Merge pull request #8168 from hrydgard/viewport-vertical-fix

Fix viewport vertical positioning, fixing #8165.

GPU/Common/SoftwareTransformCommon.cpp

@@ -471,7 +471,7 @@ void SoftwareTransform(
 		if (!throughmode) {
 			memcpy(&flippedMatrix, gstate.projMatrix, 16 * sizeof(float));
 
-			const bool invertedY = useBufferedRendering ? (gstate_c.vpHeight > 0) : (gstate_c.vpHeight < 0);
+			const bool invertedY = useBufferedRendering ? (gstate_c.vpHeight < 0) : (gstate_c.vpHeight > 0);
 			if (invertedY) {
 				flippedMatrix[1] = -flippedMatrix[1];
 				flippedMatrix[5] = -flippedMatrix[5];

GPU/Directx9/TransformPipelineDX9.cpp

@@ -832,7 +832,7 @@ rotateVBO:
 		SoftwareTransform(
 			prim, decoded, indexGen.VertexCount(),
 			dec_->VertexType(), inds, GE_VTYPE_IDX_16BIT, dec_->GetDecVtxFmt(),
-			maxIndex, framebufferManager_, textureCache_, transformed, transformedExpanded, drawBuffer, numTrans, drawIndexed, &result, -1.0f);
+			maxIndex, framebufferManager_, textureCache_, transformed, transformedExpanded, drawBuffer, numTrans, drawIndexed, &result, 1.0f);
 
 		ApplyDrawStateLate();
 		vshader = shaderManager_->ApplyShader(prim, lastVType_);

GPU/GLES/ShaderManager.cpp

@@ -410,7 +410,7 @@ void LinkedShader::UpdateUniforms(u32 vertType) {
 
 		bool useBufferedRendering = g_Config.iRenderingMode != FB_NON_BUFFERED_MODE;
 
-		const bool invertedY = useBufferedRendering ? (gstate_c.vpHeight > 0) : (gstate_c.vpHeight < 0);
+		const bool invertedY = useBufferedRendering ? (gstate_c.vpHeight < 0) : (gstate_c.vpHeight > 0);
 		if (invertedY) {
 			flippedMatrix[1] = -flippedMatrix[1];
 			flippedMatrix[5] = -flippedMatrix[5];

GPU/GLES/StateMapping.cpp

@@ -835,22 +835,19 @@ void TransformDrawEngine::ApplyDrawState(int prim) {
 
 		// This means that to get the analogue glViewport we must:
 		float vpX0 = vpXCenter - offsetX - fabsf(vpXScale);
-		float vpY0 = vpYCenter - offsetY + fabsf(vpYScale);   // Need to account for sign of Y
+		float vpY0 = vpYCenter - offsetY - fabsf(vpYScale);   // Need to account for sign of Y
 		gstate_c.vpWidth = vpXScale * 2.0f;
-		gstate_c.vpHeight = -vpYScale * 2.0f;
+		gstate_c.vpHeight = vpYScale * 2.0f;
 
 		float vpWidth = fabsf(gstate_c.vpWidth);
 		float vpHeight = fabsf(gstate_c.vpHeight);
 
+		// This multiplication should probably be done after viewport clipping. Would let us very slightly simplify the clipping logic?
 		vpX0 *= renderWidthFactor;
 		vpY0 *= renderHeightFactor;
 		vpWidth *= renderWidthFactor;
 		vpHeight *= renderHeightFactor;
 
-		// Flip vpY0 to match the OpenGL coordinate system.
-		// TODO: This makes no sense anymore, in "flipped space".
-		vpY0 = renderHeight - vpY0;
-
 		// We used to apply the viewport here via glstate, but there are limits which vary by driver.
 		// This may mean some games won't work, or at least won't work at higher render resolutions.
 		// So we apply it in the shader instead.
@@ -882,7 +879,7 @@ void TransformDrawEngine::ApplyDrawState(int prim) {
 			float overageTop = std::max(-top, 0.0f);
 			float overageBottom = std::max(bottom - renderHeight, 0.0f);
 			// Our center drifted by the difference in overages.
-			float drift = overageTop - overageBottom;
+			float drift = overageBottom - overageTop;
 
 			top += overageTop;
 			bottom -= overageBottom;