From fa4d310fb4d3ccdcf45b2f78e2a23126ec07f006 Mon Sep 17 00:00:00 2001
From: lolbot-iichan
Date: Thu, 27 Jun 2019 10:59:35 +0300
Subject: WINTERMUTE: Do not optimize out alpha blits on rotation

This fixes defect #10684: 1-pixel width sprite becomes a big rectangle
if rotation is applied.

Case was originally reproduced with FoxTail game for WME, then reduced
to testcase
https://github.com/tobiatesan/wme_testsuite/tree/master/time_test/packages
---
 engines/wintermute/base/gfx/osystem/base_surface_osystem.cpp | 3 ++-
 engines/wintermute/base/gfx/osystem/render_ticket.cpp        | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

(limited to 'engines/wintermute/base')

diff --git a/engines/wintermute/base/gfx/osystem/base_surface_osystem.cpp b/engines/wintermute/base/gfx/osystem/base_surface_osystem.cpp
index 4e33702504..140988267f 100644
--- a/engines/wintermute/base/gfx/osystem/base_surface_osystem.cpp
+++ b/engines/wintermute/base/gfx/osystem/base_surface_osystem.cpp
@@ -452,7 +452,8 @@ bool BaseSurfaceOSystem::drawSprite(int x, int y, Rect32 *rect, Rect32 *newRect,
 	// But no checking is in place for that yet.
 
 	// Optimize by not doing alpha-blits if we lack alpha
-	if (_alphaType == Graphics::ALPHA_OPAQUE && !transform._alphaDisable) {
+	// If angle is not 0, then transparent regions are added near the corners
+	if (_alphaType == Graphics::ALPHA_OPAQUE && transform._angle == 0) {
 		transform._alphaDisable = true;
 	}
 
diff --git a/engines/wintermute/base/gfx/osystem/render_ticket.cpp b/engines/wintermute/base/gfx/osystem/render_ticket.cpp
index acc9530684..e092e3cf17 100644
--- a/engines/wintermute/base/gfx/osystem/render_ticket.cpp
+++ b/engines/wintermute/base/gfx/osystem/render_ticket.cpp
@@ -117,6 +117,8 @@ void RenderTicket::drawToSurface(Graphics::Surface *_targetSurface) const {
 	if (_owner) {
 		if (_transform._alphaDisable) {
 			src.setAlphaMode(Graphics::ALPHA_OPAQUE);
+		} else if (_transform._angle) {
+			src.setAlphaMode(Graphics::ALPHA_FULL);
 		} else {
 			src.setAlphaMode(_owner->getAlphaType());
 		}
@@ -149,6 +151,8 @@ void RenderTicket::drawToSurface(Graphics::Surface *_targetSurface, Common::Rect
 	if (_owner) {
 		if (_transform._alphaDisable) {
 			src.setAlphaMode(Graphics::ALPHA_OPAQUE);
+		} else if (_transform._angle) {
+			src.setAlphaMode(Graphics::ALPHA_FULL);
 		} else {
 			src.setAlphaMode(_owner->getAlphaType());
 		}
-- 
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