source: data/branches/Shader_HS18/programs/Example/GLSLES/pssmReceiverVp.glsles @ 12091

#version 100

precision mediump int;
precision mediump float;

float shadowPCF(sampler2D shadowMap, vec4 shadowMapPos, vec2 offset)
{
        shadowMapPos = shadowMapPos / shadowMapPos.w;
        vec2 uv = shadowMapPos.xy;
        vec3 o = vec3(offset, -offset.x) * 0.3;

        // Note: We using 2x2 PCF. Good enough and is a lot faster.
        float c =       (shadowMapPos.z <= texture2D(shadowMap, uv.xy - o.xy).r) ? 1.0 : 0.0; // top left
        c +=            (shadowMapPos.z <= texture2D(shadowMap, uv.xy + o.xy).r) ? 1.0 : 0.0; // bottom right
        c +=            (shadowMapPos.z <= texture2D(shadowMap, uv.xy + o.zy).r) ? 1.0 : 0.0; // bottom left
        c +=            (shadowMapPos.z <= texture2D(shadowMap, uv.xy - o.zy).r) ? 1.0 : 0.0; // top right

        return c / 4.0;
}

uniform vec4 lightPosition;                             // object space
uniform vec3 eyePosition;                                       // object space
uniform mat4 worldViewProjMatrix;
uniform mat4 texWorldViewProjMatrix0;
uniform mat4 texWorldViewProjMatrix1;
uniform mat4 texWorldViewProjMatrix2;

varying vec4 oUv0;
varying vec3 oLightDir;
varying vec3 oHalfAngle;
varying vec4 oLightPosition0;
varying vec4 oLightPosition1;
varying vec4 oLightPosition2;
varying vec3 oNormal;

attribute vec4 position;
attribute vec3 normal;
attribute vec4 uv0;

void main()
{
        // Calculate output position
        gl_Position = worldViewProjMatrix * position;

        // Pass the main uvs straight through unchanged
        oUv0.xy = uv0.xy;
        oUv0.z = gl_Position.z;

        // Calculate tangent space light vector
        // Get object space light direction
        oLightDir = normalize(lightPosition.xyz - (position * lightPosition.w).xyz);

        // Calculate half-angle in tangent space
        vec3 eyeDir = normalize(eyePosition - position.xyz);
        oHalfAngle = normalize(eyeDir + oLightDir);     

        // Calculate the position of vertex in light space
        oLightPosition0 = texWorldViewProjMatrix0 * position;
        oLightPosition1 = texWorldViewProjMatrix1 * position;
        oLightPosition2 = texWorldViewProjMatrix2 * position;

        oNormal = normal;
}