1 files changed, 45 insertions, 15 deletions

diff --git a/engines/wintermute/base/gfx/osystem/base_render_osystem.h b/engines/wintermute/base/gfx/osystem/base_render_osystem.h
index 3cb0fa82a3..8996c8b2e8 100644
--- a/engines/wintermute/base/gfx/osystem/base_render_osystem.h
+++ b/engines/wintermute/base/gfx/osystem/base_render_osystem.h
@@ -33,15 +33,37 @@
 #include "common/rect.h"
 #include "graphics/surface.h"
 #include "common/list.h"
+#include "engines/wintermute/graphics/transform_struct.h"
 
 namespace Wintermute {
 class BaseSurfaceOSystem;
 class RenderTicket;
+/**
+ * A 2D-renderer implementation for WME.
+ * This renderer makes use of a "ticket"-system, where all draw-calls
+ * are stored as tickets until flip() is called, and compared against the tickets
+ * from last frame, to determine which calls were the same as last round
+ * (i.e. in the exact same order, with the exact same arguments), and thus
+ * figure out which parts of the screen need to be redrawn.
+ *
+ * Important concepts to handle here, is the ordered number of any ticket
+ * which is called the "drawNum", every frame this starts from scratch, and
+ * then the incoming tickets created from the draw-calls are checked to see whether
+ * they came before, on, or after the drawNum they had last frame. Everything else
+ * being equal, this information is then used to check whether the draw order changed,
+ * which will then create a need for redrawing, as we draw with an alpha-channel here.
+ *
+ * There is also a draw path that draws without tickets, for debugging purposes,
+ * as well as to accomodate situations with large enough amounts of draw calls,
+ * that there will be too much overhead involved with comparing the generated tickets.
+ */
 class BaseRenderOSystem : public BaseRenderer {
 public:
 	BaseRenderOSystem(BaseGame *inGame);
 	~BaseRenderOSystem();
 
+	typedef Common::List<RenderTicket *>::iterator RenderQueueIterator;
+
 	Common::String getName() const;
 
 	bool initRenderer(int width, int height, bool windowed) override;
@@ -50,17 +72,25 @@ public:
 	bool fill(byte r, byte g, byte b, Common::Rect *rect = nullptr) override;
 	Graphics::PixelFormat getPixelFormat() const override;
 	void fade(uint16 alpha) override;
-	void fadeToColor(byte r, byte g, byte b, byte a, Common::Rect *rect = nullptr) override;
+	void fadeToColor(byte r, byte g, byte b, byte a) override;
 
 	bool drawLine(int x1, int y1, int x2, int y2, uint32 color) override;
 
 	BaseImage *takeScreenshot() override;
 
-	void setAlphaMod(byte alpha);
-	void setColorMod(byte r, byte g, byte b);
 	void invalidateTicket(RenderTicket *renderTicket);
 	void invalidateTicketsFromSurface(BaseSurfaceOSystem *surf);
+	/**
+	 * Insert a new ticket into the queue, adding a dirty rect
+	 * @param renderTicket the ticket to be added.
+	 */
 	void drawFromTicket(RenderTicket *renderTicket);
+	/**
+	 * Re-insert an existing ticket into the queue, adding a dirty rect
+	 * out-of-order from last draw from the ticket.
+	 * @param ticket iterator pointing to the ticket to be added.
+	 */
+	void drawFromQueuedTicket(const RenderQueueIterator &ticket);
 
 	bool setViewport(int left, int top, int right, int bottom) override;
 	bool setViewport(Rect32 *rect) override { return BaseRenderer::setViewport(rect); }
@@ -80,24 +110,27 @@ public:
 	virtual bool startSpriteBatch() override;
 	virtual bool endSpriteBatch() override;
 	void endSaveLoad();
-	void drawSurface(BaseSurfaceOSystem *owner, const Graphics::Surface *surf, Common::Rect *srcRect, Common::Rect *dstRect, bool mirrorX, bool mirrorY, bool disableAlpha = false) ;
-	void repeatLastDraw(int offsetX, int offsetY, int numTimesX, int numTimesY);
+	void drawSurface(BaseSurfaceOSystem *owner, const Graphics::Surface *surf, Common::Rect *srcRect, Common::Rect *dstRect, TransformStruct &transform);
 	BaseSurface *createSurface() override;
 private:
-	void addDirtyRect(const Common::Rect &rect) ;
+	/**
+	 * Mark a specified rect of the screen as dirty.
+	 * @param rect the region to be marked as dirty
+	 */
+	void addDirtyRect(const Common::Rect &rect);
+	/**
+	 * Traverse the tickets that are dirty, and draw them
+	 */
 	void drawTickets();
 	// Non-dirty-rects:
 	void drawFromSurface(RenderTicket *ticket);
 	// Dirty-rects:
 	void drawFromSurface(RenderTicket *ticket, Common::Rect *dstRect, Common::Rect *clipRect);
-	typedef Common::List<RenderTicket *>::iterator RenderQueueIterator;
 	Common::Rect *_dirtyRect;
 	Common::List<RenderTicket *> _renderQueue;
-	RenderQueueIterator _lastAddedTicket;
-	RenderTicket *_previousTicket;
 
 	bool _needsFlip;
-	uint32 _drawNum;
+	RenderQueueIterator _lastFrameIter;
 	Common::Rect _renderRect;
 	Graphics::Surface *_renderSurface;
 	Graphics::Surface *_blankSurface;
@@ -108,17 +141,14 @@ private:
 	int _borderBottom;
 
 	bool _disableDirtyRects;
-	uint32 _tempDisableDirtyRects;
-	bool _spriteBatch;
-	uint32 _batchNum;
 	float _ratioX;
 	float _ratioY;
-	uint32 _colorMod;
 	uint32 _clearColor;
 
 	bool _skipThisFrame;
+	int _lastScreenChangeID; // previous value of OSystem::getScreenChangeID()
 };
 
-} // end of namespace Wintermute
+} // End of namespace Wintermute
 
 #endif