gl.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3
   4 #include <EGL/egl.h>
   5 #include <GLES/gl.h>
   6 #include "gl_platform.h"
   7 #include "gl.h"
   8
   9 static EGLDisplay edpy;
  10 static EGLSurface esfc;
  11 static EGLContext ectxt;
  12
  13 static GLuint texture_name;
  14
  15 /* for external flips */
  16 void *gl_es_display;
  17 void *gl_es_surface;
  18
  19 static int tex_w, tex_h;
  20 static void *tex_mem;
  21
  22 static int gl_have_error(const char *name)
  23 {
  24         GLenum e = glGetError();
  25         if (e != GL_NO_ERROR) {
  26                 fprintf(stderr, "GL error: %s %x\n", name, e);
  27                 return 1;
  28         }
  29         return 0;
  30 }
  31
  32 static int gles_have_error(const char *name)
  33 {
  34         EGLint e = eglGetError();
  35         if (e != EGL_SUCCESS) {
  36                 fprintf(stderr, "%s %x\n", name, e);
  37                 return 1;
  38         }
  39         return 0;
  40 }
  41
  42 int gl_init(void *display, void *window, int *quirks, int w, int h)
  43 {
  44         EGLConfig ecfg = NULL;
  45         EGLint num_config;
  46         int retval = -1;
  47         int ret;
  48         EGLint attr[] =
  49         {
  50                 EGL_NONE
  51         };
  52
  53         ret = gl_platform_init(&display, &window, quirks);
  54         if (ret != 0) {
  55                 fprintf(stderr, "gl_platform_init failed with %d\n", ret);
  56                 goto out;
  57         }
  58
  59         for (tex_w = 1; tex_w < w; tex_w *= 2);
  60         for (tex_h = 1; tex_h < h; tex_h *= 2);
  61         tex_mem = realloc(tex_mem, tex_w * tex_h * 2);
  62         if (tex_mem == NULL) {
  63                 fprintf(stderr, "OOM\n");
  64                 goto out;
  65         }
  66
  67         edpy = eglGetDisplay((EGLNativeDisplayType)display);
  68         if (edpy == EGL_NO_DISPLAY) {
  69                 fprintf(stderr, "Failed to get EGL display\n");
  70                 goto out;
  71         }
  72
  73         if (!eglInitialize(edpy, NULL, NULL)) {
  74                 fprintf(stderr, "Failed to initialize EGL\n");
  75                 goto out;
  76         }
  77
  78         if (!eglChooseConfig(edpy, attr, &ecfg, 1, &num_config)) {
  79                 fprintf(stderr, "Failed to choose config (%x)\n", eglGetError());
  80                 goto out;
  81         }
  82
  83         if (ecfg == NULL || num_config == 0) {
  84                 fprintf(stderr, "No EGL configs available\n");
  85                 goto out;
  86         }
  87
  88         esfc = eglCreateWindowSurface(edpy, ecfg,
  89                 (EGLNativeWindowType)window, NULL);
  90         if (esfc == EGL_NO_SURFACE) {
  91                 fprintf(stderr, "Unable to create EGL surface (%x)\n",
  92                         eglGetError());
  93                 goto out;
  94         }
  95
  96         ectxt = eglCreateContext(edpy, ecfg, EGL_NO_CONTEXT, NULL);
  97         if (ectxt == EGL_NO_CONTEXT) {
  98                 fprintf(stderr, "Unable to create EGL context (%x)\n",
  99                         eglGetError());
 100                 goto out;
 101         }
 102
 103         eglMakeCurrent(edpy, esfc, esfc, ectxt);
 104
 105         glEnable(GL_TEXTURE_2D);
 106
 107         if (texture_name)
 108                 glDeleteTextures(1, &texture_name);
 109
 110         glGenTextures(1, &texture_name);
 111
 112         glBindTexture(GL_TEXTURE_2D, texture_name);
 113
 114         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, tex_w, tex_h, 0, GL_RGB,
 115                 GL_UNSIGNED_SHORT_5_6_5, tex_mem);
 116         if (gl_have_error("glTexImage2D"))
 117                 goto out;
 118
 119         // no mipmaps
 120         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 121         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 122
 123         //glViewport(0, 0, 512, 512);
 124         glLoadIdentity();
 125         glFrontFace(GL_CW);
 126         glEnable(GL_CULL_FACE);
 127
 128         glEnableClientState(GL_TEXTURE_COORD_ARRAY);
 129         glEnableClientState(GL_VERTEX_ARRAY);
 130
 131         if (gl_have_error("init"))
 132                 goto out;
 133
 134         gl_es_display = (void *)edpy;
 135         gl_es_surface = (void *)esfc;
 136         retval = 0;
 137 out:
 138         return retval;
 139 }
 140
 141 void gl_announce(void)
 142 {
 143         printf("GL_RENDERER: %s\n", (char *)glGetString(GL_RENDERER));
 144 }
 145
 146 static float vertices[] = {
 147         -1.0f,  1.0f,  0.0f, // 0    0  1
 148          1.0f,  1.0f,  0.0f, // 1  ^
 149         -1.0f, -1.0f,  0.0f, // 2  | 2  3
 150          1.0f, -1.0f,  0.0f, // 3  +-->
 151 };
 152
 153 static float texture[] = {
 154         0.0f, 0.0f, // we flip this:
 155         1.0f, 0.0f, // v^
 156         0.0f, 1.0f, //  |  u
 157         1.0f, 1.0f, //  +-->
 158 };
 159
 160 int gl_flip(const void *fb, int w, int h)
 161 {
 162         static int old_w, old_h;
 163
 164         if (fb != NULL) {
 165                 if (w != old_w || h != old_h) {
 166                         float f_w = (float)w / tex_w;
 167                         float f_h = (float)h / tex_h;
 168                         texture[1*2 + 0] = f_w;
 169                         texture[2*2 + 1] = f_h;
 170                         texture[3*2 + 0] = f_w;
 171                         texture[3*2 + 1] = f_h;
 172                         old_w = w;
 173                         old_h = h;
 174                 }
 175
 176                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, w, h,
 177                         GL_RGB, GL_UNSIGNED_SHORT_5_6_5, fb);
 178                 if (gl_have_error("glTexSubImage2D"))
 179                         return -1;
 180         }
 181
 182         glVertexPointer(3, GL_FLOAT, 0, vertices);
 183         glTexCoordPointer(2, GL_FLOAT, 0, texture);
 184         glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 185
 186         if (gl_have_error("glDrawArrays"))
 187                 return -1;
 188
 189         eglSwapBuffers(edpy, esfc);
 190         if (gles_have_error("eglSwapBuffers"))
 191                 return -1;
 192
 193         return 0;
 194 }
 195
 196 void gl_finish(void)
 197 {
 198         eglMakeCurrent(edpy, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
 199         eglDestroyContext(edpy, ectxt);
 200         ectxt = EGL_NO_CONTEXT;
 201         eglDestroySurface(edpy, esfc);
 202         esfc = EGL_NO_SURFACE;
 203         eglTerminate(edpy);
 204         edpy = EGL_NO_DISPLAY;
 205
 206         gl_es_display = (void *)edpy;
 207         gl_es_surface = (void *)esfc;
 208
 209         if (tex_mem) free(tex_mem);
 210         tex_mem = NULL;
 211
 212         gl_platform_finish();
 213 }