Move Texture:generateMipmaps error handling out of backend code

src/modules/graphics/Texture.cpp

@@ -487,6 +487,17 @@ void Texture::replacePixels(const void *data, size_t size, int slice, int mipmap
 		generateMipmaps();
 }
 
+void Texture::generateMipmaps()
+{
+	if (getMipmapCount() == 1 || getMipmapsMode() == MIPMAPS_NONE)
+		throw love::Exception("generateMipmaps can only be called on a Texture which was created with mipmaps enabled.");
+
+	if (isPixelFormatCompressed(format))
+		throw love::Exception("generateMipmaps cannot be called on a compressed Texture.");
+
+	generateMipmapsInternal();
+}
+
 love::image::ImageData *Texture::newImageData(love::image::Image *module, int slice, int mipmap, const Rect &r)
 {
 	if (!isReadable())
@@ -521,7 +532,11 @@ love::image::ImageData *Texture::newImageData(love::image::Image *module, int sl
 		throw love::Exception("ImageData with the '%s' pixel format is not supported.", formatname);
 	}
 
-	return module->newImageData(r.w, r.h, dataformat);
+	auto imagedata = module->newImageData(r.w, r.h, dataformat);
+
+	readbackImageData(imagedata, slice, mipmap, r);
+
+	return imagedata;
 }
 
 TextureType Texture::getTextureType() const

src/modules/graphics/Texture.h

@@ -218,9 +218,9 @@ public:
 	void replacePixels(love::image::ImageDataBase *d, int slice, int mipmap, int x, int y, bool reloadmipmaps);
 	void replacePixels(const void *data, size_t size, int slice, int mipmap, const Rect &rect, bool reloadmipmaps);
 
-	virtual void generateMipmaps() = 0;
+	void generateMipmaps();
 
-	virtual love::image::ImageData *newImageData(love::image::Image *module, int slice, int mipmap, const Rect &rect);
+	love::image::ImageData *newImageData(love::image::Image *module, int slice, int mipmap, const Rect &rect);
 
 	virtual ptrdiff_t getRenderTargetHandle() const = 0;
 
@@ -278,6 +278,9 @@ protected:
 	void uploadImageData(love::image::ImageDataBase *d, int level, int slice, int x, int y);
 	virtual void uploadByteData(PixelFormat pixelformat, const void *data, size_t size, int level, int slice, const Rect &r, love::image::ImageDataBase *imgd = nullptr) = 0;
 
+	virtual void generateMipmapsInternal() = 0;
+	virtual void readbackImageData(love::image::ImageData *imagedata, int slice, int mipmap, const Rect &rect) = 0;
+
 	bool validateDimensions(bool throwException) const;
 
 	TextureType texType;

src/modules/graphics/opengl/Texture.cpp

@@ -480,14 +480,8 @@ void Texture::uploadByteData(PixelFormat pixelformat, const void *data, size_t s
 	}
 }
 
-void Texture::generateMipmaps()
+void Texture::generateMipmapsInternal()
 {
-	if (getMipmapCount() == 1 || getMipmapsMode() == MIPMAPS_NONE)
-		throw love::Exception("generateMipmaps can only be called on a Texture which was created with mipmaps enabled.");
-
-	if (isPixelFormatCompressed(format))
-		throw love::Exception("generateMipmaps cannot be called on a compressed Texture.");
-
 	gl.bindTextureToUnit(this, 0, false);
 
 	GLenum gltextype = OpenGL::getGLTextureType(texType);
@@ -498,13 +492,10 @@ void Texture::generateMipmaps()
 	glGenerateMipmap(gltextype);
 }
 
-love::image::ImageData *Texture::newImageData(love::image::Image *module, int slice, int mipmap, const Rect &r)
+void Texture::readbackImageData(love::image::ImageData *data, int slice, int mipmap, const Rect &r)
 {
-	// Base class does validation (only RTs allowed, etc) and creates ImageData.
-	love::image::ImageData *data = love::graphics::Texture::newImageData(module, slice, mipmap, r);
-
 	if (fbo == 0) // Should never be reached.
-		return data;
+		return;
 
 	bool isSRGB = false;
 	OpenGL::TextureFormat fmt = gl.convertPixelFormat(data->getFormat(), false, isSRGB);
@@ -525,8 +516,6 @@ love::image::ImageData *Texture::newImageData(love::image::Image *module, int sl
 		gl.framebufferTexture(GL_COLOR_ATTACHMENT0, texType, texture, 0, 0, 0);
 
 	gl.bindFramebuffer(OpenGL::FRAMEBUFFER_ALL, current_fbo);
-
-	return data;
 }
 
 void Texture::setSamplerState(const SamplerState &s)

src/modules/graphics/opengl/Texture.h

@@ -46,8 +46,6 @@ public:
 	bool loadVolatile() override;
 	void unloadVolatile() override;
 
-	void generateMipmaps() override;
-	love::image::ImageData *newImageData(love::image::Image *module, int slice, int mipmap, const Rect &rect) override;
 	void setSamplerState(const SamplerState &s) override;
 
 	ptrdiff_t getHandle() const override;
@@ -62,6 +60,10 @@ private:
 
 	void uploadByteData(PixelFormat pixelformat, const void *data, size_t size, int level, int slice, const Rect &r, love::image::ImageDataBase *imgd = nullptr) override;
 
+	void generateMipmapsInternal() override;
+
+	void readbackImageData(love::image::ImageData *imagedata, int slice, int mipmap, const Rect &rect) override;
+
 	Slices slices;
 
 	GLuint fbo;