2 files changed, 25 insertions, 9 deletions

diff --git a/engines/zvision/render_manager.cpp b/engines/zvision/render_manager.cpp
index 7edbf52039..4fd1a83088 100644
--- a/engines/zvision/render_manager.cpp
+++ b/engines/zvision/render_manager.cpp
@@ -63,14 +63,14 @@ void RenderManager::updateScreen(bool isConsoleActive) {
 
 void RenderManager::renderSubRectToScreen(uint16 *buffer, uint32 imageWidth, uint32 imageHeight, uint32 horizontalPitch, uint32 destinationX, uint32 destinationY, Common::Rect subRectangle) {
 	// Panoramas are transposed
-	// The actual data is transposed in the RenderTable lookup
+	// The actual data is transposed in mutateImage
 	if (_renderTable.getRenderState() == RenderTable::PANORAMA || _renderTable.getRenderState() == RenderTable::TILT) {
 		uint32 temp = imageHeight;
 		imageHeight = imageWidth;
 		imageWidth = temp;
 	}
 	
-	// Check if we truly want a subRect of the image
+	// If subRect is empty, use the entire image
 	if (subRectangle.isEmpty())
 		subRectangle = Common::Rect(imageWidth, imageHeight);
 
@@ -107,19 +107,23 @@ void RenderManager::renderImageToScreen(const Common::String &fileName, uint32 d
 		return;
 	}
 
+	renderImageToScreen(file, destinationX, destinationY, subRectangle);
+}
+
+void RenderManager::renderImageToScreen(Common::SeekableReadStream &stream, uint32 destinationX, uint32 destinationY, Common::Rect subRectangle) {
 	// Read the magic number
 	// Some files are true TGA, while others are TGZ
 	uint32 fileType;
-	fileType = file.readUint32BE();
+	fileType = stream.readUint32BE();
 
 	// Check for TGZ files
 	if (fileType == MKTAG('T', 'G', 'Z', '\0')) {
 		// TGZ files have a header and then Bitmap data that is compressed with LZSS
-		uint32 decompressedSize = file.readSint32LE();
-		uint32 imageWidth = file.readSint32LE();
-		uint32 imageHeight = file.readSint32LE();
+		uint32 decompressedSize = stream.readSint32LE();
+		uint32 imageWidth = stream.readSint32LE();
+		uint32 imageHeight = stream.readSint32LE();
 
-		LzssReadStream stream(&file);
+		LzssReadStream stream(&stream);
 		byte *buffer = new byte[decompressedSize];
 		stream.read(buffer, decompressedSize);
 
@@ -129,11 +133,11 @@ void RenderManager::renderImageToScreen(const Common::String &fileName, uint32 d
 		delete[] buffer;
 	} else {
 		// Reset the cursor
-		file.seek(0);
+		stream.seek(0);
 
 		// Decode
 		Graphics::TGADecoder tga;
-		if (!tga.loadStream(file)) {
+		if (!tga.loadStream(stream)) {
 			warning("Error while reading TGA image");
 			return;
 		}
diff --git a/engines/zvision/render_manager.h b/engines/zvision/render_manager.h
index 8b4d7e840b..f9d1375ecf 100644
--- a/engines/zvision/render_manager.h
+++ b/engines/zvision/render_manager.h
@@ -34,6 +34,7 @@ class OSystem;
 
 namespace Common {
 class String;
+class SeekableReadStream;
 }
 
 namespace Video {
@@ -89,6 +90,17 @@ public:
 	 */
 	void renderImageToScreen(const Common::String &fileName, uint32 destinationX, uint32 destinationY, Common::Rect subRectangle = Common::Rect(0, 0, 0, 0));
 
+	/**
+	 * Blits the image or a portion of the image to the screen. Actual screen updates won't happen until the end of the frame.
+	 * The image will be clipped to fit inside the window.
+	 *
+	 * @param stream          Stream to read the image data from
+	 * @param destinationX    X position where the image should be put
+	 * @param destinationY    Y position where the image should be put
+	 * @param subRectangle    The subrectangle of the image that should be rendered. If this is an empty rectangle, it will blit the entire image.
+	 */
+	void renderImageToScreen(Common::SeekableReadStream &stream, uint32 destinationX, uint32 destinationY, Common::Rect subRectangle = Common::Rect(0, 0, 0, 0));
+
 	RenderTable *getRenderTable();
 
 	bool needsScreenUpdate() { return _needsScreenUpdate; };