Bitmap: Add #v_flip / #h_flip methods

binding-mri/bitmap-binding.cpp

@@ -445,6 +445,28 @@ RB_METHOD(bitmapWriteToPng)
 	return self;
 }
 
+RB_METHOD(bitmapVFlip)
+{
+	RB_UNUSED_PARAM;
+
+	Bitmap *b = getPrivateData<Bitmap>(self);
+
+	b->vFlip();
+
+	return Qnil;
+}
+
+RB_METHOD(bitmapHFlip)
+{
+	RB_UNUSED_PARAM;
+
+	Bitmap *b = getPrivateData<Bitmap>(self);
+
+	b->hFlip();
+
+	return Qnil;
+}
+
 
 void
 bitmapBindingInit()
@@ -479,6 +501,8 @@ bitmapBindingInit()
 	}
 
 	_rb_define_method(klass, "write_to_png", bitmapWriteToPng);
+	_rb_define_method(klass, "v_flip", bitmapVFlip);
+	_rb_define_method(klass, "h_flip", bitmapHFlip);
 
 	INIT_PROP_BIND(Bitmap, Font, "font");
 }

doc/extension_doc.md

@@ -14,6 +14,11 @@ returns: self
 
 Writes the contents of the bitmap to `filename`, in PNG format.
 
+## Bitmap.v_flip() / .h_flip()
+returns: nil  
+
+Flips the bitmap image vertically / horizontally.
+
 ## Input.scroll_v()
 returns: Integer  
 

src/bitmap.cpp

@@ -259,6 +259,34 @@ struct BitmapPrivate
 
 		glState.viewport.pop();
 	}
+
+	void flip(const IntRect &srcRect)
+	{
+		TEXFBO newTex = shState->texPool().request(gl.width, gl.height);
+
+		SimpleShader &shader = shState->shaders().simple;
+		shader.bind();
+		shader.setTexOffsetX(0);
+		bindTexture(shader);
+
+		Quad &quad = shState->gpQuad();
+		quad.setTexPosRect(srcRect, IntRect(0, 0, gl.width, gl.height));
+		quad.setColor(Vec4(1, 1, 1, 1));
+
+		glState.blend.pushSet(false);
+		pushSetViewport(shader);
+
+		FBO::bind(newTex.fbo);
+		blitQuad(quad);
+
+		popViewport();
+		glState.blend.pop();
+
+		shState->texPool().release(gl);
+		gl = newTex;
+
+		onModified();
+	}
 };
 
 struct BitmapOpenHandler : FileSystem::OpenHandler
@@ -1410,6 +1438,22 @@ void Bitmap::writeToPng(const char *filename)
 	IMG_SavePNG(p->surface, filename);
 }
 
+void Bitmap::vFlip()
+{
+	guardDisposed();
+	GUARD_MEGA;
+
+	p->flip(IntRect(0, p->gl.height, p->gl.width, -p->gl.height));
+}
+
+void Bitmap::hFlip()
+{
+	guardDisposed();
+	GUARD_MEGA;
+
+	p->flip(IntRect(p->gl.width, 0, -p->gl.width, p->gl.height));
+}
+
 TEXFBO &Bitmap::getGLTypes()
 {
 	return p->gl;

src/bitmap.h

@@ -108,6 +108,9 @@ public:
 	/* extensions */
 	void writeToPng(const char *filename);
 
+	void vFlip();
+	void hFlip();
+
 	/* <internal> */
 	TEXFBO &getGLTypes();
 	SDL_Surface *megaSurface() const;