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

   1 #include <stdio.h>
   2 #include <string.h>
   3 #include <errno.h>
   4 #include "opengl.h"
   5 #include <GL/freeglut.h>
   6 #include "erebus.h"
   7 #include "sdr.h"
   8
   9 #ifdef __unix__
  10 #include <unistd.h>
  11 #include <sys/select.h>
  12 #include <X11/Xlib.h>
  13 #include <GL/glx.h>
  14
  15 static Display *dpy;
  16 static int pfd[2];
  17 #endif
  18
  19 #define post_redisplay()  do { glutPostRedisplay(); redisp_pending = 1; } while(0)
  20
  21 static void jobdone(unsigned int job, struct erb_rect *rect, void *cls);
  22 static void display(void);
  23 static void reshape(int x, int y);
  24 static void keyb(unsigned char key, int x, int y);
  25 static void mouse(int bn, int st, int x, int y);
  26 static void motion(int x, int y);
  27
  28 static void dummy_idle(void) {}
  29
  30 static int win_width, win_height;
  31 static float win_aspect;
  32 static int reshape_pending, redisp_pending;
  33 static int quit;
  34
  35 static struct erb_rend *erb;
  36
  37 static int mouse_x, mouse_y;
  38 static int drag_x, drag_y;
  39 static int drag;
  40
  41 static float disp_gamma = 2.2f;
  42
  43 static unsigned int fbtex;
  44 static unsigned int sdr;
  45
  46 static const char *vs_src =
  47         "void main()\n"
  48         "{\n"
  49         "       gl_Position = ftransform();\n"
  50         "       gl_TexCoord[0] = gl_MultiTexCoord0;\n"
  51         "}\n";
  52
  53 static const char *ps_src =
  54         "uniform sampler2D tex;\n"
  55         "uniform float inv_gamma;\n"
  56         "\n"
  57         "void main()\n"
  58         "{\n"
  59         "       vec4 texel = texture2D(tex, gl_TexCoord[0].st);\n"
  60         "       gl_FragColor.rgb = pow(texel.xyz / texel.w, vec3(inv_gamma));\n"
  61         "       gl_FragColor.a = 1.0;\n"
  62         "}\n";
  63
  64
  65 int main(int argc, char **argv)
  66 {
  67         unsigned int vs, ps;
  68
  69 #ifdef __unix__
  70         int xfd, maxfd;
  71
  72         pipe(pfd);
  73 #endif
  74
  75         glutInit(&argc, argv);
  76         glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
  77         glutInitWindowSize(1280, 800);
  78         glutCreateWindow("X erebus");
  79
  80         glutDisplayFunc(display);
  81         glutIdleFunc(dummy_idle);       /* we want to be blocking in select, not in glutMainLoopEvent */
  82         glutReshapeFunc(reshape);
  83         glutKeyboardFunc(keyb);
  84         glutMouseFunc(mouse);
  85         glutMotionFunc(motion);
  86
  87         if(!(vs = create_vertex_shader(vs_src))) {
  88                 return 1;
  89         }
  90         if(!(ps = create_pixel_shader(ps_src))) {
  91                 return 1;
  92         }
  93         if(!(sdr = create_program_link(vs, ps, 0))) {
  94                 return 1;
  95         }
  96         set_uniform_float(sdr, "inv_gamma", 1.0f / disp_gamma);
  97
  98         if(!(erb = erb_create())) {
  99                 return 1;
 100         }
 101         erb_set_done_callback(erb, jobdone, 0);
 102
 103         reshape_pending = redisp_pending = 1;
 104
 105         glGenTextures(1, &fbtex);
 106         glBindTexture(GL_TEXTURE_2D, fbtex);
 107         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 108         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 109
 110 #ifdef __unix__
 111         dpy = glXGetCurrentDisplay();
 112         xfd = ConnectionNumber(dpy);
 113         maxfd = xfd > pfd[0] ? xfd : pfd[0];
 114
 115         while(!quit) {
 116                 struct timeval tv = {0, 0};
 117                 fd_set rdset;
 118
 119                 FD_ZERO(&rdset);
 120                 FD_SET(xfd, &rdset);
 121                 FD_SET(pfd[0], &rdset);
 122
 123                 if(select(maxfd + 1, &rdset, 0, 0, redisp_pending ? &tv : 0) == -1) {
 124                         if(errno == EINTR) continue;
 125                         fprintf(stderr, "select failed: %s\n", strerror(errno));
 126                         break;
 127                 }
 128
 129                 if(FD_ISSET(pfd[0], &rdset)) {
 130                         struct erb_rect rect;
 131                         read(pfd[0], &rect, sizeof rect);
 132                         glTexSubImage2D(GL_TEXTURE_2D, 0, rect.x, rect.y, rect.w, rect.h,
 133                                         GL_RGBA, GL_FLOAT, erb_getframe(erb) + (rect.y * win_width + rect.x) * 4);
 134                         post_redisplay();
 135                 }
 136
 137                 if(FD_ISSET(xfd, &rdset) || redisp_pending) {
 138                         redisp_pending = 0;
 139                         glutMainLoopEvent();
 140                 }
 141         }
 142 #endif  /* __unix__ */
 143
 144         erb_destroy(erb);
 145         return 0;
 146 }
 147
 148 static void jobdone(unsigned int job, struct erb_rect *rect, void *cls)
 149 {
 150         write(pfd[1], rect, sizeof *rect);
 151 }
 152
 153 static void display(void)
 154 {
 155         if(reshape_pending) {
 156                 reshape_pending = 0;
 157
 158                 erb_allocframe(erb, win_width, win_height);
 159                 erb_begin(erb);
 160
 161                 glPixelStorei(GL_UNPACK_ROW_LENGTH, win_width);
 162
 163                 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, win_width, win_height, 0,
 164                                 GL_RGBA, GL_FLOAT, erb_getframe(erb));
 165         }
 166
 167         glClear(GL_COLOR_BUFFER_BIT);
 168
 169         glUseProgram(sdr);
 170
 171         glBegin(GL_QUADS);
 172         glColor3f(1, 1, 1);
 173         glTexCoord2f(0, 0);
 174         glVertex2f(0, 0);
 175         glTexCoord2f(1, 0);
 176         glVertex2f(win_width, 0);
 177         glTexCoord2f(1, 1);
 178         glVertex2f(win_width, win_height);
 179         glTexCoord2f(0, 1);
 180         glVertex2f(0, win_height);
 181         glEnd();
 182
 183         if(drag) {
 184                 glUseProgram(0);
 185
 186                 glEnable(GL_LOGIC_OP);
 187                 glLogicOp(GL_XOR);
 188
 189                 glBegin(GL_LINE_LOOP);
 190                 glColor3f(1, 1, 1);
 191                 glVertex2f(drag_x, drag_y);
 192                 glVertex2f(mouse_x, drag_y);
 193                 glVertex2f(mouse_x, mouse_y);
 194                 glVertex2f(drag_x, mouse_y);
 195                 glEnd();
 196
 197                 glDisable(GL_LOGIC_OP);
 198         }
 199
 200         glutSwapBuffers();
 201 }
 202
 203 static void reshape(int x, int y)
 204 {
 205         win_width = x;
 206         win_height = y;
 207         win_aspect = (float)x / (float)y;
 208
 209         glViewport(0, 0, x, y);
 210
 211         glMatrixMode(GL_PROJECTION);
 212         glLoadIdentity();
 213         glOrtho(0, x, y, 0, -1, 1);
 214
 215         reshape_pending = 1;
 216         post_redisplay();
 217 }
 218
 219 static void keyb(unsigned char key, int x, int y)
 220 {
 221         if(key == 27) {
 222                 glutExit();
 223                 quit = 1;
 224         }
 225         post_redisplay();
 226 }
 227
 228 static void mouse(int bn, int st, int x, int y)
 229 {
 230         int rect[4];
 231
 232         mouse_x = x;
 233         mouse_y = y;
 234
 235         if(bn == 0) {
 236                 if(st == GLUT_DOWN) {
 237                         drag = 1;
 238                         drag_x = x;
 239                         drag_y = y;
 240                 } else {
 241                         if(drag) {
 242                                 drag = 0;
 243
 244                                 rect[0] = x < drag_x ? x : drag_x;
 245                                 rect[1] = y < drag_y ? y : drag_y;
 246                                 rect[2] = abs(x - drag_x);
 247                                 rect[3] = abs(y - drag_y);
 248
 249                                 erb_queue_block(erb, 0, rect[0], rect[1], rect[2], rect[3]);
 250                                 printf("rect: %d,%d %dx%d\n", rect[0], rect[1], rect[2], rect[3]);
 251                         }
 252                 }
 253
 254                 post_redisplay();
 255         }
 256         if(bn == 2 && st == GLUT_DOWN) {
 257                 drag = 0;
 258                 post_redisplay();
 259         }
 260 }
 261
 262 static void motion(int x, int y)
 263 {
 264         mouse_x = x;
 265         mouse_y = y;
 266
 267         post_redisplay();
 268 }