Image: extend writePng for 4-byte pixelFormat

1 files changed, 38 insertions, 9 deletions

diff --git a/image/png.cpp b/image/png.cpp
index e11f0459d2..fc0daf99b5 100644
--- a/image/png.cpp
+++ b/image/png.cpp
@@ -249,13 +249,35 @@ bool PNGDecoder::loadStream(Common::SeekableReadStream &stream) {
 
 bool writePNG(Common::WriteStream &out, const Graphics::Surface &input, const bool bottomUp) {
 #ifdef USE_PNG
-	const Graphics::PixelFormat requiredFormat(3, 8, 8, 8, 0, 16, 8, 0, 0);
+	const Graphics::PixelFormat requiredFormat_3byte(3, 8, 8, 8, 0, 16, 8, 0, 0);
+	const Graphics::PixelFormat requiredFormat_4byte(4, 8, 8, 8, 8, 16, 8, 0, 24);
 
-	if (input.format != requiredFormat) {
-		warning("Cannot currently write PNG with pixel format other than %s", requiredFormat.toString().c_str());
+	if (input.format.bytesPerPixel == 3) {
+		if (input.format != requiredFormat_3byte) {
+			warning("Cannot currently write PNG with 3-byte pixel format other than %s", requiredFormat_3byte.toString().c_str());
+			return false;
+		}
+	} else if (input.format.bytesPerPixel != 4) {
+		warning("Cannot currently write PNG with pixel format of bpp other than 3, 4");
 		return false;
 	}
 
+	int colorType;
+	Graphics::Surface *tmp = NULL;
+	const Graphics::Surface *surface;
+
+	if (input.format == requiredFormat_3byte) {
+		surface = &input;
+		colorType = PNG_COLOR_TYPE_RGB;
+	} else {
+		if (input.format == requiredFormat_4byte) {
+			surface = &input;
+		} else {
+			surface = tmp = input.convertTo(requiredFormat_4byte);
+		}
+		colorType = PNG_COLOR_TYPE_RGB_ALPHA;
+	}
+
 	png_structp pngPtr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 	if (!pngPtr) {
 		return false;
@@ -276,23 +298,30 @@ bool writePNG(Common::WriteStream &out, const Graphics::Surface &input, const bo
 
 	png_set_write_fn(pngPtr, &out, pngWriteToStream, pngFlushStream);
 
-	png_set_IHDR(pngPtr, infoPtr, input.w, input.h, 8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+	png_set_IHDR(pngPtr, infoPtr, surface->w, surface->h, 8, colorType, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
 
 	Common::Array<const uint8 *> rows;
-	rows.reserve(input.h);
+	rows.reserve(surface->h);
 	if (bottomUp) {
-		for (uint y = input.h; y-- > 0;) {
-			rows.push_back((const uint8 *)input.getBasePtr(0, y));
+		for (uint y = surface->h; y-- > 0;) {
+			rows.push_back((const uint8 *)surface->getBasePtr(0, y));
 		}
 	} else {
-		for (uint y = 0; y < input.h; ++y) {
-			rows.push_back((const uint8 *)input.getBasePtr(0, y));
+		for (uint y = 0; y < surface->h; ++y) {
+			rows.push_back((const uint8 *)surface->getBasePtr(0, y));
 		}
 	}
 
 	png_set_rows(pngPtr, infoPtr, const_cast<uint8 **>(&rows.front()));
 	png_write_png(pngPtr, infoPtr, 0, NULL);
 	png_destroy_write_struct(&pngPtr, &infoPtr);
+
+	// free tmp surface
+	if (tmp) {
+		tmp->free();
+		delete tmp;
+	}
+
 	return true;
 #else
 	return false;