// Copyright (C) 2012-2015 ChaosForge Ltd
// http://chaosforge.org/
//
// This file is part of Nova libraries. 
// For conditions of distribution and use, see copying.txt file in root folder.

#include "nv/gl/gl_enum.hh"

#include "nv/lib/gl.hh"

using namespace nv;

unsigned int nv::texture_type_to_enum( texture_type type )
{
	switch( type )
	{
	case TEXTURE_1D      : return GL_TEXTURE_1D;
	case TEXTURE_2D      : return GL_TEXTURE_2D;
	case TEXTURE_RECT    : return GL_TEXTURE_RECTANGLE;
	case TEXTURE_3D      : return GL_TEXTURE_3D;
	case TEXTURE_CUBE    : return GL_TEXTURE_CUBE_MAP;
 	case TEXTURE_1D_ARRAY: return GL_TEXTURE_1D_ARRAY;
 	case TEXTURE_2D_ARRAY: return GL_TEXTURE_2D_ARRAY;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::clear_state_buffers_to_mask( clear_state::buffers_type type )
{
	unsigned int mask = 0;
	if ( (type & clear_state::COLOR_BUFFER) != 0 )   mask |= GL_COLOR_BUFFER_BIT;
	if ( (type & clear_state::DEPTH_BUFFER) != 0 )   mask |= GL_DEPTH_BUFFER_BIT;
	if ( (type & clear_state::STENCIL_BUFFER) != 0 ) mask |= GL_STENCIL_BUFFER_BIT;
	return mask;
}

unsigned int nv::depth_state_function_to_enum( depth_test::function_type type )
{
	switch( type )
	{
	case depth_test::NEVER            : return GL_NEVER;
	case depth_test::LESS             : return GL_LESS;
	case depth_test::EQUAL            : return GL_EQUAL;
	case depth_test::LESS_OR_EQUAL    : return GL_LEQUAL;
	case depth_test::GREATER          : return GL_GREATER;
	case depth_test::NOT_EQUAL        : return GL_NOTEQUAL;
	case depth_test::GREATER_OR_EQUAL : return GL_GEQUAL;
	case depth_test::ALWAYS           : return GL_ALWAYS;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::polygon_mode_fill_to_enum( polygon_mode::fill_type type )
{
	switch( type )
	{
	case polygon_mode::FILL           : return GL_FILL;
	case polygon_mode::LINE           : return GL_LINE;
	case polygon_mode::POINT          : return GL_POINT;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}



unsigned int nv::blending_factor_to_enum( blending::factor type )
{
	switch( type )
	{
	case blending::ZERO                    : return GL_ZERO;
	case blending::ONE                     : return GL_ONE;
	case blending::SRC_COLOR               : return GL_SRC_COLOR;
	case blending::ONE_MINUS_SRC_COLOR     : return GL_ONE_MINUS_SRC_COLOR;
	case blending::DST_COLOR               : return GL_DST_COLOR;
	case blending::ONE_MINUS_DST_COLOR     : return GL_ONE_MINUS_DST_COLOR;
	case blending::SRC_ALPHA               : return GL_SRC_ALPHA;
	case blending::ONE_MINUS_SRC_ALPHA     : return GL_ONE_MINUS_SRC_ALPHA;
	case blending::DST_ALPHA               : return GL_DST_ALPHA;
	case blending::ONE_MINUS_DST_ALPHA     : return GL_ONE_MINUS_DST_ALPHA;
	case blending::CONSTANT_COLOR          : return GL_CONSTANT_COLOR;
	case blending::ONE_MINUS_CONSTANT_COLOR: return GL_ONE_MINUS_CONSTANT_COLOR;
	case blending::CONSTANT_ALPHA          : return GL_CONSTANT_ALPHA;
	case blending::ONE_MINUS_CONSTANT_ALPHA: return GL_ONE_MINUS_CONSTANT_ALPHA;
	case blending::SRC_ALPHA_SATURATE      : return GL_SRC_ALPHA_SATURATE;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::blending_equation_to_enum( blending::equation type )
{
	switch( type )
	{
	case blending::ADD              : return GL_FUNC_ADD;
	case blending::SUBTRACT         : return GL_FUNC_SUBTRACT;
	case blending::REVERSE_SUBTRACT : return GL_FUNC_REVERSE_SUBTRACT;
	case blending::MINIMUM          : return GL_MIN;
	case blending::MAXIMUM          : return GL_MAX;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::culling_face_type_to_enum( culling::face_type type )
{
	switch( type )
	{
	case culling::FRONT          : return GL_FRONT;
	case culling::BACK           : return GL_BACK;
	case culling::FRONT_AND_BACK : return GL_FRONT_AND_BACK;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::culling_order_type_to_enum( culling::order_type type )
{
	switch( type )
	{
	case culling::CW   : return GL_CW;
	case culling::CCW  : return GL_CCW;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::stencil_function_to_enum( stencil_test_face::function_type type )
{
	switch( type )
	{
	case stencil_test_face::NEVER            : return GL_NEVER;
	case stencil_test_face::LESS             : return GL_LESS;
	case stencil_test_face::EQUAL            : return GL_EQUAL;
	case stencil_test_face::LESS_OR_EQUAL    : return GL_LEQUAL;
	case stencil_test_face::GREATER          : return GL_GREATER;
	case stencil_test_face::NOT_EQUAL        : return GL_NOTEQUAL;
	case stencil_test_face::GREATER_OR_EQUAL : return GL_GEQUAL;
	case stencil_test_face::ALWAYS           : return GL_ALWAYS;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::stencil_operation_to_enum( stencil_test_face::operation type )
{
	switch( type )
	{
	case stencil_test_face::ZERO             : return GL_ZERO;
	case stencil_test_face::INVERT           : return GL_INVERT;
	case stencil_test_face::KEEP             : return GL_KEEP;
	case stencil_test_face::REPLACE          : return GL_REPLACE;
	case stencil_test_face::INCREMENT        : return GL_INCR;
	case stencil_test_face::DECREMENT        : return GL_DECR;
	case stencil_test_face::INCREMENT_WRAP   : return GL_INCR_WRAP;
	case stencil_test_face::DECREMENT_WRAP   : return GL_DECR_WRAP;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::buffer_hint_to_enum( buffer_hint hint )
{
	switch( hint )
	{
	case STATIC_DRAW   : return GL_STATIC_DRAW;
	case STREAM_DRAW   : return GL_STREAM_DRAW;
	case DYNAMIC_DRAW  : return GL_DYNAMIC_DRAW;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::buffer_type_to_enum( buffer_type type )
{
	switch( type )
	{
	case VERTEX_BUFFER : return GL_ARRAY_BUFFER;
	case INDEX_BUFFER  : return GL_ELEMENT_ARRAY_BUFFER;
		NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::image_format_to_enum( pixel_format format )
{
	switch( format )
	{
	case RGB     : return GL_RGB;
	case RGBA    : return GL_RGBA;
	case RGB32F  : return GL_RGB;
	case RGBA32F : return GL_RGBA;
	case RGB16F  : return GL_RGB;
	case RGBA16F : return GL_RGBA;
	case BGR     : return GL_BGR;
	case BGRA    : return GL_BGRA;
	case RED     : return GL_RED;
	case R16F    : return GL_RED;
	case R32F    : return GL_RED;
	case DEPTH16 : return GL_DEPTH_COMPONENT;
	case DEPTH24 : return GL_DEPTH_COMPONENT;
	case DEPTH32 : return GL_DEPTH_COMPONENT;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::image_format_to_internal_enum( pixel_format format )
{
	switch( format )
	{
	case RGB     : return GL_RGB8;
	case RGBA    : return GL_RGBA8;
	case RGB32F  : return GL_RGB32F;
	case RGBA32F : return GL_RGBA32F;
	case RGB16F  : return GL_RGBA16F;
	case RGBA16F : return GL_RGBA16F;
	case BGR     : return GL_RGB8;
	case BGRA    : return GL_RGBA8;
	case RED     : return GL_R8;
	case R16F    : return GL_R16F;
	case R32F    : return GL_R32F;
	case DEPTH16 : return GL_DEPTH_COMPONENT16;
	case DEPTH24 : return GL_DEPTH_COMPONENT24;
	case DEPTH32:  return GL_DEPTH_COMPONENT32;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}


unsigned int nv::sampler_filter_to_enum( sampler::filter filter )
{
	switch( filter )
	{
	case sampler::LINEAR                 : return GL_LINEAR;
	case sampler::NEAREST                : return GL_NEAREST;
	case sampler::NEAREST_MIPMAP_NEAREST : return GL_NEAREST_MIPMAP_NEAREST;
	case sampler::LINEAR_MIPMAP_NEAREST  : return GL_LINEAR_MIPMAP_NEAREST;
	case sampler::NEAREST_MIPMAP_LINEAR  : return GL_NEAREST_MIPMAP_LINEAR;
	case sampler::LINEAR_MIPMAP_LINEAR   : return GL_LINEAR_MIPMAP_LINEAR;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::sampler_wrap_to_enum( sampler::wrap wrap )
{
	switch( wrap )
	{
	case sampler::CLAMP_TO_EDGE   : return GL_CLAMP_TO_EDGE;
	case sampler::CLAMP_TO_BORDER : return GL_CLAMP_TO_BORDER;
	case sampler::MIRRORED_REPEAT : return GL_MIRRORED_REPEAT;
	case sampler::REPEAT          : return GL_REPEAT;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::primitive_to_enum( primitive p )
{
	switch( p )
	{
	case POINTS         : return GL_POINTS;
	case LINES          : return GL_LINES;
	case LINE_LOOP      : return GL_LINE_LOOP;
	case LINE_STRIP     : return GL_LINE_STRIP;
	case TRIANGLES      : return GL_TRIANGLES;
	case TRIANGLE_STRIP : return GL_TRIANGLE_STRIP;
	case TRIANGLE_FAN   : return GL_TRIANGLE_FAN;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}

unsigned int nv::framebuffer_slot_to_enum( framebuffer_slot slot )
{
	switch( slot )
	{
	case READ_FRAMEBUFFER : return GL_READ_FRAMEBUFFER;
	case DRAW_FRAMEBUFFER : return GL_DRAW_FRAMEBUFFER;
	case FRAMEBUFFER      : return GL_FRAMEBUFFER;
	NV_RETURN_COVERED_DEFAULT( 0 );
	}
}


unsigned int nv::output_slot_to_enum( output_slot slot )
{
	switch( slot )
	{
	case OUTPUT_0 : return GL_COLOR_ATTACHMENT0;
	case OUTPUT_1 : return GL_COLOR_ATTACHMENT1;
	case OUTPUT_2 : return GL_COLOR_ATTACHMENT2;
	case OUTPUT_3 : return GL_COLOR_ATTACHMENT3;
	case OUTPUT_4 : return GL_COLOR_ATTACHMENT4;
	case OUTPUT_5 : return GL_COLOR_ATTACHMENT5;
	case OUTPUT_6 : return GL_COLOR_ATTACHMENT6;
	case OUTPUT_7 : return GL_COLOR_ATTACHMENT7;
	case OUTPUT_NONE  : return 0;
	case OUTPUT_FRONT : return GL_FRONT;
	case OUTPUT_BACK  : return GL_BACK;
		NV_RETURN_COVERED_DEFAULT( 0 );
	}
}


unsigned int nv::datatype_to_gl_enum( datatype type )
{
	switch( type )
	{
	case BYTE           : return GL_BYTE;
	case UBYTE          : return GL_UNSIGNED_BYTE;
	case SHORT          : return GL_SHORT;
	case USHORT         : return GL_UNSIGNED_SHORT;
	case INT            : return GL_INT;
	case UINT	        : return GL_UNSIGNED_INT;
	case FLOAT          : return GL_FLOAT;
	case FLOAT_VECTOR_2 : return GL_FLOAT_VEC2;
	case FLOAT_VECTOR_3 : return GL_FLOAT_VEC3;
	case FLOAT_VECTOR_4 : return GL_FLOAT_VEC4;
	case FLOAT_MATRIX_2 : return GL_FLOAT_MAT2;
	case FLOAT_MATRIX_3 : return GL_FLOAT_MAT3;
	case FLOAT_MATRIX_4 : return GL_FLOAT_MAT4;
	case INT_VECTOR_2   : return GL_INT_VEC2;
	case INT_VECTOR_3   : return GL_INT_VEC3;
	case INT_VECTOR_4   : return GL_INT_VEC4;
	// remove, error or ?
	case BYTE_VECTOR_2  : return GL_INT_VEC2;
	case BYTE_VECTOR_3  : return GL_INT_VEC3;
	case BYTE_VECTOR_4  : return GL_INT_VEC4;
		// remove, error or ?
	case UBYTE_VECTOR_2: return GL_INT_VEC2;
	case UBYTE_VECTOR_3: return GL_INT_VEC3;
	case UBYTE_VECTOR_4: return GL_INT_VEC4;
	default: return 0; // TODO: throw!
	}
}

nv::datatype nv::gl_enum_to_datatype( unsigned int gl_enum )
{
	switch( gl_enum )
	{
	case GL_BYTE           : return BYTE;
	case GL_UNSIGNED_BYTE  : return UBYTE;
	case GL_SHORT          : return SHORT;
	case GL_UNSIGNED_SHORT : return USHORT;
	case GL_INT            : return INT;
	case GL_UNSIGNED_INT   : return UINT;
	case GL_FLOAT          : return FLOAT;
	case GL_FLOAT_VEC2     : return FLOAT_VECTOR_2;
	case GL_FLOAT_VEC3     : return FLOAT_VECTOR_3;
	case GL_FLOAT_VEC4     : return FLOAT_VECTOR_4;
	case GL_FLOAT_MAT2     : return FLOAT_MATRIX_2;
	case GL_FLOAT_MAT3     : return FLOAT_MATRIX_3;
	case GL_FLOAT_MAT4     : return FLOAT_MATRIX_4;
	case GL_INT_VEC2       : return INT_VECTOR_2;
	case GL_INT_VEC3       : return INT_VECTOR_3;
	case GL_INT_VEC4       : return INT_VECTOR_4;
// TODO: separate types?
	case GL_SAMPLER_1D             : return INT;
	case GL_SAMPLER_2D             : return INT;
	case GL_SAMPLER_3D             : return INT;
	case GL_SAMPLER_2D_RECT        : return INT;
	case GL_SAMPLER_2D_RECT_SHADOW : return INT;
	case GL_SAMPLER_CUBE           : return INT;
	case GL_SAMPLER_1D_SHADOW      : return INT;	
	case GL_SAMPLER_2D_SHADOW      : return INT;
	case GL_SAMPLER_1D_ARRAY       : return INT;
	case GL_SAMPLER_2D_ARRAY       : return INT;
	case GL_SAMPLER_1D_ARRAY_SHADOW: return INT;
	case GL_SAMPLER_2D_ARRAY_SHADOW: return INT;
		// TODO: implement?
//	case GL_BOOL	
//	case GL_BOOL_VEC2
//	case GL_BOOL_VEC3
//	case GL_BOOL_VEC4
//	case GL_FLOAT_MAT2x3	
//	case GL_FLOAT_MAT2x4	
//	case GL_FLOAT_MAT3x2	
//	case GL_FLOAT_MAT3x4	
//	case GL_FLOAT_MAT4x2	
//	case GL_FLOAT_MAT4x3	
	default : return datatype(0); // TODO: throw!
	}
}

string_view nv::datatype_to_glsl_type( datatype type )
{
	switch( type )
	{
	case INT            : return "int";
	case FLOAT          : return "float";
	case FLOAT_VECTOR_2 : return "vec2";
	case FLOAT_VECTOR_3 : return "vec3";
	case FLOAT_VECTOR_4 : return "vec4";
	case FLOAT_MATRIX_2 : return "mat2";
	case FLOAT_MATRIX_3 : return "mat3";
	case FLOAT_MATRIX_4 : return "mat4";
	case INT_VECTOR_2   : return "ivec2";
	case INT_VECTOR_3   : return "ivec3";
	case INT_VECTOR_4   : return "ivec4";
	default : return "error";
	}
}