Point Light with Shadow Casting

[Alex Ros]

A question just for a check. Is there a possibility to rescript (or whatever is the right term) Point Light in a way it could cast dynamic shadows similar to Spot Light? I am not sure if it's possible. If this feature (dynamic shadows) is hard-coded in some of engine .dll's surely it would be nearly impossible to make anything or extremely hard because it would require reassembling.

But at the same time there a shader file ...core\shaders\deferred_light_frag.glsl and maybe it's possible to make new strings for some kinda new type of light Point Shadow Light.

Here's a copypast of some strings from deferred_light_frag.glsl shader file:

Code: (Select All)

@ifdef LightType_Spot
    @ifdef UseGobo || UseShadowMap
        uniform mat4 a_mtxSpotViewProj;
    @endif
        
    @ifdef UseGobo
    @else
        uniform float afOneMinusCosHalfSpotFOV;
        uniform vec3 avLightForward;
    @endif
    
    @ifdef UseShadowMap
        @ifdef ShadowMapQuality_Low
        @else
            uniform vec2 avShadowMapOffsetMul;
        @endif
    @endif
//Point specfics
@else
    @ifdef UseGobo
        uniform mat4 a_mtxInvViewRotation;
    @endif
@endif

and here's another part which I presume is code of shadows themselves:

Code: (Select All)

    /////////////////////////////////
    // Caclulate shadow (if any)
    
    @ifdef UseShadowMap && LightType_Spot
        
        @ifdef UseGobo
        @else
            vec4 vProjectedUv = a_mtxSpotViewProj * vec4(vPos,1.0);
        @endif
            
        ////////////////////////
        // No Smoothing
        @ifdef ShadowMapQuality_Low
        
            fAttenuatuion *= shadow2DProj(aShadowMap, vProjectedUv).x;
                    
        ///////////////////////
        // Smoothing
        @else    
            //Set up variables
            float fShadowSum = 0;
            float fJitterZ =0;
            vec2 vScreenJitterCoord = gl_FragCoord.xy * $ShadowJitterLookupMul;
            
            vScreenJitterCoord.y = fract(vScreenJitterCoord.y);     //Make sure the coord is in 0 - 1 range
            vScreenJitterCoord.y *= 1.0 / $ShadowJitterSamplesDiv2;     //Access only first texture piece
                        
                
            ////////////////
            // Shader Model 3, Dynamic Branching available
            @ifdef ShaderModel_4
                ////////////////
                // Cheap pre-test
                //  Note1: division must occur when getting samples else gfx card gets angry.)
                //  Note2: It _must_ be division! doing sample * 1/8 will fail!!
                for(int i=0; i<2.0; i++)
                {
                    vec2 vJitterLookupCoord = vec2(vScreenJitterCoord.x, vScreenJitterCoord.y + fJitterZ);
                    
                    vec4 vOffset = texture2D(aShadowOffsetMap, vJitterLookupCoord) *2.0-1.0;
                                    
                    fShadowSum += ShadowOffsetLookup(aShadowMap, vProjectedUv, vec2(vOffset.xy) * avShadowMapOffsetMul ) / 4.0;
                    fShadowSum += ShadowOffsetLookup(aShadowMap, vProjectedUv, vec2(vOffset.zw) * avShadowMapOffsetMul ) / 4.0;
                                
                    fJitterZ += 1.0 / $ShadowJitterSamplesDiv2;
                }
                
                ////////////////
                // Check if in penumbra
                if( (fShadowSum-1.0) * fShadowSum * fLDotN != 0)
                {     
                    //Multiply, so the X presamples only affect their part (X/all_samples) of samples taken.
                    fShadowSum *= 4.0 / $ShadowJitterSamples;
                                
                    ////////////////
                    // Fullscale filtering
                    for(int i=0; i<$ShadowJitterSamplesDiv2-2.0; i++)
                    {
                        vec2 vJitterLookupCoord = vec2(vScreenJitterCoord.x, vScreenJitterCoord.y + fJitterZ); //Not that coords are 0-1!
                    
                        vec4 vOffset = texture2D(aShadowOffsetMap, vJitterLookupCoord) *2.0 - 1.0;
                                                            
                        fShadowSum += ShadowOffsetLookup(aShadowMap, vProjectedUv, vec2(vOffset.xy) * avShadowMapOffsetMul ) / $ShadowJitterSamples;
                        fShadowSum += ShadowOffsetLookup(aShadowMap, vProjectedUv, vec2(vOffset.zw) * avShadowMapOffsetMul ) / $ShadowJitterSamples;
                        
                        fJitterZ += 1.0 / $ShadowJitterSamplesDiv2;
                    }
                    
                    //vDiffuse.xyz = vec3(0,0,1);
                }
                /*else
                {
                    if(fShadowSum>0.5)     vDiffuse.xyz = vec3(1,0,0);    
                    else             vDiffuse.xyz = vec3(0,1,0);
                    
                    //fAttenuatuion *= fShadowSum;    
                }*/
            /////////////////////
            // No Dynamic Branching
            @else
                for(int i=0; i<$ShadowJitterSamplesDiv2; i++)
                {
                    vec2 vJitterLookupCoord = vec2(vScreenJitterCoord.x, vScreenJitterCoord.y + fJitterZ);
                    
                    vec4 vOffset = texture2D(aShadowOffsetMap, vJitterLookupCoord) *2.0 - 1.0;
                    
                    fShadowSum += ShadowOffsetLookup(aShadowMap, vProjectedUv, vec2(vOffset.xy) * avShadowMapOffsetMul );
                    fShadowSum += ShadowOffsetLookup(aShadowMap, vProjectedUv, vec2(vOffset.zw) * avShadowMapOffsetMul );
                                
                    fJitterZ += 1.0 / $ShadowJitterSamplesDiv2;
                }
                
                fShadowSum /= $ShadowJitterSamples;
            @endif
            
            
            /////////////////////
            // Add shadow sum to attenuation
            fAttenuatuion *= fShadowSum;
        @endif
        
    
    @endif

I am not a scripter and that's why I am asking for help or just an advice. I do have some knowledge of scripts, at least I can understand what is what and what for. But... anyway if anybody can help or advice something, thanks in advance! At the same time I am sure if such an "upgrade" of HPL2 Lights is possible and could be done by someone, than it would be very useful for everybody. I mean everybody could be thankful, not just me.