// Copyright (C) 2008 Christian Stehno
// Heavily based on the OpenGL driver implemented by Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in Irrlicht.h

#ifndef __C_OGLES_EXTENSION_HANDLER_H_INCLUDED__
#define __C_OGLES_EXTENSION_HANDLER_H_INCLUDED__

#include "IrrCompileConfig.h"

#ifdef _IRR_COMPILE_WITH_OGLES1_

#include "EDriverFeatures.h"
#include "irrTypes.h"
#include "os.h"

#include "COGLESCommon.h"

#include "COGLESCoreExtensionHandler.h"

namespace irr
{
namespace video
{

	class COGLES1ExtensionHandler : public COGLESCoreExtensionHandler
	{
	public:
		COGLES1ExtensionHandler();

		void initExtensions();

		bool queryFeature(video::E_VIDEO_DRIVER_FEATURE feature) const
		{
			switch (feature)
			{
			case EVDF_RENDER_TO_TARGET:
			case EVDF_HARDWARE_TL:
			case EVDF_MULTITEXTURE:
			case EVDF_BILINEAR_FILTER:
			case EVDF_MIP_MAP:
			case EVDF_TEXTURE_NSQUARE:
			case EVDF_STENCIL_BUFFER:
			case EVDF_ALPHA_TO_COVERAGE:
			case EVDF_COLOR_MASK:
			case EVDF_POLYGON_OFFSET:
			case EVDF_TEXTURE_MATRIX:
				return true;
			case EVDF_TEXTURE_NPOT:
				return FeatureAvailable[IRR_GL_APPLE_texture_2D_limited_npot] || FeatureAvailable[IRR_GL_OES_texture_npot];
			case EVDF_MIP_MAP_AUTO_UPDATE:
				return Version>100;
			case EVDF_BLEND_OPERATIONS:
				return FeatureAvailable[IRR_GL_OES_blend_subtract];
			case EVDF_BLEND_SEPARATE:
				return FeatureAvailable[IRR_GL_OES_blend_func_separate];
			case EVDF_FRAMEBUFFER_OBJECT:
				return FeatureAvailable[IRR_GL_OES_framebuffer_object];
			case EVDF_VERTEX_BUFFER_OBJECT:
				return Version>100;
			case EVDF_TEXTURE_COMPRESSED_DXT:
				return false; // NV Tegra need improvements here
			case EVDF_TEXTURE_COMPRESSED_PVRTC:
				return FeatureAvailable[IRR_GL_IMG_texture_compression_pvrtc];
			case EVDF_TEXTURE_COMPRESSED_ETC1:
				return FeatureAvailable[IRR_GL_OES_compressed_ETC1_RGB8_texture];
			case EVDF_TEXTURE_CUBEMAP:
				return FeatureAvailable[IRR_GL_OES_texture_cube_map];
			default:
				return true;
			};
		}

		inline void irrGlActiveTexture(GLenum texture)
		{
			glActiveTexture(texture);
		}

		inline void irrGlCompressedTexImage2D(GLenum target, GLint level, GLenum internalformat, GLsizei width, GLsizei height, GLint border,
			GLsizei imageSize, const void* data)
		{
			glCompressedTexImage2D(target, level, internalformat, width, height, border, imageSize, data);
		}

		inline void irrGlCompressedTexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height,
			GLenum format, GLsizei imageSize, const void* data)
		{
			glCompressedTexSubImage2D(target, level, xoffset, yoffset, width, height, format, imageSize, data);
		}

		inline void irrGlUseProgram(GLuint prog)
		{
		}

		inline void irrGlBindFramebuffer(GLenum target, GLuint framebuffer)
		{
#ifdef _IRR_OGLES1_USE_EXTPOINTER_
			if (pGlBindFramebufferOES)
				pGlBindFramebufferOES(target, framebuffer);
#elif defined(GL_OES_framebuffer_object)
			glBindFramebufferOES(target, framebuffer);
#endif
		}

		inline void irrGlDeleteFramebuffers(GLsizei n, const GLuint *framebuffers)
		{
#ifdef _IRR_OGLES1_USE_EXTPOINTER_
			if (pGlDeleteFramebuffersOES)
				pGlDeleteFramebuffersOES(n, framebuffers);
#elif defined(GL_OES_framebuffer_object)
			glDeleteFramebuffersOES(n, framebuffers);
#endif
		}

		inline void irrGlGenFramebuffers(GLsizei n, GLuint *framebuffers)
		{
#ifdef _IRR_OGLES1_USE_EXTPOINTER_
			if (pGlGenFramebuffersOES)
				pGlGenFramebuffersOES(n, framebuffers);
#elif defined(GL_OES_framebuffer_object)
			glGenFramebuffersOES(n, framebuffers);
#endif
		}

		inline GLenum irrGlCheckFramebufferStatus(GLenum target)
		{
#ifdef _IRR_OGLES1_USE_EXTPOINTER_
			if (pGlCheckFramebufferStatusOES)
				return pGlCheckFramebufferStatusOES(target);
			else
				return 0;
#elif defined(GL_OES_framebuffer_object)
			return glCheckFramebufferStatusOES(target);
#else
			return 0;
#endif
		}

		inline void irrGlFramebufferTexture2D(GLenum target, GLenum attachment, GLenum textarget, GLuint texture, GLint level)
		{
#ifdef _IRR_OGLES1_USE_EXTPOINTER_
			if (pGlFramebufferTexture2DOES)
				pGlFramebufferTexture2DOES(target, attachment, textarget, texture, level);
#elif defined(GL_OES_framebuffer_object)
			glFramebufferTexture2DOES(target, attachment, textarget, texture, level);
#endif
		}

		inline void irrGlGenerateMipmap(GLenum target)
		{
#ifdef _IRR_OGLES1_USE_EXTPOINTER_
			if (pGlGenerateMipmapOES)
				pGlGenerateMipmapOES(target);
#elif defined(GL_OES_framebuffer_object)
			glGenerateMipmapOES(target);
#endif
		}

		inline void irrGlActiveStencilFace(GLenum face)
		{
		}

		inline void irrGlDrawBuffer(GLenum mode)
		{
		}

		inline void irrGlDrawBuffers(GLsizei n, const GLenum *bufs)
		{
		}

		inline void irrGlBlendFuncSeparate(GLenum srcRGB, GLenum dstRGB, GLenum srcAlpha, GLenum dstAlpha)
		{
#ifdef _IRR_OGLES1_USE_EXTPOINTER_
			if (pGlBlendFuncSeparateOES)
				pGlBlendFuncSeparateOES(srcRGB, dstRGB, srcAlpha, dstAlpha);
#elif defined(GL_OES_blend_func_separate)
			glBlendFuncSeparateOES(srcRGB, dstRGB, srcAlpha, dstAlpha);
#endif
		}

		inline void irrGlBlendEquation(GLenum mode)
		{
#ifdef _IRR_OGLES1_USE_EXTPOINTER_
			if (pGlBlendEquationOES)
				pGlBlendEquationOES(mode);
#elif defined(GL_OES_blend_subtract)
			glBlendEquationOES(mode);
#endif
		}

		inline void irrGlEnableIndexed(GLenum target, GLuint index)
		{
		}

		inline void irrGlDisableIndexed(GLenum target, GLuint index)
		{
		}

		inline void irrGlColorMaskIndexed(GLuint buf, GLboolean r, GLboolean g, GLboolean b, GLboolean a)
		{
		}

		inline void irrGlBlendFuncIndexed(GLuint buf, GLenum src, GLenum dst)
		{
		}

		inline void irrGlBlendFuncSeparateIndexed(GLuint buf, GLenum srcRGB, GLenum dstRGB, GLenum srcAlpha, GLenum dstAlpha)
		{
		}

		inline void irrGlBlendEquationIndexed(GLuint buf, GLenum mode)
		{
		}

		inline void irrGlBlendEquationSeparateIndexed(GLuint buf, GLenum modeRGB, GLenum modeAlpha)
		{
		}

	protected:

		u8 MaxUserClipPlanes;
		u8 MaxLights;

#if defined(_IRR_OGLES1_USE_EXTPOINTER_)
		PFNGLBLENDEQUATIONOESPROC pGlBlendEquationOES;
		PFNGLBLENDFUNCSEPARATEOESPROC pGlBlendFuncSeparateOES;
		PFNGLBINDFRAMEBUFFEROESPROC pGlBindFramebufferOES;
		PFNGLDELETEFRAMEBUFFERSOESPROC pGlDeleteFramebuffersOES;
		PFNGLGENFRAMEBUFFERSOESPROC pGlGenFramebuffersOES;
		PFNGLCHECKFRAMEBUFFERSTATUSOESPROC pGlCheckFramebufferStatusOES;
		PFNGLFRAMEBUFFERTEXTURE2DOESPROC pGlFramebufferTexture2DOES;
		PFNGLGENERATEMIPMAPOESPROC pGlGenerateMipmapOES;
#endif
	};

}
}

#endif
#endif