#include "Uniforms.glsl"
#include "Samplers.glsl"
#include "Transform.glsl"
#include "ScreenPos.glsl"
#include "Fog.glsl"

varying vec2 vScreenPos;
varying vec2 vTexCoord;
varying vec4 vWorldPos;
varying vec3 vFarRay;
varying vec4 vPosProj;

#ifdef VERTEXCOLOR
    varying vec4 vColor;
#endif

#ifdef SP
    varying float vParticleViewProjZ;
#endif

#line 17
void VS()
{
    mat4 modelMatrix = iModelMatrix;
    vec3 worldPos = GetWorldPos(modelMatrix);
    gl_Position = GetClipPos(worldPos);
    vPosProj = vec4(worldPos, 1.0) * cViewProj;
    vScreenPos = GetScreenPosPreDiv(gl_Position);
    vFarRay = GetFarRay(gl_Position);
    vTexCoord = GetTexCoord(iTexCoord);
    vWorldPos = vec4(worldPos, GetDepth(gl_Position));

    #ifdef VERTEXCOLOR
        vColor = iColor;
    #endif

    #ifdef SP
        vParticleViewProjZ = gl_Position.z;
        //vParticleViewProjZ = gl_Position.z / gl_Position.w;
        //vParticleViewProjZ = GetDepth(gl_Position);
        //vParticleViewProjZ = gl_Position.w;
    #endif
}

void PS()
{
    // Get material diffuse albedo
    #ifdef DIFFMAP
        vec4 diffColor = cMatDiffColor * texture2D(sDiffMap, vTexCoord);
        #ifdef ALPHAMASK
            if (diffColor.a < 0.5)
                discard;
        #endif
    #else
        vec4 diffColor = cMatDiffColor;
    #endif

    #ifdef VERTEXCOLOR
        diffColor *= vColor;
    #endif

    // Get fog factor
    #ifdef HEIGHTFOG
        float fogFactor = GetHeightFogFactor(vWorldPos.w, vWorldPos.y);
    #else
        float fogFactor = GetFogFactor(vWorldPos.w);
    #endif

    #if defined(PREPASS)
        // Fill light pre-pass G-Buffer
        gl_FragData[0] = vec4(0.5, 0.5, 0.5, 1.0);
        gl_FragData[1] = vec4(EncodeDepth(vWorldPos.w), 0.0);
    #elif defined(DEFERRED)
        gl_FragData[0] = vec4(GetFog(diffColor.rgb, fogFactor), diffColor.a);
        gl_FragData[1] = vec4(0.0, 0.0, 0.0, 0.0);
        gl_FragData[2] = vec4(0.5, 0.5, 0.5, 1.0);
        gl_FragData[3] = vec4(EncodeDepth(vWorldPos.w), 0.0);
    #else
        #ifdef OUTMRT01
            // diffuse
            gl_FragData[0] = vec4(GetFog(diffColor.rgb, fogFactor), diffColor.a);
            gl_FragData[1] = vec4(vParticleViewProjZ, 0, 0, 1.0);
            // depth
            #ifdef SP
                //gl_FragData[1] = vec4(vParticleViewProjZ, 0.0, 0.0, 0.0);
            #else
                //gl_FragData[1] = vec4(0.0, 0.0, 0.0, 0.0);
            #endif
        #else
            // VS :: vScreenPos = GetScreenPosPreDiv(gl_Position);
            float sceneZ = texture2D(sDepthBuffer, vScreenPos).r;   // read depthstencil texture(readabledepth)
            float restoredSceneZ = ReconstructDepth(sceneZ);        // to 0..1 range
            vec3 sceneWorldPos = vFarRay * restoredSceneZ;          // restore worldpos of backgroud sceneZ
            vec4 sceneViewPos = vec4(sceneWorldPos, 1.0) * cProj;   // restore viewproj of backgroud sceneZ


            float scale = 2.0;
            // calc difference between sceneZ and particleZ
            float diffZ = (sceneViewPos.z - vParticleViewProjZ) * scale;
            //float diffZ = (sceneViewPos.w - vWorldPos.z) * scale;
            float input = clamp(diffZ, 0.0, 1.0);
            float contrastPower = 1.0;
            float output = 0.5 * pow(clamp(2*((input > 0.5) ? 1 - input : input), 0.0, 1.0), contrastPower);
            float weight = (input > 0.5) ? 1 - output : output;

            diffColor.a *= weight;

            gl_FragColor = vec4(GetFog(diffColor.rgb, fogFactor), diffColor.a);
        #endif
    #endif
}