git.mutantstargoat.com Git - meshfrac/blob - main.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <assert.h>
   4 #include "opengl.h"
   5 #include <GL/glut.h>
   6 #include <cgmath/cgmath.h>
   7 #include "cmesh.h"
   8 #include "meshgen.h"
   9 #include "sdr.h"
  10
  11 static const char *vsdr_src =
  12         "varying vec3 v_norm, v_ldir, v_vdir;\n"
  13         "void main()\n"
  14         "{\n"
  15         "       gl_Position = ftransform();\n"
  16         "       vec3 vpos = (gl_ModelViewMatrix * gl_Vertex).xyz;\n"
  17         "       v_vdir = -vpos;\n"
  18         "       v_norm = gl_NormalMatrix * gl_Normal;\n"
  19         "       v_ldir = gl_LightSource[0].position.xyz - vpos;\n"
  20         "}\n";
  21
  22 static const char *psdr_src =
  23         "varying vec3 v_norm, v_ldir, v_vdir;\n"
  24         "void main()\n"
  25         "{\n"
  26         "       vec3 n = normalize(v_norm);\n"
  27         "       vec3 v = normalize(v_vdir);\n"
  28         "       vec3 l = normalize(v_ldir);\n"
  29         "       vec3 h = normalize(v + l);\n"
  30         "       float ndotl = max(dot(n, l), 0.0);\n"
  31         "       float ndoth = max(dot(n, h), 0.0);\n"
  32         "       float spec = pow(ndoth, gl_FrontMaterial.shininess);\n"
  33         "       vec3 dcol = gl_FrontMaterial.diffuse.rgb * ndotl;\n"
  34         "       vec3 scol = gl_FrontMaterial.specular.rgb * spec;\n"
  35         "       gl_FragColor = vec4(dcol + scol, 1.0);\n"
  36         "}\n";
  37
  38 static int init(void);
  39 static void cleanup(void);
  40 static void display(void);
  41 static void reshape(int x, int y);
  42 static void keydown(unsigned char key, int x, int y);
  43 static void mouse(int bn, int st, int x, int y);
  44 static void motion(int x, int y);
  45
  46 static int win_width, win_height;
  47 static cgm_vec3 view_pos;
  48 static float view_theta, view_phi = 0.6, view_dist = 8;
  49 static float proj_mat[16], view_mat[16];
  50 static int bnstate[8];
  51 static int mx, my;
  52
  53 static struct cmesh *mesh;
  54 static unsigned int sdr;
  55
  56 int main(int argc, char **argv)
  57 {
  58         glutInit(&argc, argv);
  59         glutInitWindowSize(1280, 800);
  60         glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
  61         glutCreateWindow("meshfrac");
  62
  63         glutDisplayFunc(display);
  64         glutReshapeFunc(reshape);
  65         glutKeyboardFunc(keydown);
  66         glutMouseFunc(mouse);
  67         glutMotionFunc(motion);
  68
  69         if(init() == -1) {
  70                 return 1;
  71         }
  72         atexit(cleanup);
  73
  74         glutMainLoop();
  75         return 0;
  76 }
  77
  78 static int init(void)
  79 {
  80         unsigned int vsdr, psdr;
  81         float diffuse[] = {0.2, 0.3, 0.8, 1};
  82         float specular[] = {0.8, 0.8, 0.8, 1};
  83 #ifdef __glew_h__
  84         glewInit();
  85 #endif
  86
  87         if(!(vsdr = create_vertex_shader(vsdr_src))) {
  88                 return -1;
  89         }
  90         if(!(psdr = create_pixel_shader(psdr_src))) {
  91                 free_shader(vsdr);
  92                 return -1;
  93         }
  94         if(!(sdr = create_program_link(vsdr, psdr, 0))) {
  95                 free_shader(vsdr);
  96                 free_shader(psdr);
  97                 return -1;
  98         }
  99
 100         glEnable(GL_CULL_FACE);
 101         glEnable(GL_DEPTH_TEST);
 102         glEnable(GL_LIGHTING);
 103         glEnable(GL_LIGHT0);
 104
 105         glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, diffuse);
 106         glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);
 107         glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 60);
 108
 109         bind_program(sdr);
 110
 111         mesh = cmesh_alloc();
 112         gen_torus(mesh, 2, 0.8, 24, 12, 1, 1);
 113
 114         return 0;
 115 }
 116
 117 static void cleanup(void)
 118 {
 119         cmesh_free(mesh);
 120         free_program(sdr);
 121 }
 122
 123 static void display(void)
 124 {
 125         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 126
 127         cgm_mtranslation(view_mat, 0, 0, -view_dist);
 128         cgm_mprerotate_x(view_mat, view_phi);
 129         cgm_mprerotate_y(view_mat, view_theta);
 130         cgm_mpretranslate(view_mat, -view_pos.x, -view_pos.y, -view_pos.z);
 131         glMatrixMode(GL_MODELVIEW);
 132         glLoadMatrixf(view_mat);
 133
 134         cmesh_draw(mesh);
 135
 136         assert(glGetError() == GL_NO_ERROR);
 137         glutSwapBuffers();
 138 }
 139
 140 static void reshape(int x, int y)
 141 {
 142         win_width = x;
 143         win_height = y;
 144         glViewport(0, 0, x, y);
 145
 146         cgm_mperspective(proj_mat, cgm_deg_to_rad(50), (float)x / y, 0.5, 500.0);
 147         glMatrixMode(GL_PROJECTION);
 148         glLoadMatrixf(proj_mat);
 149 }
 150
 151 static void keydown(unsigned char key, int x, int y)
 152 {
 153         switch(key) {
 154         case 27:
 155                 exit(0);
 156         }
 157 }
 158
 159 static void mouse(int bn, int st, int x, int y)
 160 {
 161         int bidx = bn - GLUT_LEFT_BUTTON;
 162         if(bidx < 8) {
 163                 bnstate[bidx] = st == GLUT_DOWN;
 164         }
 165         mx = x;
 166         my = y;
 167 }
 168
 169 static void motion(int x, int y)
 170 {
 171         int dx = x - mx;
 172         int dy = y - my;
 173         mx = x;
 174         my = y;
 175
 176         if(!(dx | dy)) return;
 177
 178         if(bnstate[0]) {
 179                 view_theta += cgm_deg_to_rad(dx * 0.5);
 180                 view_phi += cgm_deg_to_rad(dy * 0.5);
 181                 if(view_phi < -M_PI / 2) view_phi = -M_PI / 2;
 182                 if(view_phi > M_PI / 2) view_phi = M_PI / 2;
 183                 glutPostRedisplay();
 184         }
 185         if(bnstate[1]) {
 186                 cgm_vec3 up, right;
 187
 188                 up.x = -sin(view_theta) * sin(view_phi);
 189                 up.y = -cos(view_phi);
 190                 up.z = cos(view_theta) * sin(view_phi);
 191                 right.x = cos(view_theta);
 192                 right.y = 0;
 193                 right.z = sin(view_theta);
 194
 195                 view_pos.x -= (right.x * dx + up.x * dy) * 0.01;
 196                 view_pos.y -= up.y * dy * 0.01;
 197                 view_pos.z -= (right.z * dx + up.z * dy) * 0.01;
 198                 glutPostRedisplay();
 199         }
 200         if(bnstate[2]) {
 201                 view_dist += dy * 0.1;
 202                 if(view_dist < 0) view_dist = 0;
 203                 glutPostRedisplay();
 204         }
 205 }