source: data/branches/Shader_HS18/programs/Example/GLSLES/Instancing.frag @ 12091

//---------------------------------------------------------------------------
//These materials/shaders are part of the NEW InstanceManager implementation
//Written by Matias N. Goldberg ("dark_sylinc")
//---------------------------------------------------------------------------

#version 300 es

precision mediump int;
precision mediump float;

uniform sampler2D diffuseMap;

uniform vec4    lightPosition;
uniform vec3    cameraPosition;
uniform vec3    lightAmbient;
uniform vec3    lightDiffuse;
uniform vec3    lightSpecular;
uniform vec4    lightAttenuation;
uniform float   lightGloss;

#if DEPTH_SHADOWRECEIVER
uniform float invShadowMapSize;
uniform lowp sampler2DShadow shadowMap;

//declare external function

// Simple PCF 
// Number of samples in one dimension (square for total samples)
#define NUM_SHADOW_SAMPLES_1D 2.0
#define SHADOW_FILTER_SCALE 1.0

#define SHADOW_SAMPLES NUM_SHADOW_SAMPLES_1D*NUM_SHADOW_SAMPLES_1D

vec4 offsetSample(vec4 uv, vec2 offset, float invMapSize)
{
        return vec4(uv.xy + offset * invMapSize * uv.w, uv.z, uv.w);
}

float calcDepthShadow(lowp sampler2DShadow shadowMap, vec4 uv, float invShadowMapSize)
{
        // 4-sample PCF
        
        float shadow = 0.0;
        float offset = (NUM_SHADOW_SAMPLES_1D/2.0 - 0.5) * SHADOW_FILTER_SCALE;
        for (float y = -offset; y <= offset; y += SHADOW_FILTER_SCALE)
                for (float x = -offset; x <= offset; x += SHADOW_FILTER_SCALE)
                {
                        float depth = textureProj(shadowMap, offsetSample(uv, vec2(x, y), invShadowMapSize));
                        if (depth >= 1.0 || depth >= uv.z)
                                shadow += 1.0;
                }

        shadow /= SHADOW_SAMPLES;

        return shadow;
}
#endif

in vec2 _uv0;
in vec3 oNormal;
in vec3 oVPos;
#if DEPTH_SHADOWRECEIVER
        in vec4 oLightSpacePos;
#endif
out vec4 fragColour;

//---------------------------------------------
//Main Pixel Shader
//---------------------------------------------
void main(void)
{
        vec4 color = texture( diffuseMap, _uv0 );

        float fShadow = 1.0;
#if DEPTH_SHADOWRECEIVER
        fShadow = calcDepthShadow( shadowMap, oLightSpacePos, invShadowMapSize );
#endif

        vec4 baseColour = texture( diffuseMap, _uv0 );

        //Blinn-Phong lighting
        vec3 normal     = normalize( oNormal );
        vec3 lightDir           = lightPosition.xyz - oVPos * lightPosition.w;
        vec3 eyeDir                     = normalize( cameraPosition - oVPos );

        float fLength   = length( lightDir );
        lightDir                        = normalize( lightDir );

        float NdotL     = max( 0.0, dot( normal, lightDir ) );
        vec3 halfVector         = normalize(lightDir + eyeDir);
        float HdotN     = max( 0.0, dot( halfVector, normal ) );
        
        vec3 ambient  = lightAmbient * baseColour.xyz;
        vec3 diffuse  = lightDiffuse * NdotL * baseColour.xyz;
        vec3 specular = lightSpecular * pow( HdotN, lightGloss );
        
        vec3 directLighting = (diffuse + specular) * fShadow;
        
        fragColour = vec4( directLighting + ambient, baseColour.a );
        //fragColour = baseColour;
}