Added function to encapsulate/protect manipulation of background.

svn-id: r30441

3 files changed, 17 insertions, 8 deletions

diff --git a/engines/parallaction/exec_ns.cpp b/engines/parallaction/exec_ns.cpp
index f2ee015498..91a8809070 100644
--- a/engines/parallaction/exec_ns.cpp
+++ b/engines/parallaction/exec_ns.cpp
@@ -133,15 +133,9 @@ DECLARE_INSTRUCTION_OPCODE(put) {
 
 	int16 x = inst->_opA.getRValue();
 	int16 y = inst->_opB.getRValue();
+	bool mask = (inst->_flags & kInstMaskedPut) == kInstMaskedPut;
 
-	if (inst->_flags & kInstMaskedPut) {
-		uint16 z = _gfx->queryMask(y);
-		_gfx->blitCnv(&v18, x, y, z, Gfx::kBitBack);
-		_gfx->blitCnv(&v18, x, y, z, Gfx::kBit2);
-	} else {
-		_gfx->flatBlitCnv(&v18, x, y, Gfx::kBitBack);
-		_gfx->flatBlitCnv(&v18, x, y, Gfx::kBit2);
-	}
+	_gfx->patchBackground(v18, x, y, mask);
 }
 
 DECLARE_INSTRUCTION_OPCODE(null) {
diff --git a/engines/parallaction/graphics.cpp b/engines/parallaction/graphics.cpp
index 595c264c59..65938fc176 100644
--- a/engines/parallaction/graphics.cpp
+++ b/engines/parallaction/graphics.cpp
@@ -394,6 +394,19 @@ void Gfx::copyScreen(Gfx::Buffers srcbuffer, Gfx::Buffers dstbuffer) {
 	return;
 }
 
+void Gfx::patchBackground(Graphics::Surface &surf, int16 x, int16 y, bool mask) {
+
+	if (mask) {
+		uint16 z = queryMask(y);
+		blitCnv(&surf, x, y, z, kBitBack);
+		blitCnv(&surf, x, y, z, kBit2);
+	} else {
+		flatBlitCnv(&surf, x, y, kBitBack);
+		flatBlitCnv(&surf, x, y, kBit2);
+	}
+
+}
+
 void Gfx::floodFill(Gfx::Buffers buffer, const Common::Rect& r, byte color) {
 
 	byte *d = (byte*)_buffers[buffer]->getBasePtr(r.left, r.top);
diff --git a/engines/parallaction/graphics.h b/engines/parallaction/graphics.h
index a9af5e85ab..7bfaef624d 100644
--- a/engines/parallaction/graphics.h
+++ b/engines/parallaction/graphics.h
@@ -274,6 +274,8 @@ public:
 	void freeLabels();
 
 	// cut/paste
+	void patchBackground(Graphics::Surface &surf, int16 x, int16 y, bool mask = false);
+
 	void flatBlitCnv(Graphics::Surface *cnv, int16 x, int16 y, Gfx::Buffers buffer);
 	void flatBlitCnv(Frames *cnv, uint16 frame, int16 x, int16 y, Gfx::Buffers buffer);
 	void blitCnv(Graphics::Surface *cnv, int16 x, int16 y, uint16 z, Gfx::Buffers buffer);