demotool/fxaa.cc

#include "externals.hh"
#include "fxaa.hh"
#include "profiling.hh"
#include "globals.hh"

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

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


T_FXAAPass::T_FXAAPass(
		__rw__ T_Texture& input )
	: txInput_( input ) ,
		parameters_{ .5 , .166 , .0833 }
{
	program_ = Globals::Shaders( ).pipeline({
			"fullscreen.v.glsl" , "fxaa.f.glsl" });
}

void T_FXAAPass::render( )
{
	PSTART( );
	T_Rendertarget::MainOutput( );
	glClearColor( 1 , 0 , 1 , 1 );
	glClear( GL_COLOR_BUFFER_BIT );
	if ( program_.valid( ) ) {
		enum {
			U_INPUT ,
			U_RESOLUTION ,
			U_PARAMETERS ,
		};
		auto& tm( Globals::Textures( ) );
		tm.bind( 0 , txInput_ , *tm.sampler( "linear-border" ) );

		const auto id( program_.program( E_ShaderType::FRAGMENT ) );
		program_.enable( );
		glProgramUniform1i( id , U_INPUT , 0 );
		glProgramUniform2f( id , U_RESOLUTION ,
				txInput_.width( ) , txInput_.height( ) );
		glProgramUniform3fv( id , U_PARAMETERS , 1 , parameters_ );

		glDrawArrays( GL_TRIANGLE_STRIP , 0 , 4 );
	}
	PEND( );
}

void T_FXAAPass::makeUI( )
{
	using namespace ImGui;
	if ( !CollapsingHeader( "FXAA" ) ) {
		return;
	}

	DragFloat( "Sub-pixel q." , &parameters_[ 0 ] , .001f , 0 , 1 );
	DragFloat( "Edge threshold" , &parameters_[ 1 ] , .0001f , .063 , .333 );
	DragFloat( "Edge threshold min" , &parameters_[ 2 ] , .0001f , .0312 , .0833 );
}