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