Implemented the OSystem framebuffer API, as discussed on scummvm-devel. All changes are just fine, and won't cause any compile problems or regressions, despite the fact that I can't test most of the non-SDL backend changes, at an improbability level of two to the power of two hundred and seventy-six thousand to one against - possibly much higher. Anything you still can't cope with is therefore your own problem. Please relax.

svn-id: r27548

2 files changed, 21 insertions, 5 deletions

diff --git a/backends/platform/ds/arm9/source/osystem_ds.cpp b/backends/platform/ds/arm9/source/osystem_ds.cpp
index a804369b26..cad6ad6b78 100644
--- a/backends/platform/ds/arm9/source/osystem_ds.cpp
+++ b/backends/platform/ds/arm9/source/osystem_ds.cpp
@@ -474,8 +474,13 @@ Common::SaveFileManager* OSystem_DS::getSavefileManager()
 	}
 }
 
-bool OSystem_DS::grabRawScreen(Graphics::Surface* surf) {
-	surf->create(DS::getGameWidth(), DS::getGameHeight(), 1);
+Graphics::Surface *OSystem_DS::lockScreen() {
+	// For now, we create a full temporary screen surface, to which we copy the
+	// the screen content. Later unlockScreen will copy everything back.
+	// Not very nice nor efficient, but at least works, and is not worse
+	// than in the bad old times where we used grabRawScreen + copyRectToScreen.
+	
+	_framebuffer.create(DS::getGameWidth(), DS::getGameHeight(), 1);
 
 	// Ensure we copy using 16 bit quantities due to limitation of VRAM addressing
 	
@@ -486,11 +491,19 @@ bool OSystem_DS::grabRawScreen(Graphics::Surface* surf) {
 		DC_FlushRange(image + (y << 8), DS::getGameWidth());
 		for (int x = 0; x < DS::getGameWidth() >> 1; x++)
 		{
-			*(((u16 *) (surf->pixels)) + y * (DS::getGameWidth() >> 1) + x) = image[y << 8 + x];
+			*(((u16 *) (_framebuffer.pixels)) + y * (DS::getGameWidth() >> 1) + x) = image[y << 8 + x];
 		}
 	}
 
-	return true;
+	return &_framebuffer;
+}
+
+void OSystem_DS::unlockScreen() {
+	// Copy temp framebuffer back to screen
+	copyRectToScreen((byte *)_framebuffer.pixels, _framebuffer.pitch, 0, 0, _framebuffer.w, _framebuffer.h);
+
+	// Free memory
+	_framebuffer.free(); 
 }
 
 void OSystem_DS::setFocusRectangle(const Common::Rect& rect) {
diff --git a/backends/platform/ds/arm9/source/osystem_ds.h b/backends/platform/ds/arm9/source/osystem_ds.h
index 316f45bb6e..58b940af2c 100644
--- a/backends/platform/ds/arm9/source/osystem_ds.h
+++ b/backends/platform/ds/arm9/source/osystem_ds.h
@@ -53,6 +53,8 @@ public:
 	DSAudioMixer* _mixer;
 	DSTimerManager* _timer;
 
+	Graphics::Surface _framebuffer;
+
 	static OSystem_DS* _instance;
 	
 	typedef void (*SoundProc)(void *param, byte *buf, int len);
@@ -127,7 +129,8 @@ public:
 	void addEvent(Common::Event& e);
 	bool isEventQueueEmpty() { return queuePos == 0; }
 	
-	virtual bool grabRawScreen(Graphics::Surface* surf);
+	virtual Graphics::Surface *lockScreen();
+	virtual void unlockScreen();
 	
 	virtual void setFocusRectangle(const Common::Rect& rect);