+/* gles1 - a simple SDL_gles OpenGL|ES 1.1 sample
+ *
+ * This file is in the public domain, furnished "as is", without technical
+ * support, and with no warranty, express or implied, as to its usefulness for
+ * any purpose.
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <assert.h>
+
+#include <SDL.h>
+#include <SDL_gles.h>
+
+#include <GLES2/gl2.h>
+
+static SDL_Surface *screen;
+static SDL_GLES_Context *context;
+
+static GLuint program;
+static bool fullscreen = false;
+
+static GLuint compile_shader(GLenum type, const char *src)
+{
+ GLuint shader = glCreateShader(type);
+ GLint compiled;
+
+ assert(shader != 0),
+ glShaderSource(shader, 1, &src, NULL);
+ glCompileShader(shader);
+ glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
+ assert(compiled);
+
+ return shader;
+}
+
+static void init()
+{
+ const char vertex_shader_src[] =
+ "attribute vec4 pos;\n"
+ "void main()\n"
+ "{\n"
+ " gl_Position = pos;\n"
+ "}\n";
+
+ const char fragment_shader_src[] =
+ "precision mediump float;\n"
+ "void main()\n"
+ "{\n"
+ " gl_FragColor = vec4 ( 1.0, 0.0, 0.0, 1.0 );\n"
+ "}\n";
+
+ GLuint vertex_shader = compile_shader(GL_VERTEX_SHADER, vertex_shader_src);
+ GLuint fragment_shader = compile_shader(GL_FRAGMENT_SHADER, fragment_shader_src);
+
+ program = glCreateProgram();
+ assert(program);
+
+ glAttachShader(program, vertex_shader);
+ glAttachShader(program, fragment_shader);
+
+ glBindAttribLocation(program, 0, "pos");
+
+ GLint linked;
+ glLinkProgram(program);
+ glGetProgramiv(program, GL_LINK_STATUS, &linked);
+ assert(linked);
+
+ glClearColor(0.0f, 0.0f, 0.2f, 0.0f);
+}
+
+static void render()
+{
+ GLfloat tri_v[] = {0.0f, 0.5f, 0.0f,
+ -0.5f, -0.5f, 0.0f,
+ 0.5f, -0.5f, 0.0f};
+
+ glViewport(0, 0, screen->w, screen->h);
+ glClear(GL_COLOR_BUFFER_BIT);
+ glUseProgram(program);
+
+ glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, tri_v);
+ glEnableVertexAttribArray(0);
+
+ glDrawArrays(GL_TRIANGLES, 0, 3);
+
+ SDL_GLES_SwapBuffers();
+}
+
+static void toggle_fullscreen()
+{
+ int res;
+
+ fullscreen = !fullscreen;
+
+ screen = SDL_SetVideoMode(0, 0, 16, SDL_SWSURFACE |
+ (fullscreen ? SDL_FULLSCREEN : 0));
+ assert(screen);
+
+ res = SDL_GLES_SetVideoMode();
+ if (res != 0) puts(SDL_GetError());
+ assert(res == 0);
+
+ render();
+}
+
+int main()
+{
+ int res;
+ res = SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER);
+ assert(res == 0);
+
+ res = SDL_GLES_Init(SDL_GLES_VERSION_2_0);
+ assert(res == 0);
+
+ screen = SDL_SetVideoMode(0, 0, 16, SDL_SWSURFACE);
+ assert(screen);
+
+ SDL_WM_SetCaption("SDLgles v2 test");
+ SDL_ShowCursor(SDL_DISABLE);
+
+ context = SDL_GLES_CreateContext();
+ if (!context) puts(SDL_GetError());
+ assert(context);
+
+ res = SDL_GLES_MakeCurrent(context);
+ assert(res == 0);
+
+ init();
+ render();
+
+ SDL_Event event;
+ while (SDL_WaitEvent(&event)) {
+ switch (event.type) {
+ case SDL_QUIT:
+ goto quit;
+ case SDL_MOUSEBUTTONDOWN:
+ toggle_fullscreen();
+ break;
+ }
+ }
+
+quit:
+ SDL_GLES_DeleteContext(context);
+
+ SDL_GLES_Quit();
+ SDL_Quit();
+
+ return 0;
+}