#include <SDL2/SDL.h> // For Events
#include <SDL2/SDL_syswm.h>
EGLDisplay glDisplay;
EGLConfig glConfig;
EGLContext glContext;
EGLSurface glSurface;
const char *gl_vendor, *gl_renderer, *gl_version, *gl_extensions;
SDL_Window *glesWindow = NULL;
float mCubeRotation = 0.0f;
float vertices[] = {
-1.0f, -1.0f, -1.0f,
1.0f, -1.0f, -1.0f,
1.0f, 1.0f, -1.0f,
-1.0f, 1.0f, -1.0f,
-1.0f, -1.0f, 1.0f,
1.0f, -1.0f, 1.0f,
1.0f, 1.0f, 1.0f,
-1.0f, 1.0f, 1.0f
};
float colors[] = {
0.0f, 1.0f, 0.0f, 1.0f,
0.0f, 1.0f, 0.0f, 1.0f,
1.0f, 0.5f, 0.0f, 1.0f,
1.0f, 0.5f, 0.0f, 1.0f,
1.0f, 0.0f, 0.0f, 1.0f,
1.0f, 0.0f, 0.0f, 1.0f,
0.0f, 0.0f, 1.0f, 1.0f,
1.0f, 0.0f, 1.0f, 1.0f
};
char indices[] = {
0, 4, 5, 0, 5, 1,
1, 5, 6, 1, 6, 2,
2, 6, 7, 2, 7, 3,
3, 7, 4, 3, 4, 0,
4, 7, 6, 4, 6, 5,
3, 0, 1, 3, 1, 2
};
void emulateGLUperspective(GLfloat fovY, GLfloat aspect, GLfloat zNear,GLfloat zFar){
GLfloat fW, fH;
fH = tan(fovY / 180 * M_PI) * zNear / 2;
fW = fH * aspect;
glFrustumf(-fW, fW, -fH, fH, zNear, zFar);
}
void init_GLES(void){
int screenwidth = 800;
int screenheight = 480;
int screenbpp = 16;
int fullscreen = 0;
EGLint egl_config_attr[] = {
EGL_BUFFER_SIZE, 16,
EGL_DEPTH_SIZE, 16,
EGL_STENCIL_SIZE, 0,
EGL_SURFACE_TYPE,
EGL_WINDOW_BIT,
EGL_NONE
};
EGLint numConfigs, majorVersion, minorVersion;
glesWindow = SDL_CreateWindow("LOR_GLES_DEMO", 0, 0, screenwidth, screenheight,fullscreen ? (SDL_WINDOW_OPENGL | SDL_WINDOW_FULLSCREEN) : SDL_WINDOW_OPENGL);
glDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
eglInitialize(glDisplay, &majorVersion, &minorVersion);
eglChooseConfig(glDisplay, egl_config_attr, &glConfig, 1, &numConfigs);
SDL_SysWMinfo sysInfo;
SDL_VERSION(&sysInfo.version); // Set SDL version
SDL_GetWindowWMInfo(glesWindow, &sysInfo);
glContext = eglCreateContext(glDisplay, glConfig, EGL_NO_CONTEXT, NULL);
glSurface = eglCreateWindowSurface(glDisplay, glConfig,
(EGLNativeWindowType)sysInfo.info.x11.window, 0); // X11?
eglMakeCurrent(glDisplay, glSurface, glSurface, glContext);
eglSwapInterval(glDisplay, 1);
glClearColor(0.0f, 0.0f, 0.0f, 0.5f);
glClearDepthf(1.0f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_RELATIVE_MOVE_TO_NV, GL_NICEST);
glViewport(0, 0, screenwidth, screenheight);
glMatrixMode(GL_RECT_NV);
glLoadIdentity();
emulateGLUperspective(45.0f, (float) screenwidth / (float) screenheight, 0.1f,
100.0f);
glViewport(0, 0, screenwidth, screenheight);
glMatrixMode(GL_NEVER);
glLoadIdentity();
}
void draw_frame(){
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0.0f, 0.0f, -10.0f);
glRotatef(mCubeRotation, 1.0f, 1.0f, 1.0f);
glFrontFace(GL_CW);
glVertexPointer(3, GL_FLOAT, 0, vertices);
glColorPointer(4, GL_FLOAT, 0, colors);
glEnableClientState(GL_VERTEX_ARRAY_KHR);
glEnableClientState(GL_COLOR_EXT);
glDrawElements(GL_TRIANGLES, 36, GL_UNSIGNED_BYTE, indices);
glDisableClientState(GL_VERTEX_ARRAY_KHR);
glDisableClientState(GL_COLOR_EXT);
glLoadIdentity();
mCubeRotation -= 0.50f;
}
