git.mutantstargoat.com Git - erebus2020/blob - xerebus/src/main.c

   1 #include <stdio.h>
   2 #include "opengl.h"
   3 #include "miniglut.h"
   4 #include "erebus.h"
   5 #include "sdr.h"
   6
   7 static void display(void);
   8 static void reshape(int x, int y);
   9 static void keyb(unsigned char key, int x, int y);
  10 static void mouse(int bn, int st, int x, int y);
  11 static void motion(int x, int y);
  12
  13 static int win_width, win_height;
  14 static float win_aspect;
  15 static int reshape_pending;
  16
  17 static struct erb_rend *erb;
  18
  19 static int mouse_x, mouse_y;
  20 static int drag_x, drag_y;
  21 static int drag;
  22
  23 static float disp_gamma = 2.2f;
  24
  25 static unsigned int fbtex;
  26 static unsigned int sdr;
  27
  28 static const char *vs_src =
  29         "void main()\n"
  30         "{\n"
  31         "       gl_Position = ftransform();\n"
  32         "       gl_TexCoord[0] = gl_MultiTexCoord0;\n"
  33         "}\n";
  34
  35 static const char *ps_src =
  36         "uniform sampler2D tex;\n"
  37         "uniform float inv_gamma;\n"
  38         "\n"
  39         "void main()\n"
  40         "{\n"
  41         "       vec4 texel = texture2D(tex, gl_TexCoord[0].st);\n"
  42         "       gl_FragColor.rgb = pow(texel.xyz / texel.w, vec3(inv_gamma));\n"
  43         "       gl_FragColor.a = 1.0;\n"
  44         "}\n";
  45
  46
  47 int main(int argc, char **argv)
  48 {
  49         unsigned int vs, ps;
  50
  51         glutInit(&argc, argv);
  52         glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
  53         glutInitWindowSize(1280, 800);
  54         glutCreateWindow("X erebus");
  55
  56         glutDisplayFunc(display);
  57         glutReshapeFunc(reshape);
  58         glutKeyboardFunc(keyb);
  59         glutMouseFunc(mouse);
  60         glutMotionFunc(motion);
  61
  62         if(!(vs = create_vertex_shader(vs_src))) {
  63                 return 1;
  64         }
  65         if(!(ps = create_pixel_shader(ps_src))) {
  66                 return 1;
  67         }
  68         if(!(sdr = create_program_link(vs, ps, 0))) {
  69                 return 1;
  70         }
  71         set_uniform_float(sdr, "inv_gamma", 1.0f / disp_gamma);
  72
  73         if(!(erb = erb_create())) {
  74                 return 1;
  75         }
  76         reshape_pending = 1;
  77
  78         glGenTextures(1, &fbtex);
  79         glBindTexture(GL_TEXTURE_2D, fbtex);
  80         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  81         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  82
  83         glutMainLoop();
  84         erb_destroy(erb);
  85         return 0;
  86 }
  87
  88 static void display(void)
  89 {
  90         if(reshape_pending) {
  91                 reshape_pending = 0;
  92
  93                 erb_allocframe(erb, win_width, win_height);
  94                 erb_begin(erb);
  95
  96                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, win_width, win_height, 0,
  97                                 GL_RGBA, GL_FLOAT, erb_getframe(erb));
  98         } else {
  99                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, win_width, win_height,
 100                                 GL_RGBA, GL_FLOAT, erb_getframe(erb));
 101         }
 102         /* TODO: continue with getting notified when a block is done rendering */
 103
 104
 105         glClear(GL_COLOR_BUFFER_BIT);
 106
 107         glUseProgram(sdr);
 108
 109         glBegin(GL_QUADS);
 110         glColor3f(1, 1, 1);
 111         glTexCoord2f(0, 0);
 112         glVertex2f(0, 0);
 113         glTexCoord2f(1, 0);
 114         glVertex2f(win_width, 0);
 115         glTexCoord2f(1, 1);
 116         glVertex2f(win_width, win_height);
 117         glTexCoord2f(0, 1);
 118         glVertex2f(0, win_height);
 119         glEnd();
 120
 121         if(drag) {
 122                 glUseProgram(0);
 123
 124                 glEnable(GL_LOGIC_OP);
 125                 glLogicOp(GL_XOR);
 126
 127                 glBegin(GL_LINE_LOOP);
 128                 glColor3f(1, 1, 1);
 129                 glVertex2f(drag_x, drag_y);
 130                 glVertex2f(mouse_x, drag_y);
 131                 glVertex2f(mouse_x, mouse_y);
 132                 glVertex2f(drag_x, mouse_y);
 133                 glEnd();
 134
 135                 glDisable(GL_LOGIC_OP);
 136         }
 137
 138         glutSwapBuffers();
 139 }
 140
 141 static void reshape(int x, int y)
 142 {
 143         win_width = x;
 144         win_height = y;
 145         win_aspect = (float)x / (float)y;
 146
 147         glViewport(0, 0, x, y);
 148
 149         glMatrixMode(GL_PROJECTION);
 150         glLoadIdentity();
 151         glOrtho(0, x, y, 0, -1, 1);
 152
 153         reshape_pending = 1;
 154         glutPostRedisplay();
 155 }
 156
 157 static void keyb(unsigned char key, int x, int y)
 158 {
 159         if(key == 27) {
 160                 glutExit();
 161         }
 162         glutPostRedisplay();
 163 }
 164
 165 static void mouse(int bn, int st, int x, int y)
 166 {
 167         int rect[4];
 168
 169         mouse_x = x;
 170         mouse_y = y;
 171
 172         if(bn == 0) {
 173                 if(st == GLUT_DOWN) {
 174                         drag = 1;
 175                         drag_x = x;
 176                         drag_y = y;
 177                 } else {
 178                         drag = 0;
 179
 180                         rect[0] = x < drag_x ? x : drag_x;
 181                         rect[1] = y < drag_y ? y : drag_y;
 182                         rect[2] = abs(x - drag_x);
 183                         rect[3] = abs(y - drag_y);
 184
 185                         erb_queue_block(erb, rect[0], rect[1], rect[2], rect[3]);
 186                         printf("rect: %d,%d %dx%d\n", rect[0], rect[1], rect[2], rect[3]);
 187                 }
 188
 189                 glutPostRedisplay();
 190         }
 191 }
 192
 193 static void motion(int x, int y)
 194 {
 195         mouse_x = x;
 196         mouse_y = y;
 197
 198         glutPostRedisplay();
 199 }