fix: fix VR water

package/Shaders/Common/VR.hlsl

@@ -1,17 +1,21 @@
 /**
 Converts to the eye specific uv [0,1].
-In VR, texture buffers include the left and right eye in the same buffer. Flat only has a single camera for the entire width.
-This means the x value [0, .5] represents the left eye, and the x value (.5, 1] are the right eye.
-This returns the adjusted value
+In VR, texture buffers include the left and right eye in the same buffer. Flat
+only has a single camera for the entire width. This means the x value [0, .5]
+represents the left eye, and the x value (.5, 1] are the right eye. This returns
+the adjusted value
 @param uv - uv coords [0,1] to be encoded for VR
 @param a_eyeIndex The eyeIndex; 0 is left, 1 is right
+@param a_invertY Whether to invert the Y direction
 @returns uv with x coords adjusted for the VR texture buffer
 */
-float2 ConvertToStereoUV(float2 uv, uint a_eyeIndex)
+float2 ConvertToStereoUV(float2 uv, uint a_eyeIndex, uint a_invertY = 0)
 {
 #ifdef VR
 	// convert [0,1] to eye specific [0,.5] and [.5, 1] dependent on a_eyeIndex
 	uv.x = (uv.x + (float)a_eyeIndex) / 2;
+	if (a_invertY)
+		uv.y = 1 - uv.y;
 #endif
 	return uv;
 }
@@ -23,13 +27,16 @@ This means the x value [0, .5] represents the left eye, and the x value (.5, 1]
 This returns the adjusted value
 @param uv - eye specific uv coords [0,1]; if uv.x < 0.5, it's a left eye; otherwise right
 @param a_eyeIndex The eyeIndex; 0 is left, 1 is right
+@param a_invertY Whether to invert the Y direction
 @returns uv with x coords adjusted to full range for either left or right eye
 */
-float2 ConvertFromStereoUV(float2 uv, uint a_eyeIndex)
+float2 ConvertFromStereoUV(float2 uv, uint a_eyeIndex, uint a_invertY = 0)
 {
 #ifdef VR
 	// convert [0,.5] to [0, 1] and [.5, 1] to [0,1]
 	uv.x = 2 * uv.x - (float)a_eyeIndex;
+	if (a_invertY)
+		uv.y = 1 - uv.y;
 #endif
 	return uv;
 }
@@ -49,3 +56,23 @@ float2 ConvertToStereoSP(float2 screenPosition, uint a_eyeIndex, float2 a_resolu
 	screenPosition.x /= a_resolution.x;
 	return ConvertToStereoUV(screenPosition, a_eyeIndex) * a_resolution;
 }
+
+/**
+Calculates the depthMultiplier as used in water.hlsl
+
+VR appears to require use of CameraProjInverse and does not use projData
+@param a_uv uv coords to convert
+@param a_depth The calculated depth
+@param a_eyeIndex The eyeIndex; 0 is left, 1 is right
+@returns depthMultiplier
+*/
+float calculateDepthMultfromUV(float2 a_uv, float a_depth, uint a_eyeIndex = 0)
+{
+	float4 temp;
+	temp.xy = (a_uv * 2 - 1);
+	temp.z = a_depth;
+	temp.w = 1;
+	temp = mul(CameraProjInverse[a_eyeIndex], temp.xyzw);
+	temp.xyz /= temp.w;
+	return length(temp);
+}

package/Shaders/Water.hlsl

@@ -587,7 +587,11 @@ float3 GetWaterSpecularColor(PS_INPUT input, float3 normal, float3 viewDirection
 float GetScreenDepthWater(float2 screenPosition)
 {
 	float depth = DepthTex.Load(float3(screenPosition, 0)).x;
+#			if !defined(VR)
 	return (CameraData.w / (-depth * CameraData.z + CameraData.x));
+#			else   // VR appears to use hard coded values
+	return depth * 1.01 + -0.01;
+#			endif  // VR
 }
 #		endif
 
@@ -635,10 +639,11 @@ float3 GetWaterDiffuseColor(PS_INPUT input, float3 normal, float3 viewDirection,
 	float depth = GetScreenDepthWater(screenPosition);
 	float2 refractionScreenPosition = DynamicResolutionParams1.xy * (refractionUvRaw / VPOSOffset.xy);
 	float refractionDepth = GetScreenDepthWater(refractionScreenPosition);
-	float refractionDepthMul = length(
-		float3((refractionDepth * ((VPOSOffset.zw + refractionUvRaw) * 2 - 1)) /
-				   ProjData.xy,
-			refractionDepth));
+#				if !defined(VR)
+	float refractionDepthMul = length(float3((((VPOSOffset.zw + refractionUvRaw) * 2 - 1)) * refractionDepth / ProjData.xy, refractionDepth));
+#				else
+	float refractionDepthMul = calculateDepthMultfromUV(ConvertFromStereoUV(VPOSOffset.zw + refractionUvRaw, a_eyeIndex, 1), refractionDepth, a_eyeIndex);
+#				endif  //VR
 
 	float3 refractionDepthAdjustedViewDirection = -viewDirection * refractionDepthMul;
 	float refractionViewSurfaceAngle = dot(refractionDepthAdjustedViewDirection, ReflectPlane[a_eyeIndex].xyz);
@@ -737,8 +742,11 @@ PS_OUTPUT main(PS_INPUT input)
 	depth = GetScreenDepthWater(screenPosition);
 	float2 depthOffset =
 		DynamicResolutionParams2.xy * input.HPosition.xy * VPOSOffset.xy + VPOSOffset.zw;
+#				if !defined(VR)
 	float depthMul = length(float3((depthOffset * 2 - 1) * depth / ProjData.xy, depth));
-
+#				else
+	float depthMul = calculateDepthMultfromUV(ConvertFromStereoUV(depthOffset, eyeIndex, 1), depth, eyeIndex);
+#				endif  //VR
 	float3 depthAdjustedViewDirection = -viewDirection * depthMul;
 	float viewSurfaceAngle = dot(depthAdjustedViewDirection, ReflectPlane[eyeIndex].xyz);
 
@@ -756,12 +764,7 @@ PS_OUTPUT main(PS_INPUT input)
 #		elif defined(SPECULAR) && (NUM_SPECULAR_LIGHTS != 0)
 	float4 depthControl = float4(0, 0, 1, 0);
 #		else
-	// #			if !defined(VR)
 	float4 depthControl = DepthControl * (distanceMul - 1) + 1;
-// #			else
-// 	float4 VRDepthControl = DepthControl.zwxw;  // VR appears to move values around
-// 	float4 depthControl = VRDepthControl * (distanceMul - 1) + 1;
-// #			endif  // VR
 #		endif
 
 #		if defined(WATER_CAUSTICS)