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 /* for external flips */
  14 void *gl_es_display;
  15 void *gl_es_surface;
  16
  17 static int gl_have_error(const char *name)
  18 {
  19         GLenum e = glGetError();
  20         if (e != GL_NO_ERROR) {
  21                 fprintf(stderr, "GL error: %s %x\n", name, e);
  22                 return 1;
  23         }
  24         return 0;
  25 }
  26
  27 static int gles_have_error(const char *name)
  28 {
  29         EGLint e = eglGetError();
  30         if (e != EGL_SUCCESS) {
  31                 fprintf(stderr, "%s %x\n", name, e);
  32                 return 1;
  33         }
  34         return 0;
  35 }
  36
  37 int gl_init(void *display, void *window, int *quirks)
  38 {
  39         EGLConfig ecfg = NULL;
  40         GLuint texture_name = 0;
  41         void *tmp_texture_mem = NULL;
  42         EGLint num_config;
  43         int retval = -1;
  44         int ret;
  45         EGLint attr[] =
  46         {
  47                 EGL_NONE
  48         };
  49
  50         ret = gl_platform_init(&display, &window, quirks);
  51         if (ret != 0) {
  52                 fprintf(stderr, "gl_platform_init failed with %d\n", ret);
  53                 goto out;
  54         }
  55
  56         tmp_texture_mem = calloc(1, 1024 * 512 * 2);
  57         if (tmp_texture_mem == NULL) {
  58                 fprintf(stderr, "OOM\n");
  59                 goto out;
  60         }
  61
  62         edpy = eglGetDisplay((EGLNativeDisplayType)display);
  63         if (edpy == EGL_NO_DISPLAY) {
  64                 fprintf(stderr, "Failed to get EGL display\n");
  65                 goto out;
  66         }
  67
  68         if (!eglInitialize(edpy, NULL, NULL)) {
  69                 fprintf(stderr, "Failed to initialize EGL\n");
  70                 goto out;
  71         }
  72
  73         if (!eglChooseConfig(edpy, attr, &ecfg, 1, &num_config)) {
  74                 fprintf(stderr, "Failed to choose config (%x)\n", eglGetError());
  75                 goto out;
  76         }
  77
  78         if (ecfg == NULL || num_config == 0) {
  79                 fprintf(stderr, "No EGL configs available\n");
  80                 goto out;
  81         }
  82
  83         esfc = eglCreateWindowSurface(edpy, ecfg,
  84                 (EGLNativeWindowType)window, NULL);
  85         if (esfc == EGL_NO_SURFACE) {
  86                 fprintf(stderr, "Unable to create EGL surface (%x)\n",
  87                         eglGetError());
  88                 goto out;
  89         }
  90
  91         ectxt = eglCreateContext(edpy, ecfg, EGL_NO_CONTEXT, NULL);
  92         if (ectxt == EGL_NO_CONTEXT) {
  93                 fprintf(stderr, "Unable to create EGL context (%x)\n",
  94                         eglGetError());
  95                 goto out;
  96         }
  97
  98         eglMakeCurrent(edpy, esfc, esfc, ectxt);
  99
 100         glEnable(GL_TEXTURE_2D);
 101
 102         glGenTextures(1, &texture_name);
 103
 104         glBindTexture(GL_TEXTURE_2D, texture_name);
 105
 106         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 1024, 512, 0, GL_RGB,
 107                 GL_UNSIGNED_SHORT_5_6_5, tmp_texture_mem);
 108         if (gl_have_error("glTexImage2D"))
 109                 goto out;
 110
 111         // no mipmaps
 112         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 113         glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 114
 115         //glViewport(0, 0, 512, 512);
 116         glLoadIdentity();
 117         glFrontFace(GL_CW);
 118         glEnable(GL_CULL_FACE);
 119
 120         glEnableClientState(GL_TEXTURE_COORD_ARRAY);
 121         glEnableClientState(GL_VERTEX_ARRAY);
 122
 123         if (gl_have_error("init"))
 124                 goto out;
 125
 126         gl_es_display = (void *)edpy;
 127         gl_es_surface = (void *)esfc;
 128         retval = 0;
 129 out:
 130         free(tmp_texture_mem);
 131         return retval;
 132 }
 133
 134 static float vertices[] = {
 135         -1.0f,  1.0f,  0.0f, // 0    0  1
 136          1.0f,  1.0f,  0.0f, // 1  ^
 137         -1.0f, -1.0f,  0.0f, // 2  | 2  3
 138          1.0f, -1.0f,  0.0f, // 3  +-->
 139 };
 140
 141 static float texture[] = {
 142         0.0f, 0.0f, // we flip this:
 143         1.0f, 0.0f, // v^
 144         0.0f, 1.0f, //  |  u
 145         1.0f, 1.0f, //  +-->
 146 };
 147
 148 int gl_flip(const void *fb, int w, int h)
 149 {
 150         static int old_w, old_h;
 151
 152         if (fb != NULL) {
 153                 if (w != old_w || h != old_h) {
 154                         float f_w = (float)w / 1024.0f;
 155                         float f_h = (float)h / 512.0f;
 156                         texture[1*2 + 0] = f_w;
 157                         texture[2*2 + 1] = f_h;
 158                         texture[3*2 + 0] = f_w;
 159                         texture[3*2 + 1] = f_h;
 160                         old_w = w;
 161                         old_h = h;
 162                 }
 163
 164                 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, w, h,
 165                         GL_RGB, GL_UNSIGNED_SHORT_5_6_5, fb);
 166                 if (gl_have_error("glTexSubImage2D"))
 167                         return -1;
 168         }
 169
 170         glVertexPointer(3, GL_FLOAT, 0, vertices);
 171         glTexCoordPointer(2, GL_FLOAT, 0, texture);
 172         glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 173
 174         if (gl_have_error("glDrawArrays"))
 175                 return -1;
 176
 177         eglSwapBuffers(edpy, esfc);
 178         if (gles_have_error("eglSwapBuffers"))
 179                 return -1;
 180
 181         return 0;
 182 }
 183
 184 void gl_finish(void)
 185 {
 186         eglMakeCurrent(edpy, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
 187         eglDestroyContext(edpy, ectxt);
 188         ectxt = EGL_NO_CONTEXT;
 189         eglDestroySurface(edpy, esfc);
 190         esfc = EGL_NO_SURFACE;
 191         eglTerminate(edpy);
 192         edpy = EGL_NO_DISPLAY;
 193
 194         gl_es_display = (void *)edpy;
 195         gl_es_surface = (void *)esfc;
 196
 197         gl_platform_finish();
 198 }