image renderer quad interpolation

WickedEngine/imageHF.hlsli

@@ -9,12 +9,54 @@ TEXTURE2D(texture_background, float4, TEXSLOT_IMAGE_BACKGROUND);
 
 SAMPLERSTATE(Sampler, SSLOT_ONDEMAND0);
 
+float Wedge2D(float2 v, float2 w)
+{
+	return v.x * w.y - v.y * w.x;
+}
+
 struct VertextoPixel
 {
 	float4 pos : SV_POSITION;
-	float2 uv0 : TEXCOORD0;
-	float2 uv1 : TEXCOORD1;
+	float2 q : TEXCOORD3;
+	float2 b1 : TEXCOORD4;
+	float2 b2 : TEXCOORD5;
+	float2 b3 : TEXCOORD6;
 	float4 uv_screen : TEXCOORD2;
+
+	float4 compute_uvs()
+	{
+		// Quad interpolation: http://reedbeta.com/blog/quadrilateral-interpolation-part-2/
+
+		// Set up quadratic formula
+		float A = Wedge2D(b2, b3);
+		float B = Wedge2D(b3, q) - Wedge2D(b1, b2);
+		float C = Wedge2D(b1, q);
+
+		// Solve for v
+		float2 uv;
+		if (abs(A) < 0.001)
+		{
+			// Linear form
+			uv.y = -C / B;
+		}
+		else
+		{
+			// Quadratic form. Take positive root for CCW winding with V-up
+			float discrim = B * B - 4 * A * C;
+			uv.y = 0.5 * (-B + sqrt(discrim)) / A;
+		}
+
+		// Solve for u, using largest-magnitude component
+		float2 denom = b1 + uv.y * b3;
+		if (abs(denom.x) > abs(denom.y))
+			uv.x = (q.x - b2.x * uv.y) / denom.x;
+		else
+			uv.x = (q.y - b2.y * uv.y) / denom.y;
+
+		float2 uv0 = uv * xTexMulAdd.xy + xTexMulAdd.zw;
+		float2 uv1 = uv * xTexMulAdd2.xy + xTexMulAdd2.zw;
+		return float4(uv0, uv1);
+	}
 };
 
 #endif // WI_IMAGE_HF

WickedEngine/imagePS.hlsl

@@ -2,7 +2,8 @@
 
 float4 main(VertextoPixel input) : SV_TARGET
 {
-	float4 color = texture_base.Sample(Sampler, input.uv0) * xColor;
+	float4 uvsets = input.compute_uvs();
+	float4 color = texture_base.Sample(Sampler, uvsets.xy) * xColor;
 
 	return color;
-}
+}

WickedEngine/imagePS_backgroundblur.hlsl

@@ -2,7 +2,8 @@
 
 float4 main(VertextoPixel input) : SV_TARGET
 {
-	float4 color = texture_base.Sample(Sampler, input.uv0) * xColor;
+	float4 uvsets = input.compute_uvs();
+	float4 color = texture_base.Sample(Sampler, uvsets.xy) * xColor;
 	float3 background = texture_background.Sample(Sampler, (input.uv_screen.xy * float2(0.5f, -0.5f) + 0.5f) / input.uv_screen.w).rgb;
 
 	return float4(lerp(background, color.rgb, color.a), 1);

WickedEngine/imagePS_backgroundblur_masked.hlsl

@@ -2,9 +2,10 @@
 
 float4 main(VertextoPixel input) : SV_TARGET
 {
-	float4 color = texture_base.Sample(Sampler, input.uv0) * xColor;
+	float4 uvsets = input.compute_uvs();
+	float4 color = texture_base.Sample(Sampler, uvsets.xy) * xColor;
 	float3 background = texture_background.Sample(Sampler, (input.uv_screen.xy * float2(0.5f, -0.5f) + 0.5f) / input.uv_screen.w).rgb;
-	float4 mask = texture_mask.Sample(Sampler, input.uv1);
+	float4 mask = texture_mask.Sample(Sampler, uvsets.zw);
 	color *= mask;
 
 	return float4(lerp(background, color.rgb, color.a), mask.a);

WickedEngine/imagePS_masked.hlsl

@@ -2,9 +2,10 @@
 
 float4 main(VertextoPixel input) : SV_TARGET
 {
-	float4 color = texture_base.Sample(Sampler, input.uv0) * xColor;
+	float4 uvsets = input.compute_uvs();
+	float4 color = texture_base.Sample(Sampler, uvsets.xy) * xColor;
 	
-	color *= texture_mask.Sample(Sampler, input.uv1);
+	color *= texture_mask.Sample(Sampler, uvsets.zw);
 
 	return color;
-}
+}

WickedEngine/imagePS_separatenormalmap.hlsl

@@ -2,11 +2,12 @@
 
 float4 main(VertextoPixel input) : SV_TARGET
 {
-	float4 color = texture_base.Sample(Sampler, input.uv0);
+	float4 uvsets = input.compute_uvs();
+	float4 color = texture_base.Sample(Sampler, uvsets.xy);
 
 	color = 2 * color - 1;
 
 	color *= xColor;
 
 	return color;
-}
+}

WickedEngine/imagePS_separatenormalmap_bicubic.hlsl

@@ -2,11 +2,12 @@
 
 float4 main(VertextoPixel input) : SV_TARGET
 {
-	float4 color = SampleTextureCatmullRom(texture_base, Sampler, input.uv0);
+	float4 uvsets = input.compute_uvs();
+	float4 color = SampleTextureCatmullRom(texture_base, Sampler, uvsets.xy);
 
 	color = 2 * color - 1;
 
 	color *= xColor;
 
 	return color;
-}
+}

WickedEngine/imageVS.hlsl

@@ -12,13 +12,14 @@ VertextoPixel main(uint vI : SV_VERTEXID)
 	//	3--4
 
 	Out.pos = xCorners[vI];
-
-	Out.uv0 = float2(vI % 2, vI % 4 / 2);
-	Out.uv1 = Out.uv0;
-	Out.uv0 = Out.uv0 * xTexMulAdd.xy + xTexMulAdd.zw;
-	Out.uv1 = Out.uv1 * xTexMulAdd2.xy + xTexMulAdd2.zw;
 	Out.uv_screen = Out.pos;
 
+	// Set up inverse bilinear interpolation
+	Out.q = Out.pos.xy - xCorners[0].xy;
+	Out.b1 = xCorners[1].xy - xCorners[0].xy;
+	Out.b2 = xCorners[2].xy - xCorners[0].xy;
+	Out.b3 = xCorners[0].xy - xCorners[1].xy - xCorners[2].xy + xCorners[3].xy;
+
 	return Out;
 }
 

WickedEngine/wiVersion.cpp

@@ -9,7 +9,7 @@ namespace wiVersion
 	// minor features, major updates, breaking compatibility changes
 	const int minor = 53;
 	// minor bug fixes, alterations, refactors, updates
-	const int revision = 5;
+	const int revision = 6;
 
 	const std::string version_string = std::to_string(major) + "." + std::to_string(minor) + "." + std::to_string(revision);