WINTERMUTE: Partially fix rotoscale coordinate confusion

This fixes two issues:

* The rendering rectangle was not rotated, causing garbage to be
drawn if the rotated rectangle did not fully cover the unrotated
rectangle, or sprites to be clipped in the opposite case.

* The order of mirror/scale/rotation operations was inconsistent.
This commit does scaling first, followed by rotation. (This is only an
issue because scaling is specified separately in X and Y directions.)
For now only FIXMEs are added for mirroring.

1 files changed, 20 insertions, 6 deletions

diff --git a/engines/wintermute/graphics/transform_tools.cpp b/engines/wintermute/graphics/transform_tools.cpp
index ebf9092aaa..dc92cdbbfd 100644
--- a/engines/wintermute/graphics/transform_tools.cpp
+++ b/engines/wintermute/graphics/transform_tools.cpp
@@ -26,11 +26,23 @@
 
 namespace Wintermute {
 
-FloatPoint TransformTools::transformPoint(const FloatPoint &point, const float rotate, const Point32 &zoom, const bool mirrorX, const bool mirrorY) {
+FloatPoint TransformTools::transformPoint(FloatPoint point, const float rotate, const Point32 &zoom, const bool mirrorX, const bool mirrorY) {
 	float rotateRad = rotate * M_PI / 180.0f;
+	float x = point.x;
+	float y = point.y;
+	x = (x * zoom.x) / kDefaultZoomX;
+	y = (y * zoom.y) / kDefaultZoomY;
+#if 0
+	// TODO: Mirroring should be done before rotation, but the blitting
+	// code does the inverse, so we match that for now.
+	if (mirrorX)
+		x *= -1;
+	if (mirrorY)
+		y *= -1;
+#endif
 	FloatPoint newPoint;
-	newPoint.x = (point.x * cos(rotateRad) - point.y * sin(rotateRad)) * zoom.x / kDefaultZoomX;
-	newPoint.y = (point.x * sin(rotateRad) + point.y * cos(rotateRad)) * zoom.y / kDefaultZoomY;
+	newPoint.x = x * cos(rotateRad) - y * sin(rotateRad);
+	newPoint.y = x * sin(rotateRad) + y * cos(rotateRad);
 	if (mirrorX) {
 		newPoint.x *= -1;
 	}
@@ -58,10 +70,12 @@ Rect32 TransformTools::newRect(const Rect32 &oldRect, const TransformStruct &tra
 	float left = MIN(nw1.x, MIN(ne1.x, MIN(sw1.x, se1.x)));
 	float right = MAX(nw1.x, MAX(ne1.x, MAX(sw1.x, se1.x)));
 
-	Rect32 res;
-	newHotspot->y = (uint32)(-floor(top));
-	newHotspot->x = (uint32)(-floor(left));
+	if (newHotspot) {
+		newHotspot->y = (uint32)(-floor(top));
+		newHotspot->x = (uint32)(-floor(left));
+	}
 
+	Rect32 res;
 	res.top = (int32)(floor(top)) + transform._hotspot.y;
 	res.bottom = (int32)(ceil(bottom)) + transform._hotspot.y;
 	res.left = (int32)(floor(left)) + transform._hotspot.x;