Merge branch '12.0-development' into metal

src/modules/data/ByteData.cpp

@@ -42,7 +42,8 @@ ByteData::ByteData(const void *d, size_t size)
 	: size(size)
 {
 	create();
-	memcpy(data, d, size);
+	if (d != nullptr)
+		memcpy(data, d, size);
 }
 
 ByteData::ByteData(void *d, size_t size, bool own)
@@ -53,7 +54,8 @@ ByteData::ByteData(void *d, size_t size, bool own)
 	else
 	{
 		create();
-		memcpy(data, d, size);
+		if (d != nullptr)
+			memcpy(data, d, size);
 	}
 }
 

src/modules/graphics/Buffer.cpp

@@ -46,14 +46,10 @@ Buffer::Buffer(Graphics *gfx, const Settings &settings, const std::vector<DataDe
 	const auto &caps = gfx->getCapabilities();
 	bool supportsGLSL3 = caps.features[Graphics::FEATURE_GLSL3];
 
-	bool indexbuffer = settings.usageFlags & BUFFERUSAGEFLAG_INDEX;
-	bool vertexbuffer = settings.usageFlags & BUFFERUSAGEFLAG_VERTEX;
-	bool texelbuffer = settings.usageFlags & BUFFERUSAGEFLAG_TEXEL;
-	bool storagebuffer = settings.usageFlags & BUFFERUSAGEFLAG_SHADER_STORAGE;
-	bool copydest = settings.usageFlags & BUFFERUSAGEFLAG_COPY_DEST;
-
-	if (!indexbuffer && !vertexbuffer && !texelbuffer && !storagebuffer)
-		throw love::Exception("Buffer must be created with at least one buffer type (index, vertex, texel, or shaderstorage).");
+	bool indexbuffer = usageFlags & BUFFERUSAGEFLAG_INDEX;
+	bool vertexbuffer = usageFlags & BUFFERUSAGEFLAG_VERTEX;
+	bool texelbuffer = usageFlags & BUFFERUSAGEFLAG_TEXEL;
+	bool storagebuffer = usageFlags & BUFFERUSAGEFLAG_SHADER_STORAGE;
 
 	if (texelbuffer && !caps.features[Graphics::FEATURE_TEXEL_BUFFER])
 		throw love::Exception("Texel buffers are not supported on this system.");
@@ -61,8 +57,11 @@ Buffer::Buffer(Graphics *gfx, const Settings &settings, const std::vector<DataDe
 	if (storagebuffer && !caps.features[Graphics::FEATURE_GLSL4])
 		throw love::Exception("Shader Storage buffers are not supported on this system (GLSL 4 support is necessary.)");
 
-	if (copydest && dataUsage == BUFFERDATAUSAGE_STREAM)
-		throw love::Exception("Buffers created with 'stream' data usage cannot be used as a copy destination.");
+	if (storagebuffer && dataUsage == BUFFERDATAUSAGE_STREAM)
+		throw love::Exception("Buffers created with 'stream' data usage cannot be used as a shader storage buffer.");
+
+	if (dataUsage == BUFFERDATAUSAGE_STAGING && (indexbuffer || vertexbuffer || texelbuffer || storagebuffer))
+		throw love::Exception("Buffers created with 'staging' data usage cannot be index, vertex, texel, or shaderstorage buffer types.");
 
 	size_t offset = 0;
 	size_t stride = 0;

src/modules/graphics/Graphics.cpp

@@ -1104,15 +1104,12 @@ void Graphics::copyBuffer(Buffer *source, Buffer *dest, size_t sourceoffset, siz
 	if (!capabilities.features[FEATURE_COPY_BUFFER])
 		throw love::Exception("Buffer copying is not supported on this system.");
 
-	if (!(source->getUsageFlags() & BUFFERUSAGEFLAG_COPY_SOURCE))
-		throw love::Exception("Copy source buffer must be created with the copysource flag.");
-
-	if (!(dest->getUsageFlags() & BUFFERUSAGEFLAG_COPY_DEST))
-		throw love::Exception("Copy destination buffer must be created with the copydest flag.");
-
 	Range sourcerange(sourceoffset, size);
 	Range destrange(destoffset, size);
 
+	if (dest->getDataUsage() == BUFFERDATAUSAGE_STREAM)
+		throw love::Exception("Buffers created with 'stream' data usage cannot be used as a copy destination.");
+
 	if (sourcerange.getMax() >= source->getSize())
 		throw love::Exception("Buffer copy source offset and size doesn't fit within the source Buffer's size.");
 
@@ -1125,6 +1122,169 @@ void Graphics::copyBuffer(Buffer *source, Buffer *dest, size_t sourceoffset, siz
 	source->copyTo(dest, sourceoffset, destoffset, size);
 }
 
+void Graphics::copyTextureToBuffer(Texture *source, Buffer *dest, int slice, int mipmap, const Rect &rect, size_t destoffset, int destwidth)
+{
+	if (!capabilities.features[FEATURE_COPY_TEXTURE_TO_BUFFER])
+	{
+		if (!source->isRenderTarget())
+			throw love::Exception("Copying a non-render target Texture to a Buffer is not supported on this system.");
+
+		if (!capabilities.features[FEATURE_COPY_RENDER_TARGET_TO_BUFFER])
+			throw love::Exception("Copying a render target Texture to a Buffer is not supported on this system.");
+	}
+
+	PixelFormat format = source->getPixelFormat();
+
+	if (isPixelFormatDepthStencil(format))
+		throw love::Exception("Copying a depth/stencil Texture to a Buffer is not supported.");
+
+	if (!source->isReadable())
+		throw love::Exception("copyTextureToBuffer can only be called on readable Textures.");
+
+	if (dest->getDataUsage() == BUFFERDATAUSAGE_STREAM)
+		throw love::Exception("Buffers created with 'stream' data usage cannot be used as a copy destination.");
+
+	if (isRenderTargetActive(source))
+		throw love::Exception("copyTextureToBuffer cannot be called while the Texture is an active render target.");
+
+	if (mipmap < 0 || mipmap >= source->getMipmapCount())
+		throw love::Exception("Invalid texture mipmap index %d.", mipmap + 1);
+
+	TextureType textype = source->getTextureType();
+	if (slice < 0 || (textype == TEXTURE_CUBE && slice >= 6)
+		|| (textype == TEXTURE_VOLUME && slice >= source->getDepth(mipmap))
+		|| (textype == TEXTURE_2D_ARRAY && slice >= source->getLayerCount()))
+	{
+		throw love::Exception("Invalid texture slice index %d.", slice + 1);
+	}
+
+	int mipw = source->getPixelWidth(mipmap);
+	int miph = source->getPixelHeight(mipmap);
+
+	if (rect.x < 0 || rect.y < 0 || rect.w <= 0 || rect.h <= 0
+		|| (rect.x + rect.w) > mipw || (rect.y + rect.h) > miph)
+	{
+		throw love::Exception("Invalid rectangle dimensions (x=%d, y=%d, w=%d, h=%d) for %dx%d texture.", rect.x, rect.y, rect.w, rect.h, mipw, miph);
+	}
+
+	if (destwidth <= 0)
+		destwidth = rect.w;
+
+	size_t size = 0;
+
+	if (isPixelFormatCompressed(format))
+	{
+		if (destwidth != rect.w) // OpenGL limitation...
+			throw love::Exception("Copying a compressed texture to a buffer cannot use a custom destination width.");
+
+		const PixelFormatInfo &info = getPixelFormatInfo(format);
+		int bw = (int) info.blockWidth;
+		int bh = (int) info.blockHeight;
+		if (rect.x % bw != 0 || rect.y % bh != 0 ||
+			((rect.w % bw != 0 || rect.h % bh != 0) && rect.x + rect.w != source->getPixelWidth(mipmap)))
+		{
+			const char *name = nullptr;
+			love::getConstant(format, name);
+			throw love::Exception("Compressed texture format %s only supports copying a sub-rectangle with offset and dimensions that are a multiple of %d x %d.", name, bw, bh);
+		}
+
+		// Note: this will need to change if destwidth == rect.w restriction
+		// is removed.
+		size = getPixelFormatSliceSize(format, destwidth, rect.h);
+	}
+	else
+	{
+		// Not the cleanest, but should work since uncompressed formats always
+		// have 1x1 blocks.
+		int pixels = (rect.h - 1) * destwidth + rect.w;
+		size = getPixelFormatUncompressedRowSize(format, pixels);
+	}
+
+	Range destrange(destoffset, size);
+
+	if (destrange.getMax() >= dest->getSize())
+		throw love::Exception("Buffer copy destination offset and width/height doesn't fit within the destination Buffer.");
+
+	source->copyToBuffer(dest, slice, mipmap, rect, destoffset, destwidth, size);
+}
+
+void Graphics::copyBufferToTexture(Buffer *source, Texture *dest, size_t sourceoffset, int sourcewidth, int slice, int mipmap, const Rect &rect)
+{
+	if (!capabilities.features[FEATURE_COPY_BUFFER_TO_TEXTURE])
+		throw love::Exception("Copying a Buffer to a Texture is not supported on this system.");
+
+	PixelFormat format = dest->getPixelFormat();
+
+	if (isPixelFormatDepthStencil(format))
+		throw love::Exception("Copying a Buffer to a depth/stencil Texture is not supported.");
+
+	if (!dest->isReadable())
+		throw love::Exception("copyBufferToTexture can only be called on readable Textures.");
+
+	if (isRenderTargetActive(dest))
+		throw love::Exception("copyBufferToTexture cannot be called while the Texture is an active render target.");
+
+	if (mipmap < 0 || mipmap >= dest->getMipmapCount())
+		throw love::Exception("Invalid texture mipmap index %d.", mipmap + 1);
+
+	TextureType textype = dest->getTextureType();
+	if (slice < 0 || (textype == TEXTURE_CUBE && slice >= 6)
+		|| (textype == TEXTURE_VOLUME && slice >= dest->getDepth(mipmap))
+		|| (textype == TEXTURE_2D_ARRAY && slice >= dest->getLayerCount()))
+	{
+		throw love::Exception("Invalid texture slice index %d.", slice + 1);
+	}
+
+	int mipw = dest->getPixelWidth(mipmap);
+	int miph = dest->getPixelHeight(mipmap);
+
+	if (rect.x < 0 || rect.y < 0 || rect.w <= 0 || rect.h <= 0
+		|| (rect.x + rect.w) > mipw || (rect.y + rect.h) > miph)
+	{
+		throw love::Exception("Invalid rectangle dimensions (x=%d, y=%d, w=%d, h=%d) for %dx%d texture.", rect.x, rect.y, rect.w, rect.h, mipw, miph);
+	}
+
+	if (sourcewidth <= 0)
+		sourcewidth = rect.w;
+
+	size_t size = 0;
+
+	if (isPixelFormatCompressed(format))
+	{
+		if (sourcewidth != rect.w) // OpenGL limitation...
+			throw love::Exception("Copying a buffer to a compressed texture cannot use a custom source width.");
+
+		const PixelFormatInfo &info = getPixelFormatInfo(format);
+		int bw = (int) info.blockWidth;
+		int bh = (int) info.blockHeight;
+		if (rect.x % bw != 0 || rect.y % bh != 0 ||
+			((rect.w % bw != 0 || rect.h % bh != 0) && rect.x + rect.w != dest->getPixelWidth(mipmap)))
+		{
+			const char *name = nullptr;
+			love::getConstant(format, name);
+			throw love::Exception("Compressed texture format %s only supports copying a sub-rectangle with offset and dimensions that are a multiple of %d x %d.", name, bw, bh);
+		}
+
+		// Note: this will need to change if sourcewidth == rect.w restriction
+		// is removed.
+		size = getPixelFormatSliceSize(format, sourcewidth, rect.h);
+	}
+	else
+	{
+		// Not the cleanest, but should work since uncompressed formats always
+		// have 1x1 blocks.
+		int pixels = (rect.h - 1) * sourcewidth + rect.w;
+		size = getPixelFormatUncompressedRowSize(format, pixels);
+	}
+
+	Range sourcerange(sourceoffset, size);
+
+	if (sourcerange.getMax() >= source->getSize())
+		throw love::Exception("Buffer copy source offset and width/height doesn't fit within the source Buffer.");
+
+	dest->copyFromBuffer(source, sourceoffset, sourcewidth, size, slice, mipmap, rect);
+}
+
 void Graphics::dispatchThreadgroups(Shader* shader, int x, int y, int z)
 {
 	if (!shader->hasStage(SHADERSTAGE_COMPUTE))
@@ -1956,6 +2116,9 @@ STRINGMAP_CLASS_BEGIN(Graphics, Graphics::Feature, Graphics::FEATURE_MAX_ENUM, f
 	{ "instancing",               Graphics::FEATURE_INSTANCING           },
 	{ "texelbuffer",              Graphics::FEATURE_TEXEL_BUFFER         },
 	{ "copybuffer",               Graphics::FEATURE_COPY_BUFFER          },
+	{ "copybuffertotexture",      Graphics::FEATURE_COPY_BUFFER_TO_TEXTURE },
+	{ "copytexturetobuffer",      Graphics::FEATURE_COPY_TEXTURE_TO_BUFFER },
+	{ "copyrendertargettobuffer", Graphics::FEATURE_COPY_RENDER_TARGET_TO_BUFFER },
 }
 STRINGMAP_CLASS_END(Graphics, Graphics::Feature, Graphics::FEATURE_MAX_ENUM, feature)
 

src/modules/graphics/Graphics.h

@@ -145,6 +145,9 @@ public:
 		FEATURE_INSTANCING,
 		FEATURE_TEXEL_BUFFER,
 		FEATURE_COPY_BUFFER,
+		FEATURE_COPY_BUFFER_TO_TEXTURE,
+		FEATURE_COPY_TEXTURE_TO_BUFFER,
+		FEATURE_COPY_RENDER_TARGET_TO_BUFFER,
 		FEATURE_MAX_ENUM
 	};
 
@@ -675,6 +678,8 @@ public:
 	void captureScreenshot(const ScreenshotInfo &info);
 
 	void copyBuffer(Buffer *source, Buffer *dest, size_t sourceoffset, size_t destoffset, size_t size);
+	void copyTextureToBuffer(Texture *source, Buffer *dest, int slice, int mipmap, const Rect &rect, size_t destoffset, int destwidth);
+	void copyBufferToTexture(Buffer *source, Texture *dest, size_t sourceoffset, int sourcewidth, int slice, int mipmap, const Rect &rect);
 
 	void dispatchThreadgroups(Shader* shader, int x, int y, int z);
 

src/modules/graphics/Texture.cpp

@@ -473,9 +473,18 @@ void Texture::replacePixels(love::image::ImageDataBase *d, int slice, int mipmap
 		throw love::Exception("Invalid rectangle dimensions (x=%d, y=%d, w=%d, h=%d) for %dx%d Texture.", rect.x, rect.y, rect.w, rect.h, mipw, miph);
 	}
 
-	// We don't currently support partial updates of compressed textures.
 	if (isPixelFormatCompressed(d->getFormat()) && (rect.x != 0 || rect.y != 0 || rect.w != mipw || rect.h != miph))
-		throw love::Exception("Compressed textures only support replacing the entire Texture.");
+	{
+		const PixelFormatInfo &info = getPixelFormatInfo(d->getFormat());
+		int bw = (int) info.blockWidth;
+		int bh = (int) info.blockHeight;
+		if (rect.x % bw != 0 || rect.y % bh != 0 || rect.w % bw != 0 || rect.h % bh != 0)
+		{
+			const char *name = nullptr;
+			love::getConstant(d->getFormat(), name);
+			throw love::Exception("Compressed texture format %s only supports replacing a sub-rectangle with offset and dimensions that are a multiple of %d x %d.", name, bw, bh);
+		}
+	}
 
 	Graphics::flushBatchedDrawsGlobal();
 

src/modules/graphics/Texture.h

@@ -46,6 +46,7 @@ namespace graphics
 {
 
 class Graphics;
+class Buffer;
 
 enum TextureType
 {
@@ -246,6 +247,9 @@ public:
 
 	love::image::ImageData *newImageData(love::image::Image *module, int slice, int mipmap, const Rect &rect);
 
+	virtual void copyFromBuffer(Buffer *source, size_t sourceoffset, int sourcewidth, size_t size, int slice, int mipmap, const Rect &rect) = 0;
+	virtual void copyToBuffer(Buffer *dest, int slice, int mipmap, const Rect &rect, size_t destoffset, int destwidth, size_t size) = 0;
+
 	virtual ptrdiff_t getRenderTargetHandle() const = 0;
 	virtual ptrdiff_t getSamplerHandle() const = 0;
 

src/modules/graphics/metal/Graphics.mm

@@ -2100,7 +2100,10 @@ void Graphics::initCapabilities()
 	capabilities.features[FEATURE_INSTANCING] = true;
 	capabilities.features[FEATURE_TEXEL_BUFFER] = true;
 	capabilities.features[FEATURE_COPY_BUFFER] = true;
-	static_assert(FEATURE_MAX_ENUM == 12, "Graphics::initCapabilities must be updated when adding a new graphics feature!");
+	capabilities.features[FEATURE_COPY_BUFFER_TO_TEXTURE] = true;
+	capabilities.features[FEATURE_COPY_TEXTURE_TO_BUFFER] = true;
+	capabilities.features[FEATURE_COPY_RENDER_TARGET_TO_BUFFER] = true;
+	static_assert(FEATURE_MAX_ENUM == 15, "Graphics::initCapabilities must be updated when adding a new graphics feature!");
 
 	// https://developer.apple.com/metal/Metal-Feature-Set-Tables.pdf
 	capabilities.limits[LIMIT_POINT_SIZE] = 511;

src/modules/graphics/metal/Texture.h

@@ -40,6 +40,9 @@ public:
 	Texture(love::graphics::Graphics *gfx, id<MTLDevice> device, const Settings &settings, const Slices *data);
 	virtual ~Texture();
 
+	void copyFromBuffer(love::graphics::Buffer *source, size_t sourceoffset, int sourcewidth, size_t size, int slice, int mipmap, const Rect &rect) override;
+	void copyToBuffer(love::graphics::Buffer *dest, int slice, int mipmap, const Rect &rect, size_t destoffset, int destwidth, size_t size) override;
+
 	void setSamplerState(const SamplerState &s) override;
 
 	ptrdiff_t getHandle() const override { return (ptrdiff_t) texture; }

src/modules/graphics/metal/Texture.mm

@@ -258,6 +258,16 @@ void Texture::readbackImageData(love::image::ImageData *imagedata, int slice, in
 	memcpy(imagedata->getData(), buffer.contents, imagedata->getSize());
 }}
 
+void Texture::copyFromBuffer(love::graphics::Buffer *source, size_t sourceoffset, int sourcewidth, size_t size, int slice, int mipmap, const Rect &rect)
+{
+	// TODO
+}
+
+void Texture::copyToBuffer(love::graphics::Buffer *dest, int slice, int mipmap, const Rect &rect, size_t destoffset, int destwidth, size_t size)
+{
+	// TODO
+}
+
 void Texture::setSamplerState(const SamplerState &s)
 { @autoreleasepool {
 	// Base class does common validation and assigns samplerState.

src/modules/graphics/opengl/Buffer.cpp

@@ -80,10 +80,6 @@ Buffer::Buffer(love::graphics::Graphics *gfx, const Settings &settings, const st
 		mapUsage = BUFFERUSAGE_INDEX;
 	else  if (usageFlags & BUFFERUSAGEFLAG_SHADER_STORAGE)
 		mapUsage = BUFFERUSAGE_SHADER_STORAGE;
-	else if (usageFlags & BUFFERUSAGEFLAG_COPY_SOURCE)
-		mapUsage = BUFFERUSAGE_COPY_SOURCE;
-	else if (usageFlags & BUFFERUSAGEFLAG_COPY_DEST)
-		mapUsage = BUFFERUSAGE_COPY_DEST;
 
 	target = OpenGL::getGLBufferType(mapUsage);
 
@@ -161,6 +157,11 @@ bool Buffer::load(const void *initialdata)
 	return (glGetError() == GL_NO_ERROR);
 }
 
+bool Buffer::supportsOrphan() const
+{
+	return dataUsage == BUFFERDATAUSAGE_STREAM || dataUsage == BUFFERDATAUSAGE_DYNAMIC;
+}
+
 void *Buffer::map(MapType /*map*/, size_t offset, size_t size)
 {
 	if (size == 0)
@@ -206,7 +207,7 @@ void Buffer::unmap(size_t usedoffset, size_t usedsize)
 	mapped = false;
 
 	// Orphan optimization - see fill().
-	if (dataUsage != BUFFERDATAUSAGE_STATIC && mappedRange.first == 0 && mappedRange.getSize() == getSize())
+	if (supportsOrphan() && mappedRange.first == 0 && mappedRange.getSize() == getSize())
 	{
 		usedoffset = 0;
 		usedsize = getSize();
@@ -238,15 +239,14 @@ void Buffer::fill(size_t offset, size_t size, const void *data)
 
 	gl.bindBuffer(mapUsage, buffer);
 
-	if (dataUsage != BUFFERDATAUSAGE_STATIC && size == buffersize)
+	if (supportsOrphan() && size == buffersize)
 	{
 		// "orphan" current buffer to avoid implicit synchronisation on the GPU:
 		// http://www.seas.upenn.edu/~pcozzi/OpenGLInsights/OpenGLInsights-AsynchronousBufferTransfers.pdf
-		gl.bindBuffer(mapUsage, buffer);
 		glBufferData(target, (GLsizeiptr) buffersize, nullptr, gldatausage);
 
 #if LOVE_WINDOWS
-		// TODO: Verify that this codepath is a useful optimization.
+		// TODO: Verify that this intel codepath is a useful optimization.
 		if (gl.getVendor() == OpenGL::VENDOR_INTEL)
 			glBufferData(target, (GLsizeiptr) buffersize, data, gldatausage);
 		else
@@ -261,8 +261,9 @@ void Buffer::fill(size_t offset, size_t size, const void *data)
 
 void Buffer::copyTo(love::graphics::Buffer *dest, size_t sourceoffset, size_t destoffset, size_t size)
 {
-	gl.bindBuffer(BUFFERUSAGE_COPY_SOURCE, buffer);
-	gl.bindBuffer(BUFFERUSAGE_COPY_DEST, ((Buffer *) dest)->buffer);
+	// TODO: tracked state for these bind types?
+	glBindBuffer(GL_COPY_READ_BUFFER, buffer);
+	glBindBuffer(GL_COPY_WRITE_BUFFER, ((Buffer *) dest)->buffer);
 
 	glCopyBufferSubData(GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER, sourceoffset, destoffset, size);
 }

src/modules/graphics/opengl/Buffer.h

@@ -61,9 +61,7 @@ public:
 private:
 
 	bool load(const void *initialdata);
-
-	void unmapStatic(size_t offset, size_t size);
-	void unmapStream();
+	bool supportsOrphan() const;
 
 	BufferUsage mapUsage = BUFFERUSAGE_VERTEX;
 	GLenum target = 0;

src/modules/graphics/opengl/Graphics.cpp

@@ -509,8 +509,7 @@ static bool computeDispatchBarriers(Shader *shader, GLbitfield &preDispatchBarri
 		if (usage & BUFFERUSAGEFLAG_VERTEX)
 			postDispatchBarriers |= GL_VERTEX_ATTRIB_ARRAY_BARRIER_BIT;
 
-		if (usage & (BUFFERUSAGEFLAG_COPY_SOURCE | BUFFERUSAGEFLAG_COPY_DEST))
-			postDispatchBarriers |= GL_PIXEL_BUFFER_BARRIER_BIT;
+		postDispatchBarriers |= GL_PIXEL_BUFFER_BARRIER_BIT;
 	}
 
 	for (const auto &binding : shader->getStorageTextureBindings())
@@ -858,7 +857,7 @@ void Graphics::clear(OptionalColorD c, OptionalInt stencil, OptionalDouble depth
 
 	if (c.hasValue)
 	{
-		Colorf cf((float)c.value.r, (float)c.value.g, (float)c.value.b, (float)c.value.b);
+		Colorf cf((float)c.value.r, (float)c.value.g, (float)c.value.b, (float)c.value.a);
 		gammaCorrectColor(cf);
 		glClearColor(cf.r, cf.g, cf.b, cf.a);
 		flags |= GL_COLOR_BUFFER_BIT;
@@ -1658,8 +1657,11 @@ void Graphics::initCapabilities()
 	capabilities.features[FEATURE_GLSL4] = GLAD_ES_VERSION_3_1 || (gl.isCoreProfile() && GLAD_VERSION_4_3);
 	capabilities.features[FEATURE_INSTANCING] = gl.isInstancingSupported();
 	capabilities.features[FEATURE_TEXEL_BUFFER] = gl.isBufferUsageSupported(BUFFERUSAGE_TEXEL);
-	capabilities.features[FEATURE_COPY_BUFFER] = gl.isBufferUsageSupported(BUFFERUSAGE_COPY_SOURCE);
-	static_assert(FEATURE_MAX_ENUM == 12, "Graphics::initCapabilities must be updated when adding a new graphics feature!");
+	capabilities.features[FEATURE_COPY_BUFFER] = gl.isCopyBufferSupported();
+	capabilities.features[FEATURE_COPY_BUFFER_TO_TEXTURE] = gl.isCopyBufferToTextureSupported();
+	capabilities.features[FEATURE_COPY_TEXTURE_TO_BUFFER] = gl.isCopyTextureToBufferSupported();
+	capabilities.features[FEATURE_COPY_RENDER_TARGET_TO_BUFFER] = gl.isCopyRenderTargetToBufferSupported();
+	static_assert(FEATURE_MAX_ENUM == 15, "Graphics::initCapabilities must be updated when adding a new graphics feature!");
 
 	capabilities.limits[LIMIT_POINT_SIZE] = gl.getMaxPointSize();
 	capabilities.limits[LIMIT_TEXTURE_SIZE] = gl.getMax2DTextureSize();

src/modules/graphics/opengl/OpenGL.cpp

@@ -666,8 +666,6 @@ GLenum OpenGL::getGLBufferType(BufferUsage usage)
 		case BUFFERUSAGE_INDEX: return GL_ELEMENT_ARRAY_BUFFER;
 		case BUFFERUSAGE_TEXEL: return GL_TEXTURE_BUFFER;
 		case BUFFERUSAGE_SHADER_STORAGE: return GL_SHADER_STORAGE_BUFFER;
-		case BUFFERUSAGE_COPY_SOURCE: return GL_COPY_READ_BUFFER;
-		case BUFFERUSAGE_COPY_DEST: return GL_COPY_WRITE_BUFFER;
 		case BUFFERUSAGE_MAX_ENUM: return GL_ZERO;
 	}
 
@@ -844,6 +842,8 @@ GLenum OpenGL::getGLBufferDataUsage(BufferDataUsage usage)
 		case BUFFERDATAUSAGE_STREAM: return GL_STREAM_DRAW;
 		case BUFFERDATAUSAGE_DYNAMIC: return GL_DYNAMIC_DRAW;
 		case BUFFERDATAUSAGE_STATIC: return GL_STATIC_DRAW;
+		case BUFFERDATAUSAGE_STAGING:
+			return (GLAD_VERSION_1_1 || GLAD_ES_VERSION_3_0) ? GL_STREAM_READ : GL_STREAM_DRAW;
 		default: return 0;
 	}
 }
@@ -1483,9 +1483,6 @@ bool OpenGL::isBufferUsageSupported(BufferUsage usage) const
 		return GLAD_VERSION_3_1;
 	case BUFFERUSAGE_SHADER_STORAGE:
 		return (GLAD_VERSION_4_3 && isCoreProfile()) || GLAD_ES_VERSION_3_1;
-	case BUFFERUSAGE_COPY_SOURCE:
-	case BUFFERUSAGE_COPY_DEST:
-		return GLAD_VERSION_3_1 || GLAD_ES_VERSION_3_0;
 	case BUFFERUSAGE_MAX_ENUM:
 		return false;
 	}
@@ -1530,6 +1527,29 @@ bool OpenGL::isMultiFormatMRTSupported() const
 	return getMaxRenderTargets() > 1 && (GLAD_ES_VERSION_3_0 || GLAD_VERSION_3_0 || GLAD_ARB_framebuffer_object);
 }
 
+bool OpenGL::isCopyBufferSupported() const
+{
+	return GLAD_VERSION_3_1 || GLAD_ES_VERSION_3_0;
+}
+
+bool OpenGL::isCopyBufferToTextureSupported() const
+{
+	// Requires pixel unpack buffer binding support.
+	return GLAD_VERSION_2_0 || GLAD_ES_VERSION_3_0;
+}
+
+bool OpenGL::isCopyTextureToBufferSupported() const
+{
+	// Requires glGetTextureSubImage support.
+	return GLAD_VERSION_4_5 || GLAD_ARB_get_texture_sub_image;
+}
+
+bool OpenGL::isCopyRenderTargetToBufferSupported() const
+{
+	// Requires pixel pack buffer binding support.
+	return GLAD_VERSION_2_0 || GLAD_ES_VERSION_3_0;
+}
+
 int OpenGL::getMax2DTextureSize() const
 {
 	return std::max(max2DTextureSize, 1);

src/modules/graphics/opengl/OpenGL.h

@@ -371,6 +371,10 @@ public:
 	bool isSamplerLODBiasSupported() const;
 	bool isBaseVertexSupported() const;
 	bool isMultiFormatMRTSupported() const;
+	bool isCopyBufferSupported() const;
+	bool isCopyBufferToTextureSupported() const;
+	bool isCopyTextureToBufferSupported() const;
+	bool isCopyRenderTargetToBufferSupported() const;
 
 	/**
 	 * Returns the maximum supported width or height of a texture.

src/modules/graphics/opengl/Texture.cpp

@@ -22,6 +22,7 @@
 
 #include "graphics/Graphics.h"
 #include "Graphics.h"
+#include "Buffer.h"
 #include "common/int.h"
 
 // STD
@@ -466,13 +467,16 @@ void Texture::uploadByteData(PixelFormat pixelformat, const void *data, size_t s
 
 	if (isPixelFormatCompressed(pixelformat))
 	{
-		if (r.x != 0 || r.y != 0)
-			throw love::Exception("x and y parameters must be 0 for compressed textures.");
-
 		if (texType == TEXTURE_2D || texType == TEXTURE_CUBE)
-			glCompressedTexImage2D(gltarget, level, fmt.internalformat, r.w, r.h, 0, size, data);
+		{
+			// Possible issues on some very old drivers if TexSubImage is used.
+			if (r.x != 0 || r.y != 0 || r.w != getPixelWidth(level) || r.h != getPixelHeight(level))
+				glCompressedTexSubImage2D(gltarget, level, r.x, r.y, r.w, r.h, fmt.internalformat, size, data);
+			else
+				glCompressedTexImage2D(gltarget, level, fmt.internalformat, r.w, r.h, 0, size, data);
+		}
 		else if (texType == TEXTURE_2D_ARRAY || texType == TEXTURE_VOLUME)
-			glCompressedTexSubImage3D(gltarget, level, 0, 0, slice, r.w, r.h, 1, fmt.internalformat, size, data);
+			glCompressedTexSubImage3D(gltarget, level, r.x, r.y, slice, r.w, r.h, 1, fmt.internalformat, size, data);
 	}
 	else
 	{
@@ -521,6 +525,75 @@ void Texture::readbackImageData(love::image::ImageData *data, int slice, int mip
 	gl.bindFramebuffer(OpenGL::FRAMEBUFFER_ALL, current_fbo);
 }
 
+void Texture::copyFromBuffer(love::graphics::Buffer *source, size_t sourceoffset, int sourcewidth, size_t size, int slice, int mipmap, const Rect &rect)
+{
+	// Higher level code does validation.
+
+	GLuint glbuffer = (GLuint) source->getHandle();
+	glBindBuffer(GL_PIXEL_UNPACK_BUFFER, glbuffer);
+
+	if (!isCompressed()) // Not supported in GL with compressed textures...
+		glPixelStorei(GL_UNPACK_ROW_LENGTH, sourcewidth);
+
+	// glTexSubImage and friends copy from the active pixel_unpack_buffer by
+	// treating the pointer as a byte offset.
+	const uint8 *byteoffset = (const uint8 *)(ptrdiff_t)sourceoffset;
+	uploadByteData(format, byteoffset, size, mipmap, slice, rect);
+
+	glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
+	glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+}
+
+void Texture::copyToBuffer(love::graphics::Buffer *dest, int slice, int mipmap, const Rect &rect, size_t destoffset, int destwidth, size_t size)
+{
+	// Higher level code does validation.
+
+	GLuint glbuffer = (GLuint) dest->getHandle();
+	glBindBuffer(GL_PIXEL_PACK_BUFFER, glbuffer);
+
+	if (!isCompressed()) // Not supported in GL with compressed textures...
+		glPixelStorei(GL_PACK_ROW_LENGTH, destwidth);
+
+	gl.bindTextureToUnit(this, 0, false);
+
+	bool isSRGB = false;
+	OpenGL::TextureFormat fmt = gl.convertPixelFormat(format, false, isSRGB);
+
+	// glTexSubImage and friends copy from the active pixel_unpack_buffer by
+	// treating the pointer as a byte offset.
+	uint8 *byteoffset = (uint8 *)(ptrdiff_t)destoffset;
+
+	if (gl.isCopyTextureToBufferSupported())
+	{
+		if (isCompressed())
+			glGetCompressedTextureSubImage(texture, mipmap, rect.x, rect.y, slice, rect.w, rect.h, 1, size, byteoffset);
+		else
+			glGetTextureSubImage(texture, mipmap, rect.x, rect.y, slice, rect.w, rect.h, 1, fmt.externalformat, fmt.type, size, byteoffset);
+	}
+	else if (fbo)
+	{
+		GLuint current_fbo = gl.getFramebuffer(OpenGL::FRAMEBUFFER_ALL);
+		gl.bindFramebuffer(OpenGL::FRAMEBUFFER_ALL, getFBO());
+
+		if (slice > 0 || mipmap > 0)
+		{
+			int layer = texType == TEXTURE_CUBE ? 0 : slice;
+			int face = texType == TEXTURE_CUBE ? slice : 0;
+			gl.framebufferTexture(GL_COLOR_ATTACHMENT0, texType, texture, mipmap, layer, face);
+		}
+
+		glReadPixels(rect.x, rect.y, rect.w, rect.h, fmt.externalformat, fmt.type, byteoffset);
+
+		if (slice > 0 || mipmap > 0)
+			gl.framebufferTexture(GL_COLOR_ATTACHMENT0, texType, texture, 0, 0, 0);
+
+		gl.bindFramebuffer(OpenGL::FRAMEBUFFER_ALL, current_fbo);
+	}
+
+	glPixelStorei(GL_PACK_ROW_LENGTH, 0);
+	glBindBuffer(GL_PIXEL_PACK_BUFFER, 0);
+}
+
 void Texture::setSamplerState(const SamplerState &s)
 {
 	if (s.depthSampleMode.hasValue && !gl.isDepthCompareSampleSupported())

src/modules/graphics/opengl/Texture.h

@@ -46,6 +46,9 @@ public:
 	bool loadVolatile() override;
 	void unloadVolatile() override;
 
+	void copyFromBuffer(love::graphics::Buffer *source, size_t sourceoffset, int sourcewidth, size_t size, int slice, int mipmap, const Rect &rect) override;
+	void copyToBuffer(love::graphics::Buffer *dest, int slice, int mipmap, const Rect &rect, size_t destoffset, int destwidth, size_t size) override;
+
 	void setSamplerState(const SamplerState &s) override;
 
 	ptrdiff_t getHandle() const override;

src/modules/graphics/vertex.cpp

@@ -371,8 +371,6 @@ STRINGMAP_BEGIN(BufferUsage, BUFFERUSAGE_MAX_ENUM, bufferUsageName)
 	{ "index",         BUFFERUSAGE_INDEX          },
 	{ "texel",         BUFFERUSAGE_TEXEL          },
 	{ "shaderstorage", BUFFERUSAGE_SHADER_STORAGE },
-	{ "copysource",    BUFFERUSAGE_COPY_SOURCE    },
-	{ "copydest",      BUFFERUSAGE_COPY_DEST      },
 }
 STRINGMAP_END(BufferUsage, BUFFERUSAGE_MAX_ENUM, bufferUsageName)
 
@@ -388,6 +386,7 @@ STRINGMAP_BEGIN(BufferDataUsage, BUFFERDATAUSAGE_MAX_ENUM, bufferDataUsage)
 	{ "stream",  BUFFERDATAUSAGE_STREAM  },
 	{ "dynamic", BUFFERDATAUSAGE_DYNAMIC },
 	{ "static",  BUFFERDATAUSAGE_STATIC  },
+	{ "staging", BUFFERDATAUSAGE_STAGING },
 }
 STRINGMAP_END(BufferDataUsage, BUFFERDATAUSAGE_MAX_ENUM, bufferDataUsage)
 

src/modules/graphics/vertex.h

@@ -60,8 +60,6 @@ enum BufferUsage
 	BUFFERUSAGE_INDEX,
 	BUFFERUSAGE_TEXEL,
 	BUFFERUSAGE_SHADER_STORAGE,
-	BUFFERUSAGE_COPY_SOURCE,
-	BUFFERUSAGE_COPY_DEST,
 	BUFFERUSAGE_MAX_ENUM
 };
 
@@ -72,8 +70,6 @@ enum BufferUsageFlags
 	BUFFERUSAGEFLAG_INDEX = 1 << BUFFERUSAGE_INDEX,
 	BUFFERUSAGEFLAG_TEXEL = 1 << BUFFERUSAGE_TEXEL,
 	BUFFERUSAGEFLAG_SHADER_STORAGE = 1 << BUFFERUSAGE_SHADER_STORAGE,
-	BUFFERUSAGEFLAG_COPY_SOURCE = 1 << BUFFERUSAGE_COPY_SOURCE,
-	BUFFERUSAGEFLAG_COPY_DEST = 1 << BUFFERUSAGE_COPY_DEST,
 };
 
 enum IndexDataType
@@ -114,6 +110,7 @@ enum BufferDataUsage
 	BUFFERDATAUSAGE_STREAM,
 	BUFFERDATAUSAGE_DYNAMIC,
 	BUFFERDATAUSAGE_STATIC,
+	BUFFERDATAUSAGE_STAGING,
 	BUFFERDATAUSAGE_MAX_ENUM
 };
 

src/modules/graphics/wrap_Graphics.cpp

@@ -3353,6 +3353,70 @@ int w_copyBuffer(lua_State *L)
 	return 0;
 }
 
+int w_copyBufferToTexture(lua_State *L)
+{
+	Buffer *source = luax_checkbuffer(L, 1);
+	Texture *dest = luax_checktexture(L, 2);
+
+	ptrdiff_t sourceoffset = luaL_optinteger(L, 3, 0);
+	if (sourceoffset < 0)
+		return luaL_error(L, "copyBufferToTexture source offset cannot be negative.");
+
+	int sourcewidth = (int) luaL_optinteger(L, 4, 0);
+
+	int slice = 0;
+	int mipmap = 0;
+
+	if (dest->getTextureType() != TEXTURE_2D)
+		slice = (int) luaL_checkinteger(L, 5) - 1;
+
+	mipmap = (int) luaL_optinteger(L, 6, 1) - 1;
+
+	Rect rect = {0, 0, dest->getPixelWidth(mipmap), dest->getPixelHeight(mipmap)};
+	if (!lua_isnoneornil(L, 7))
+	{
+		rect.x = (int) luaL_checkinteger(L, 7);
+		rect.y = (int) luaL_checkinteger(L, 8);
+		rect.w = (int) luaL_checkinteger(L, 9);
+		rect.h = (int) luaL_checkinteger(L, 10);
+	}
+
+	luax_catchexcept(L, [&](){ instance()->copyBufferToTexture(source, dest, sourceoffset, sourcewidth, slice, mipmap, rect); });
+	return 0;
+}
+
+int w_copyTextureToBuffer(lua_State *L)
+{
+	Texture *source = luax_checktexture(L, 1);
+	Buffer *dest = luax_checkbuffer(L, 2);
+
+	int slice = 0;
+	int mipmap = 0;
+
+	if (source->getTextureType() != TEXTURE_2D)
+		slice = (int) luaL_checkinteger(L, 3) - 1;
+
+	mipmap = (int) luaL_optinteger(L, 4, 1) - 1;
+
+	Rect rect = {0, 0, source->getPixelWidth(mipmap), source->getPixelHeight(mipmap)};
+	if (!lua_isnoneornil(L, 5))
+	{
+		rect.x = (int) luaL_checkinteger(L, 5);
+		rect.y = (int) luaL_checkinteger(L, 6);
+		rect.w = (int) luaL_checkinteger(L, 7);
+		rect.h = (int) luaL_checkinteger(L, 8);
+	}
+
+	ptrdiff_t destoffset = luaL_optinteger(L, 9, 0);
+	if (destoffset < 0)
+		return luaL_error(L, "copyTextureToBuffer dest offset cannot be negative.");
+
+	int destwidth = (int) luaL_optinteger(L, 10, 0);
+
+	luax_catchexcept(L, [&](){ instance()->copyTextureToBuffer(source, dest, slice, mipmap, rect, destoffset, destwidth); });
+	return 0;
+}
+
 int w_flushBatch(lua_State *)
 {
 	instance()->flushBatchedDraws();
@@ -3553,6 +3617,8 @@ static const luaL_Reg functions[] =
 	{ "dispatchThreadgroups", w_dispatchThreadgroups },
 
 	{ "copyBuffer", w_copyBuffer },
+	{ "copyBufferToTexture", w_copyBufferToTexture },
+	{ "copyTextureToBuffer", w_copyTextureToBuffer },
 
 	{ "isCreated", w_isCreated },
 	{ "isActive", w_isActive },

src/modules/graphics/wrap_Texture.cpp

@@ -390,13 +390,13 @@ int w_Texture_newImageData(lua_State *L)
 
 	int slice = 0;
 	int mipmap = 0;
-	Rect rect = {0, 0, t->getPixelWidth(), t->getPixelHeight()};
 
 	if (t->getTextureType() != TEXTURE_2D)
 		slice = (int) luaL_checkinteger(L, 2) - 1;
 
 	mipmap = (int) luaL_optinteger(L, 3, 1) - 1;
 
+	Rect rect = {0, 0, t->getPixelWidth(mipmap), t->getPixelHeight(mipmap)};
 	if (!lua_isnoneornil(L, 4))
 	{
 		rect.x = (int) luaL_checkinteger(L, 4);