Attachment 37980 Details for Bug 29675 – shader from RenderFeatTest32

shader from RenderFeatTest32

deferred_ssao_render_frag.glsl (text/plain), 3.90 KB, created by Sven Arvidsson on 2010-08-19 06:05:09 UTC

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Creator: Sven Arvidsson

Created: 2010-08-19 06:05:09 UTC

Size: 3.90 KB

patch

obsolete

>#version 120
>
>#extension GL_ARB_texture_rectangle : enable
>
>uniform float afFarPlane;
>
>uniform float afScatterLengthMul;
>uniform vec2 avScatterLengthLimits;
>uniform float afDepthDiffMul;
>uniform float afSkipEdgeLimit;
>
>uniform vec2 avScreenSize;
>
>uniform sampler2DRect depthMap;
>@define sampler_depthMap 0
>
>uniform sampler2D scatterDisk;
>@define sampler_scatterDisk 1
>
>void main()
>{
>	///////////////
>	// This is the core depth that we compare to
>	float fCoreDepth = texture2DRect(depthMap, gl_TexCoord[0].xy).x;
>	
>	
>	//Have a max limit on the length, or else there will be major slowdowns when many objects are upfront.
>	//Multiply with height (y) since width varies with aspect!
>	//Also added a min length to make stuff darker at a distance to avoid flickering.
>	float fScatterLength = clamp(afScatterLengthMul / (fCoreDepth * afFarPlane), avScatterLengthLimits.x, avScatterLengthLimits.y) * avScreenSize.y;	
>	float fScatterDiskZ =0.0;
>	
>	vec2 vScreenScatterCoord = (gl_FragCoord.xy) * 1.0 / 4.0; //4 = size of scatter texture, and this is to get a 1-1 pixel-texture usage.
>	
>	vScreenScatterCoord.y = fract(vScreenScatterCoord.y);	 //Make sure the coord is in 0 - 1 range
>	vScreenScatterCoord.y *= 1.0 / $SampleNumDiv2;		//Access only first texture piece
>		
>	///////////////////////////////////////////
>	// Depth enhance
>	float fOccSum =0.0;
>	float fFarPlaneMulDepthDiffMul = afFarPlane * afDepthDiffMul;
>	
>	//////////////////////////////////////////
>	// Go through the samples, 4 at a time!
>	for(int i=0; i<$SampleNumDiv2 / 2; i++)
>	{
>		//Get the scatter coordinates (used to get the randomized postion for each sampling)
>		vec2 vScatterLookupCoord1 = vec2(vScreenScatterCoord.x, vScreenScatterCoord.y + fScatterDiskZ*4.0);
>					
>		vec4 vOffset1 = (texture2D(scatterDisk, vScatterLookupCoord1) *2.0 - 1.0)  * fScatterLength;
>		
>		//Look up the depth at the random samples. Notice that x-z and y-w are each others opposites! (important for extra polation below!)
>		vec4 vDepth = vec4(	texture2DRect(depthMap, gl_TexCoord[0].xy + vOffset1.xy).x,
>					texture2DRect(depthMap, gl_TexCoord[0].xy + vOffset1.zw).x,
>					texture2DRect(depthMap, gl_TexCoord[0].xy - vOffset1.xy).x,
>					texture2DRect(depthMap, gl_TexCoord[0].xy - vOffset1.zw).x);
>		
>		//The z difference in world coords multplied with DepthDiffMul
>		vec4 vDiff = (fCoreDepth - vDepth) * fFarPlaneMulDepthDiffMul;
>		
>		//This this test to remove halos. If a certain limit is reached, then the negative value of the opposite difference is used. 
>		//This acts as an extrapolation "behind" the blocking geometry)
>		vec4 vDiffSwap = -vDiff.zwxy;
>		/*if(vDiff.x > afSkipEdgeLimit) vDiff.x = vDiffSwap.x;
>		if(vDiff.y > afSkipEdgeLimit) vDiff.y = vDiffSwap.y;
>		if(vDiff.z > afSkipEdgeLimit) vDiff.z = vDiffSwap.z;
>		if(vDiff.w > afSkipEdgeLimit) vDiff.w = vDiffSwap.w;*/
>		
>		//Invert the difference (so positive means uncovered) and then give unocvered values a slight advantage	
>		//Also sett a max negative value (limits how much covered areas can affect.
>		vDiff = max(vec4(1) - vDiff, -0.7);
>		
>		//Caclculate the occulsion value, (the squaring makes sharper dark areas)
>		vec4 vOcc = min(vDiff*vDiff, 1.0f);
>		
>		fOccSum += dot(vOcc,vec4(1.0));
>		
>		//Change the z coord for random coord look up (so new values are used on next iteration)
>		fScatterDiskZ += (1.0 / $SampleNumDiv2) * 2.0;
>	}
>	
>	float fOcc = fOccSum / (2.0 * $SampleNumDiv2);
>	
>	gl_FragColor.xyz = vec3(fOcc * fOcc);
>	
>	//gl_FragColor.x = smoothstep(0.0, 1.0, fOccDepth);
>	//gl_FragColor.x = mod(vScreenScatterCoord.x, 1.0);
>	
>	
>	//gl_FragColor.x = pow(fOcc, 1.25);
>	//gl_FragColor.x = smoothstep(0.0, 1.0, fOcc);	//Use this to darken dark spots and make very brigth stuff white. This removes artefacts without making the scene too bright.
>	
>	//vec3 vScatterLookupCoord = vec3(vScreenScatterCoord, 0);
>	//gl_FragColor.x = texture3D(scatterDisk, vScatterLookupCoord).x;
>}
>

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Attachments on bug 29675: 37980

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