clop
Member
- Joined
 - Aug 17, 2010
 
- Messages
 - 176
 
Hi fellow developers,
Here's a question for you. I'm just starting to experiment with openGL and I've understood that GLES1 was a subset of GL1, and that a working GLES1 code would work with a "standard" openGL.
But my experiments proved me wrong. So, am I right? Is my experiment right? Please, help me
My experiment: Drawing a single coloured triangle.
Relevant code:
	
	
	
		
For openGL, I use SDL with flag SDL_OPENGL flag, for openGLES I use EGL.
Result are attached, first one is openGL and second and correct one (I guess) is openGLES rendering.
		
		
	
	

				
			Here's a question for you. I'm just starting to experiment with openGL and I've understood that GLES1 was a subset of GL1, and that a working GLES1 code would work with a "standard" openGL.
But my experiments proved me wrong. So, am I right? Is my experiment right? Please, help me
My experiment: Drawing a single coloured triangle.
Relevant code:
		Code:
	
	#if !defined(HAVE_GLES)
	#define GLfloat	 GLdouble
	#define GL_CLAMP_TO_EDGE	 GL_CLAMP
	#define glClearDepthf glClearDepth
	#define glOrthof	  glOrtho
#endif
GLfloat triangle[] = {
	0.125f, 0.125f, 0.0f,
	0.75f, 0.125f, 0.0f,
	0.125f, 0.75f, 0.0f
};
GLfloat colors[] = {
	0.0f, 0.0f, 1.0f, 1.0f,
	0.0f, 1.0f, 0.0f, 1.0f,
	1.0f, 0.0f, 0.0f, 1.0f
};
void initGL()
{
	glClearColor (0.0f, 0.0f, 0.0f, 0.0f);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrthof(0.0f, 1.0f, 0.0f, 1.0f, -1.0f, 1.0f);
	glShadeModel(GL_SMOOTH);
}
void drawTriangle(GLfloat *vertices, GLfloat *color)
{
	glEnableClientState(GL_VERTEX_ARRAY);
	glVertexPointer(3, GL_FLOAT, 0, vertices);
	glEnableClientState(GL_COLOR_ARRAY);
	glColorPointer(4, GL_FLOAT, 0, color);
	glDrawArrays(GL_TRIANGLES, 0, 3);
	glDisableClientState(GL_COLOR_ARRAY);
	glDisableClientState(GL_VERTEX_ARRAY);
}
	For openGL, I use SDL with flag SDL_OPENGL flag, for openGLES I use EGL.
Result are attached, first one is openGL and second and correct one (I guess) is openGLES rendering.


			
				Last edited by a moderator: 
			
		
	
								
								
									
	
								
							
							
	