From 917c43de100807f4397e36b66b1a748dbf44370e Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 7 Feb 2021 18:15:18 +0200
Subject: [PATCH] Make it possible to load an image into an externally
 allocated buffer

---
 source/graphics/bmploader.cpp           |  1 -
 source/graphics/devil/devilloader.cpp   |  1 -
 source/graphics/image.cpp               | 18 +++++++++++++-----
 source/graphics/image.h                 |  2 ++
 source/graphics/imageloader.cpp         |  2 ++
 source/graphics/jpeg/jpegloader.cpp     |  1 -
 source/graphics/png/pngloader.cpp       |  2 --
 source/graphics/quartz/quartzloader.cpp |  1 -
 8 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/source/graphics/bmploader.cpp b/source/graphics/bmploader.cpp
index d88e2aa..a339463 100644
--- a/source/graphics/bmploader.cpp
+++ b/source/graphics/bmploader.cpp
@@ -98,7 +98,6 @@ void BmpLoader::load_headers_(Image::Data &data)
 
 void BmpLoader::load_pixels_(Image::Data &data)
 {
-	data.pixels = new char[data.stride*data.height];
 	if(invert_row_order)
 	{
 		for(unsigned y=0; y<data.height; ++y)
diff --git a/source/graphics/devil/devilloader.cpp b/source/graphics/devil/devilloader.cpp
index a669308..d4c7bff 100644
--- a/source/graphics/devil/devilloader.cpp
+++ b/source/graphics/devil/devilloader.cpp
@@ -135,7 +135,6 @@ void DevilLoader::load_pixels_(Image::Data &data)
 	ilBindImage(id);
 
 	unsigned data_size = data.stride*data.height;
-	data.pixels = new char[data_size];
 	ILubyte *il_data = ilGetData();
 	copy(il_data, il_data+data_size, data.pixels);
 
diff --git a/source/graphics/image.cpp b/source/graphics/image.cpp
index fcfd222..2835d05 100644
--- a/source/graphics/image.cpp
+++ b/source/graphics/image.cpp
@@ -14,6 +14,7 @@ Image::Data::Data():
 	fmt(RGB),
 	width(0),
 	height(0),
+	owned_pixels(0),
 	pixels(0)
 { }
 
@@ -22,7 +23,8 @@ Image::Data::Data(const Data &other):
 	width(other.width),
 	height(other.height),
 	stride(other.stride),
-	pixels(other.pixels ? new char[stride*height] : 0)
+	owned_pixels(other.pixels ? new char[stride*height] : 0),
+	pixels(owned_pixels)
 {
 	if(pixels)
 		copy(other.pixels, other.pixels+stride*height, pixels);
@@ -30,8 +32,8 @@ Image::Data::Data(const Data &other):
 
 Image::Data &Image::Data::operator=(const Data &other)
 {
-	delete[] pixels;
-	pixels = 0;
+	delete[] owned_pixels;
+	pixels = owned_pixels = 0;
 
 	fmt = other.fmt;
 	width = other.width;
@@ -40,7 +42,7 @@ Image::Data &Image::Data::operator=(const Data &other)
 
 	if(other.pixels)
 	{
-		pixels = new char[stride*height];
+		pixels = owned_pixels = new char[stride*height];
 		copy(other.pixels, other.pixels+stride*height, pixels);
 	}
 
@@ -49,7 +51,7 @@ Image::Data &Image::Data::operator=(const Data &other)
 
 Image::Data::~Data()
 {
-	delete[] pixels;
+	delete[] owned_pixels;
 }
 
 
@@ -72,6 +74,12 @@ void Image::load(ImageLoader &loader)
 	loader.load(data);
 }
 
+void Image::load_into(ImageLoader &loader, void *buffer)
+{
+	data.pixels = reinterpret_cast<char *>(buffer);
+	load(loader);
+}
+
 void Image::load_headers(ImageLoader &loader)
 {
 	if(loader.get_state()==ImageLoader::INITIAL)
diff --git a/source/graphics/image.h b/source/graphics/image.h
index 7b5236e..51147ce 100644
--- a/source/graphics/image.h
+++ b/source/graphics/image.h
@@ -20,6 +20,7 @@ public:
 		unsigned width;
 		unsigned height;
 		unsigned stride;
+		char *owned_pixels;
 		char *pixels;
 
 		Data();
@@ -35,6 +36,7 @@ public:
 	void load_file(const std::string &);
 	void load_io(IO::Seekable &);
 	void load(ImageLoader &);
+	void load_into(ImageLoader &, void *);
 	void load_headers(ImageLoader &);
 
 	PixelFormat get_format() const { return data.fmt; }
diff --git a/source/graphics/imageloader.cpp b/source/graphics/imageloader.cpp
index fa6fcf8..52b0874 100644
--- a/source/graphics/imageloader.cpp
+++ b/source/graphics/imageloader.cpp
@@ -91,6 +91,8 @@ void ImageLoader::load(Image::Data &data)
 
 	if(state<HEADERS_LOADED)
 		load_headers_(data);
+	if(!data.pixels)
+		data.pixels = data.owned_pixels = new char[data.stride*data.height];
 	load_pixels_(data);
 	state = FINISHED;
 }
diff --git a/source/graphics/jpeg/jpegloader.cpp b/source/graphics/jpeg/jpegloader.cpp
index 4dd9440..45689cf 100644
--- a/source/graphics/jpeg/jpegloader.cpp
+++ b/source/graphics/jpeg/jpegloader.cpp
@@ -136,7 +136,6 @@ void JpegLoader::load_headers_(Image::Data &data)
 
 void JpegLoader::load_pixels_(Image::Data &data)
 {
-	data.pixels = new char[data.stride*data.height];
 	JSAMPROW rows[8];
 	while(priv->jpeg.output_scanline<data.height)
 	{
diff --git a/source/graphics/png/pngloader.cpp b/source/graphics/png/pngloader.cpp
index 190d3cf..1dfa773 100644
--- a/source/graphics/png/pngloader.cpp
+++ b/source/graphics/png/pngloader.cpp
@@ -98,8 +98,6 @@ void PngLoader::load_pixels_(Image::Data &data)
 		throw bad_image_data(priv->message);
 	}
 
-	data.pixels = new char[data.stride*data.height];
-
 	if(priv->interlace==PNG_INTERLACE_ADAM7)
 	{
 		// ADAM7 requires all rows to be loaded at once
diff --git a/source/graphics/quartz/quartzloader.cpp b/source/graphics/quartz/quartzloader.cpp
index e025b66..3799bcd 100644
--- a/source/graphics/quartz/quartzloader.cpp
+++ b/source/graphics/quartz/quartzloader.cpp
@@ -121,7 +121,6 @@ void QuartzLoader::load_(Image::Data &data)
 {
 	CGDataProviderRef dp = CGImageGetDataProvider(image);
 	CFDataRef image_data = CGDataProviderCopyData(dp);
-	data.pixels = new char[data.height*data.stride];
 	unsigned offset = (alpha==kCGImageAlphaNoneSkipFirst);
 	CFRange range = CFRangeMake(offset, CFDataGetLength(image_data)-offset);
 	CFDataGetBytes(image_data, range, reinterpret_cast<UInt8 *>(data.pixels));
-- 
2.43.0