txsz > tex_width || tysz > tex_height) {
nuclear@0 127 tex_width = txsz;
nuclear@0 128 tex_height = tysz;
nuclear@0 129
nuclear@0 130 glBindTexture(GL_TEXTURE_2D, tex);
nuclear@0 131 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, txsz, tysz, 0, GL_RGBA, GL_FLOAT, 0);
nuclear@0 132 }
nuclear@0 133 }
nuclear@0 134
nuclear@0 135 static void update_fbtex()
nuclear@0 136 {
nuclear@0 137 glBindTexture(GL_TEXTURE_2D, tex);
nuclear@0 138 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GL_RGBA, GL_FLOAT, pixels);
nuclear@0 139 }
nuclear@0 140
nuclear@0 141 static int next_pow2(int x)
nuclear@0 142 {
nuclear@0 143 --x;
nuclear@0 144 x |= x >> 1;
nuclear@0 145 x |= x >> 2;
nuclear@0 146 x |= x >> 4;
nuclear@0 147 x |= x >> 8;
nuclear@0 148 x |= x >> 16;
nuclear@0 149 return x + 1;
nuclear@0 150 }
nuclear@0 151
nuclear@0 152 static float dfunc(float x, float y, float z)
nuclear@0 153 {
nuclear@0 154 return sqrt(x*x + y*y + z*z) - 1.0;
nuclear@0 155 }
nuclear@0 156
nuclear@0 157 static void keyb(unsigned char key, int x, int y)
nuclear@0 158 {
nuclear@0 159 switch(key) {
nuclear@0 160 case 27:
nuclear@0 161 exit(0);
nuclear@0 162 }
nuclear@0 163 }
nuclear@0 164
nuclear@0 165 static int prev_x, prev_y;
nuclear@0 166 static bool bnstate[8];
nuclear@0 167
nuclear@0 168 static void mouse(int bn, int st, int x, int y)
nuclear@0 169 {
nuclear@0 170 bnstate[bn - GLUT_LEFT_BUTTON] = st == GLUT_DOWN;
nuclear@0 171 prev_x = x;
nuclear@0 172 prev_y = y;
nuclear@0 173 }
nuclear@0 174
nuclear@0 175 static void motion(int x, int y)
nuclear@0 176 {
nuclear@0 177 int dx = x - prev_x;
nuclear@0 178 int dy = y - prev_y;
nuclear@0 179 prev_x = x;
nuclear@0 180 prev_y = y;
nuclear@0 181
nuclear@0 182 if(!dx && !dy) return;
nuclear@0 183
nuclear@0 184 if(bnstate[0]) {
nuclear@0 185 cam_theta -= dx * 0.5;
nuclear@0 186 cam_phi -= dy * 0.5;
nuclear@0 187
nuclear@0 188 if(cam_phi < -90) cam_phi = -90;
nuclear@0 189 if(cam_phi > 90) cam_phi = 90;
nuclear@0 190 glutPostRedisplay();
nuclear@0 191 }
nuclear@0 192 if(bnstate[2]) {
nuclear@0 193 cam_dist += dy * 0.1;
nuclear@0 194 if(cam_dist < 0.0) cam_dist = 0.0;
nuclear@0 195 glutPostRedisplay();
nuclear@0 196 }
nuclear@0 197 }