#include "externals.hh"
#include "bloom.hh"
#include "profiling.hh"
#include "globals.hh"
#include "odbg.hh"

namespace {
	static char const* const Name_( "BLOOOOM!" );
}

#define PSTART() Globals::Profiler( ).start( Name_ )
#define PEND() do { glFinish( ); Globals::Profiler( ).end( Name_ ); } while ( 0 )


T_BloomPass::T_BloomPass(
		__rw__ T_Texture& input )
	: input_( input ) ,
		//
		txBlur0_( input.width( ) , input.height( ) , E_TexType::RGB16F , BloomLevels ) ,
		txBlur1_( input.width( ) , input.height( ) , E_TexType::RGB16F , BloomLevels ) ,
		//
		filterParams_{ 1.6 , 1.2 , .95 } ,
		blurWeights_{ 0.324 , 0.232 , 0.0855 , 0.0205 } ,
		blurSize_{ 1.3 }
{
	txBlur0_.wrap( E_TexWrap::CLAMP_EDGE ).samplingMode( E_TexSampling::LINEAR );
	txBlur1_.wrap( E_TexWrap::CLAMP_EDGE ).samplingMode( E_TexSampling::LINEAR );
	Globals::ODbg( ).registerTexture( txBlur0_ , E_ODbgMode::HDR , "Bloom" );

	for ( auto i = 0u ; i < BloomLevels ; i ++ ) {
		rtBlur0_.add( T_RendertargetSetup( ).add( txBlur0_ , i ).create( ) );
		rtBlur1_.add( T_RendertargetSetup( ).add( txBlur1_ , i ).create( ) );
	}

	auto& sm( Globals::Shaders( ) );
	spHighpass_ = sm.pipeline({ "fullscreen.v.glsl" , "bloom-highpass.f.glsl" });
	spDownsample_ = sm.pipeline({ "fullscreen.v.glsl" , "downsample.f.glsl" });
	spBlur_ = sm.pipeline({ "fullscreen.v.glsl" , "blur-pass.f.glsl" });
}

void T_BloomPass::render( )
{
	if ( !( spHighpass_.valid( ) && spBlur_.valid( ) && spDownsample_.valid( ) ) ) {
		return;
	}

	PSTART( );
	auto& tm( Globals::Textures( ) );
	{
		rtBlur0_[ 0 ].activate( );
		const auto hpf( spHighpass_.program( E_ShaderType::FRAGMENT ) );
		enum {
			U_TEXTURE		= 0 ,
			U_LOD			= 1 ,
			U_INPUT_SIZE		= 2 ,
			U_PARAMS		= 3 ,
		};

		tm.bind( 0 , input_ );
		spHighpass_.enable( );

		glProgramUniform1i( hpf , U_TEXTURE , 0 );
		glProgramUniform1i( hpf , U_LOD , 0 );
		glProgramUniform2f( hpf , U_INPUT_SIZE ,
				input_.width( ) ,
				input_.height( ) );
		glProgramUniform3fv( hpf , U_PARAMS , 1 , filterParams_ );
		glDrawArrays( GL_TRIANGLE_STRIP , 0 , 4 );
	}

	enum {
		U_TEXTURE		= 0 ,
		U_OUTPUT_SIZE		= 1 ,
		U_SOURCE_LOD		= 2 ,
		U_DIRECTION		= 3 ,
		U_WEIGHTS		= 4 ,
	};

	const auto dsf( spDownsample_.program( E_ShaderType::FRAGMENT ) );
	const auto bpf( spBlur_.program( E_ShaderType::FRAGMENT ) );
	glProgramUniform1i( dsf , 0 , 0 );
	glProgramUniform4fv( bpf , U_WEIGHTS , 1 , blurWeights_ );
	glProgramUniform1i( bpf , U_TEXTURE , 0 );

	for ( auto i = 0u ; i < BloomLevels ; i ++ ) {
		if ( i > 0 ) {
			spDownsample_.enable( );
			rtBlur0_[ i ].activate( );

			tm.bind( 0 , txBlur0_ );

			glProgramUniform2f( dsf , 1 , txBlur0_.width( ) >> i ,
					txBlur0_.height( ) >> i );
			glProgramUniform1i( dsf , 2 , i - 1 );

			glDrawArrays( GL_TRIANGLE_STRIP , 0 , 4 );
		}

		spBlur_.enable( );
		glProgramUniform2f( bpf , U_OUTPUT_SIZE , rtBlur0_[ i ].width( ) ,
				rtBlur0_[ i ].height( ) );
		glProgramUniform1i( bpf , U_SOURCE_LOD , i );

		rtBlur1_[ i ].activate( );
		glProgramUniform2f( bpf , U_DIRECTION , blurSize_ , 0 );
		tm.bind( 0 , txBlur0_ );
		glDrawArrays( GL_TRIANGLE_STRIP , 0 , 4 );

		rtBlur0_[ i ].activate( );
		glProgramUniform2f( bpf , U_DIRECTION , 0 , blurSize_ );
		tm.bind( 0 , txBlur1_ );
		glDrawArrays( GL_TRIANGLE_STRIP , 0 , 4 );
	}

	PEND( );
}

void T_BloomPass::makeUI( )
{
	if ( !ImGui::CollapsingHeader( "Bloom" ) ) {
		return;
	}

	ImGui::DragFloat3( "Filter" , filterParams_ , .01f , 0.1 , 10 );
	ImGui::DragFloat4( "Weights" , blurWeights_ , .001f , 0. , 10 );
	ImGui::DragFloat( "Blur size" , &blurSize_ , .001f , 0. , 10 );
}