Remove unused viewportHeight field

Bug: cleanup
Change-Id: I35040cdd0451b8d6b8063f4f3a78915eb97ceae4
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/69670
Tested-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
diff --git a/src/Device/Renderer.cpp b/src/Device/Renderer.cpp
index bf6d20c..12e4027 100644
--- a/src/Device/Renderer.cpp
+++ b/src/Device/Renderer.cpp
@@ -310,7 +310,6 @@
 		data->Y0xF = Y0 * subPixF - subPixF / 2;
 		data->halfPixelX = 0.5f / W;
 		data->halfPixelY = 0.5f / H;
-		data->viewportHeight = abs(viewport.height);
 		data->depthRange = Z;
 		data->depthNear = N;
 		data->constantDepthBias = preRasterizationState.getConstantDepthBias();
diff --git a/src/Device/Renderer.hpp b/src/Device/Renderer.hpp
index a2ea92d..284a6e9 100644
--- a/src/Device/Renderer.hpp
+++ b/src/Device/Renderer.hpp
@@ -80,7 +80,6 @@
 	float Y0xF;
 	float halfPixelX;
 	float halfPixelY;
-	float viewportHeight;
 	float depthRange;
 	float depthNear;
 	float minimumResolvableDepthDifference;