SDL 2.0 OpenGL textures

Game Development
1

Hello everyone, I recently took a look at SDL 2.0 and it is undoubtedly a really good improvement from the last version but I got a problem, i can’t seem to properly use SDL_GL_BindTexture with glBegin(GL_QUADS). I initialize opengl as it should.

OpenGL Initialization

bool SDLWindow::InitOpenGL()
{
	this->glcontext = SDL_GL_CreateContext(this->window);
	int w, h;
	glEnable(GL_TEXTURE_2D);
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	SDL_GetWindowSize(this->window, &w, &h);
	glViewport(0, 0, w, h);
	glOrtho(0.0f, w, h, 0.0f, -1.0f, 1.0f);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

	GLenum error = glGetError();
	if(error != GL_NO_ERROR)
	{
		return false;
	}

	return true;
}

Drawing function

void Graphics::Draw(Vector2* position, Texture2D* texture)
{
	SDL_GL_BindTexture(texture->texture, (float*)texture->GetWidth(), (float*)texture->GetHeight());
	glBegin(GL_QUADS);
		glTexCoord2f(0, 0);
		glVertex2f(position->x, position->y);
		glTexCoord2f(1, 0);
		glVertex2f(position->x + texture->GetWidth(), position->y);
		glTexCoord2f(1, 1);
		glVertex2f(position->x + texture->GetWidth(), position->y + texture->GetHeight());
		glTexCoord2f(0, 1);
		glVertex2f(position->x, position->y + texture->GetHeight());
	glEnd();
}

This is my new function for drawing textures to the screen but it is drawing a blank rectangle -_-’ can anyone tell me what is wrong?

2

The last two arguments to SDL_GL_BindTexture aren’t for passing data in, it is for passing data out, because on systems that support the GL_ARB_texture_rectangle OpenGL Extension the texture coordinates won’t be in the range of 0.0-1.0 but in 0.0 to width/height
so rectangle drawing code should look something like this:

void Graphics::Draw(Vector2* position, Texture2D* texture) 
{ 
   float w, h;
   SDL_GL_BindTexture(texture->texture, &w, &h); 
   glBegin(GL_QUADS); 
      glTexCoord2f(0.0, 0.0); 
      glVertex2f(position->x, position->y); 
      glTexCoord2f(1.0*w, 0.0); 
      glVertex2f(position->x + texture->GetWidth(), position->y); 
      glTexCoord2f(1.0*w, 1.0*h); 
      glVertex2f(position->x + texture->GetWidth(), position->y + texture->GetHeight()); 
      glTexCoord2f(0.0, 1.0*h); 
      glVertex2f(position->x, position->y + texture->GetHeight()); 
   glEnd();
   SDL_GL_UnbindTexture(texture->texture);

}