#ifndef GL_CONTEXT_HH

#define GL_CONTEXT_HH

#include "GLUtil.hh"

#include "gl_mat.hh"

#include <memory>

#include <optional>

namespace openmsx { class GLScaler; }

namespace gl {

struct Context

{

	/** Initialize global openGL state

	 */

	Context();

	~Context();

	// Simple texture program. It expects

	//  uniforms:

	//    unifTexColor: values from texture map are multiplied by this 4D color

	//    unifTexMvp: Model-View-Projection-matrix

	//  attributes:

	//    0: 4D vertex positions, get multiplied by Model-View-Projection-matrix

	//    1: 2D texture coordinates

	//  textures:

	//    the to be applied texture must be bound to the 1st texture unit

	ShaderProgram progTex;

	GLint unifTexColor;

	GLint unifTexMvp;

	// Simple color-fill program. It expects

	//  uniforms:

	//    unifFillMvp: Model-View-Projection-matrix

	//  attributes:

	//    0: 4D vertex positions, get multiplied by Model-View-Projection-matrix

	//    1: 4D vertex color

	ShaderProgram progFill;

	GLint unifFillMvp;

	// Model-View-Projection-matrix that maps integer vertex positions to host

	// display pixel positions. (0,0) is the top-left pixel, (width-1,height-1) is

	// the bottom-right pixel.

	mat4 pixelMvp;

	// Fallback scaler

	openmsx::GLScaler& getFallbackScaler();

	// Setup model-view-projection matrix. Should be called before drawing,

	// at least once after the window resolution has changed. (E.g. call it

	// once per frame).

	void setupMvpMatrix(gl::vec2 logicalSize);

private:

	std::unique_ptr<openmsx::GLScaler> fallbackScaler;

};

extern std::optional<Context> context;

} // namespace gl

#endif