GLESv2 sample working

[sdlhildon] / sdlgles / test / gles2.c

diff --git a/sdlgles/test/gles2.c b/sdlgles/test/gles2.c
new file mode 100644 (file)
index 0000000..3e35e73
--- /dev/null
+++ b/sdlgles/test/gles2.c
@@ -0,0 +1,151 @@
+/* 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;
+}