From a2b99e23d26dbf9ee8073402fbb262cce86b4f52 Mon Sep 17 00:00:00 2001
From: "Unknown W. Brackets" <checkins@unknownbrackets.org>
Date: Wed, 13 May 2020 08:39:50 -0700
Subject: [PATCH] GPU: Handle buffer overhead in postshader uniforms.

Framebuffers may be temporarily larger than the estimated width, because
we estimate different sizes for them and resizing is expensive.

This moves accounting for that to texelDelta instead of pixelDelta.
---
 GPU/Common/FramebufferCommon.cpp | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/GPU/Common/FramebufferCommon.cpp b/GPU/Common/FramebufferCommon.cpp
index 0bd3f03985..15af360342 100644
--- a/GPU/Common/FramebufferCommon.cpp
+++ b/GPU/Common/FramebufferCommon.cpp
@@ -799,7 +799,7 @@ void FramebufferManagerCommon::DrawFramebufferToOutput(const u8 *srcPixels, GEBu
 		// Might've changed if the shader was just changed to Off.
 		if (usePostShader_) {
 			PostShaderUniforms uniforms{};
-			CalculatePostShaderUniforms(480, 272, renderWidth_, renderHeight_, &uniforms);
+			CalculatePostShaderUniforms(512, 272, renderWidth_, renderHeight_, &uniforms);
 			BindPostShader(uniforms);
 		} else {
 			Bind2DShader();
@@ -1015,7 +1015,9 @@ void FramebufferManagerCommon::CopyDisplayToOutput(bool reallyDirty) {
 			SetViewport2D(0, 0, fbo_w, fbo_h);
 			draw_->SetScissorRect(0, 0, fbo_w, fbo_h);
 			PostShaderUniforms uniforms{};
-			CalculatePostShaderUniforms(vfb->bufferWidth, vfb->bufferHeight, renderWidth_, renderHeight_, &uniforms);
+			int actualWidth = (vfb->bufferWidth * vfb->renderWidth) / vfb->width;
+			int actualHeight = (vfb->bufferHeight * vfb->renderHeight) / vfb->height;
+			CalculatePostShaderUniforms(actualWidth, actualHeight, renderWidth_, renderHeight_, &uniforms);
 			BindPostShader(uniforms);
 			DrawTextureFlags flags = g_Config.iBufFilter == SCALE_LINEAR ? DRAWTEX_LINEAR : DRAWTEX_NEAREST;
 			DrawActiveTexture(0, 0, fbo_w, fbo_h, fbo_w, fbo_h, 0.0f, 0.0f, 1.0f, 1.0f, ROTATION_LOCKED_HORIZONTAL, flags);
@@ -1064,7 +1066,9 @@ void FramebufferManagerCommon::CopyDisplayToOutput(bool reallyDirty) {
 			flags = flags | DRAWTEX_TO_BACKBUFFER;
 
 			PostShaderUniforms uniforms{};
-			CalculatePostShaderUniforms(vfb->bufferWidth, vfb->bufferHeight, vfb->renderWidth, vfb->renderHeight, &uniforms);
+			int actualWidth = (vfb->bufferWidth * vfb->renderWidth) / vfb->width;
+			int actualHeight = (vfb->bufferHeight * vfb->renderHeight) / vfb->height;
+			CalculatePostShaderUniforms(actualWidth, actualHeight, vfb->renderWidth, vfb->renderHeight, &uniforms);
 			BindPostShader(uniforms);
 			if (g_Config.bEnableCardboardVR) {
 				// Left Eye Image
@@ -1835,15 +1839,15 @@ void FramebufferManagerCommon::Resized() {
 }
 
 void FramebufferManagerCommon::CalculatePostShaderUniforms(int bufferWidth, int bufferHeight, int renderWidth, int renderHeight, PostShaderUniforms *uniforms) {
-	float u_delta = 1.0f / renderWidth;
-	float v_delta = 1.0f / renderHeight;
-	float u_pixel_delta = u_delta;
-	float v_pixel_delta = v_delta;
+	float u_delta = 1.0f / bufferWidth;
+	float v_delta = 1.0f / bufferHeight;
+	float u_pixel_delta = 1.0 / renderWidth;
+	float v_pixel_delta = 1.0 / renderHeight;
 	if (postShaderAtOutputResolution_) {
 		float x, y, w, h;
 		CenterDisplayOutputRect(&x, &y, &w, &h, 480.0f, 272.0f, (float)pixelWidth_, (float)pixelHeight_, ROTATION_LOCKED_HORIZONTAL);
-		u_pixel_delta = (1.0f / w) * (480.0f / bufferWidth);
-		v_pixel_delta = (1.0f / h) * (272.0f / bufferHeight);
+		u_pixel_delta = 1.0f / w;
+		v_pixel_delta = 1.0f / h;
 	}
 	int flipCount = __DisplayGetFlipCount();
 	int vCount = __DisplayGetVCount();