deferred-lighting-point-combine-stages.glsl

uniform int numLights;

uniform vec3 viewDirection;
uniform vec3 specularColor;

uniform float shininess;

uniform sampler2D samplerPos;
uniform sampler2D samplerNorm;
uniform sampler2D samplerColor;
uniform sampler2D samplerUv;

uniform samplerBuffer lightPos;
uniform samplerBuffer lightColor;
uniform samplerBuffer lightFalloff;

out vec4 fragColor;

void main()
{
    vec2 screenSpaceUV		= vUV.st;
    vec2 resolution 		= uTD2DInfos[0].res.zw;

    // parse data from g-buffer
    vec3 position 		= texture( sTD2DInputs[0], screenSpaceUV ).rgb;
    vec3 normal 		= texture( sTD2DInputs[1], screenSpaceUV ).rgb;
    vec4 color 			= texture( sTD2DInputs[2], screenSpaceUV );
    vec2 uv 			= texture( sTD2DInputs[3], screenSpaceUV ).rg;

    // set up placeholder for final color
    vec3 finalColor 	= vec3(0.0);

    // loop through all lights
    for ( int light = 0; light < numLights; ++light ){

    	// parse lighitng data based on the current light index
    	vec3 currentLightPos		= texelFetchBuffer( lightPos, light ).xyz;
    	vec3 currentLightColor		= texelFetchBuffer( lightColor, light ).xyz;
    	vec3 currentLightFalloff	= texelFetchBuffer( lightFalloff, light ).xyz;

    	// calculate the distance between the current fragment and the light source
    	float lightDist 			= length( currentLightPos - position );

    	// diffuse contrabution
    	vec3 toLight 			 	= normalize( currentLightPos - position );
    	vec3 diffuse 				= max( dot( normal, toLight ), 0.0 ) * color.rgb * currentLightColor;

    	// specular contrabution
    	vec3 toViewer 				= normalize( position - viewDirection );
    	vec3 h 						= normalize( toLight - toViewer );
    	float spec 					= pow( max( dot( normal, h ), 0.0 ), shininess );
    	vec3 specular 				= currentLightColor * spec * specularColor;

    	// attenuation
    	float attenuation 			= 1.0 / ( 1.0 + currentLightFalloff.y * lightDist + currentLightFalloff.z * lightDist * lightDist );
    	diffuse 					*= attenuation;
    	specular 					*= attenuation;

    	// accumulate lighting
    	finalColor 					+= diffuse + specular;

    }

    // final color out 
    fragColor = TDOutputSwizzle( vec4( finalColor, color.a ) );
}