Implement Bitmap 'blur'

I was a bit confused at first because I thought Enterbrain
had actually implemented a full Gaussian blur, but nope,
just dumb averaging.

mkxp.pro

@@ -101,10 +101,13 @@ EMBED = shader/transSimple.frag \
         shader/simpleColor.frag \
         shader/simpleAlpha.frag \
         shader/flashMap.frag \
+        shader/blur.frag \
         shader/simple.vert \
         shader/simpleColor.vert \
         shader/sprite.vert \
         shader/simpleMatrix.vert \
+        shader/blurH.vert \
+        shader/blurV.vert \
         assets/liberation.ttf
 
 defineReplace(xxdOutput) {

shader/blur.frag

@@ -0,0 +1,16 @@
+
+uniform sampler2D texture;
+
+varying vec2 v_texCoord;
+varying vec2 v_blurCoord[2];
+
+void main()
+{
+	vec4 frag = vec4(0, 0, 0, 0);
+
+	frag += texture2D(texture, v_texCoord);
+	frag += texture2D(texture, v_blurCoord[0]);
+	frag += texture2D(texture, v_blurCoord[1]);
+
+	gl_FragColor = frag / 3.0;
+}

shader/blurH.vert

@@ -0,0 +1,19 @@
+
+uniform mat4 projMat;
+
+uniform vec2 texSizeInv;
+
+attribute vec2 position;
+attribute vec2 texCoord;
+
+varying vec2 v_texCoord;
+varying vec2 v_blurCoord[2];
+
+void main()
+{
+	gl_Position = projMat * vec4(position, 0, 1);
+
+	v_texCoord = texCoord * texSizeInv;
+	v_blurCoord[0] = vec2(texCoord.x-1, texCoord.y) * texSizeInv;
+	v_blurCoord[1] = vec2(texCoord.x+1, texCoord.y) * texSizeInv;
+}

shader/blurV.vert

@@ -0,0 +1,19 @@
+
+uniform mat4 projMat;
+
+uniform vec2 texSizeInv;
+
+attribute vec2 position;
+attribute vec2 texCoord;
+
+varying vec2 v_texCoord;
+varying vec2 v_blurCoord[2];
+
+void main()
+{
+	gl_Position = projMat * vec4(position, 0, 1);
+
+	v_texCoord = texCoord * texSizeInv;
+	v_blurCoord[0] = vec2(texCoord.x, texCoord.y-1) * texSizeInv;
+	v_blurCoord[1] = vec2(texCoord.x, texCoord.y+1) * texSizeInv;
+}

src/bitmap.cpp

@@ -508,6 +508,53 @@ void Bitmap::clearRect(const IntRect &rect)
 	modified();
 }
 
+void Bitmap::blur()
+{
+	GUARD_DISPOSED;
+
+	GUARD_MEGA;
+
+	flush();
+
+	Quad &quad = gState->gpQuad();
+	FloatRect rect(0, 0, width(), height());
+	quad.setTexPosRect(rect, rect);
+
+	TEXFBO auxTex = gState->texPool().request(width(), height());
+
+	BlurShader &shader = gState->blurShader();
+	BlurShader::HPass &pass1 = shader.pass1;
+	BlurShader::VPass &pass2 = shader.pass2;
+
+	glState.blendMode.pushSet(BlendNone);
+	glState.viewport.pushSet(IntRect(0, 0, width(), height()));
+
+	TEX::bind(p->tex.tex);
+	FBO::bind(auxTex.fbo, FBO::Draw);
+
+	pass1.bind();
+	pass1.setTexSize(Vec2i(width(), height()));
+	pass1.applyViewportProj();
+
+	quad.draw();
+
+	TEX::bind(auxTex.tex);
+	FBO::bind(p->tex.fbo, FBO::Draw);
+
+	pass2.bind();
+	pass2.setTexSize(Vec2i(width(), height()));
+	pass2.applyViewportProj();
+
+	quad.draw();
+
+	glState.viewport.pop();
+	glState.blendMode.pop();
+
+	gState->texPool().release(auxTex);
+
+	modified();
+}
+
 void Bitmap::radialBlur(int angle, int divisions)
 {
 	GUARD_DISPOSED;

src/bitmap.h

@@ -74,8 +74,10 @@ public:
 	               int width, int height);
 	void clearRect(const IntRect &rect);
 
+	void blur();
+
 	void radialBlur(int angle, int divisions);
-//	/* ----- */
+	/* ----- */
 
 	void clear();
 

src/globalstate.cpp

@@ -76,6 +76,7 @@ struct GlobalStatePrivate
 	TransShader transShader;
 	SimpleTransShader sTransShader;
 	HueShader hueShader;
+	BlurShader blurShader;
 	BltShader bltShader;
 
 	TexPool texPool;
@@ -196,6 +197,7 @@ GSATT(FlashMapShader&, flashMapShader)
 GSATT(TransShader&, transShader)
 GSATT(SimpleTransShader&, sTransShader)
 GSATT(HueShader&, hueShader)
+GSATT(BlurShader&, blurShader)
 GSATT(BltShader&, bltShader)
 GSATT(TexPool&, texPool)
 GSATT(FontPool&, fontPool)

src/globalstate.h

@@ -57,6 +57,7 @@ class BltShader;
 class TexPool;
 class FontPool;
 class Font;
+struct BlurShader;
 struct GlobalIBO;
 struct Config;
 struct Vec2i;
@@ -94,6 +95,7 @@ struct GlobalState
 	TransShader &transShader();
 	SimpleTransShader &sTransShader();
 	HueShader &hueShader();
+	BlurShader &blurShader();
 	BltShader &bltShader();
 
 	TexPool &texPool();

src/shader.cpp

@@ -37,10 +37,13 @@
 #include "../simpleColor.frag.xxd"
 #include "../simpleAlpha.frag.xxd"
 #include "../flashMap.frag.xxd"
+#include "../blur.frag.xxd"
 #include "../simple.vert.xxd"
 #include "../simpleColor.vert.xxd"
 #include "../sprite.vert.xxd"
 #include "../simpleMatrix.vert.xxd"
+#include "../blurH.vert.xxd"
+#include "../blurV.vert.xxd"
 
 
 #define INIT_SHADER(vert, frag) \
@@ -422,6 +425,22 @@ void HueShader::setInputTexture(TEX::ID tex)
 }
 
 
+BlurShader::HPass::HPass()
+{
+	INIT_SHADER(blurH, blur);
+
+	ShaderBase::init();
+}
+
+BlurShader::VPass::VPass()
+{
+	INIT_SHADER(blurV, blur);
+
+	ShaderBase::init();
+}
+
+
+
 BltShader::BltShader()
 {
 	INIT_SHADER(simple, bitmapBlit);

src/shader.h

@@ -210,6 +210,25 @@ private:
 	GLint u_hueAdjust, u_inputTexture;
 };
 
+/* Gaussian blur */
+struct BlurShader
+{
+	class HPass : public ShaderBase
+	{
+	public:
+		HPass();
+	};
+
+	class VPass : public ShaderBase
+	{
+	public:
+		VPass();
+	};
+
+	HPass pass1;
+	VPass pass2;
+};
+
 /* Bitmap blit */
 class BltShader : public ShaderBase
 {