Add GetAverageColor to RageTexture

a neat little graphics utility function

Author: poco0317

src/RageUtil/Graphics/RageBitmapTexture.cpp

@@ -358,6 +358,21 @@ RageBitmapTexture::Create()
 		}
 	}
 
+	// Precalculate the average color of the texture if needed at any point
+	// we can't construct it from the texhandle (or can we?)
+	RageColor rc(0, 0, 0, 1);
+	if (pImg != nullptr) {
+		uint8_t r = 0, g = 0, b = 0;
+		RageSurfaceUtils::GetAverageRGB(pImg, r, g, b);
+		float rF = r / 255.F;
+		float gF = g / 255.F;
+		float bF = b / 255.F;
+		rc.r = rF;
+		rc.g = gF;
+		rc.b = bF;
+	}
+	averageColor = rc;
+
 	delete pImg;
 
 	// Check for hints that override the apparent "size".

src/RageUtil/Graphics/RageBitmapTexture.h

@@ -1,4 +1,4 @@
-/* RageBitmapTexture - Loads a static texture. */
+/* RageBitmapTexture - Loads a static texture. */
 
 #ifndef RAGEBITMAPTEXTURE_H
 #define RAGEBITMAPTEXTURE_H
@@ -18,10 +18,16 @@ class RageBitmapTexture : public RageTexture
 		return m_uTexHandle;
 	}; // accessed by RageDisplay
 
+	auto GetAverageColor() const -> const RageColor override
+	{
+		return averageColor;
+	}
+
   private:
 	void Create(); // called by constructor and Reload
 	void Destroy();
 	intptr_t m_uTexHandle; // treat as unsigned in OpenGL, ID3D8Texture* for D3D
+	RageColor averageColor{ 0, 0, 0, 1 };
 };
 
 #endif

src/RageUtil/Graphics/RageSurfaceUtils.cpp

@@ -200,6 +200,50 @@ RageSurfaceUtils::ConvertSurface(RageSurface*& image,
 	image = ret_image;
 }
 
+void
+RageSurfaceUtils::GetAverageRGB(const RageSurface* img, uint8_t& r, uint8_t& g, uint8_t& b)
+{
+	uint64_t rt = 0;
+	uint64_t gt = 0;
+	uint64_t bt = 0;
+
+	uint8_t tempR = 0;
+	uint8_t tempG = 0;
+	uint8_t tempB = 0;
+
+	uint64_t pixelCount = 0;
+
+	for (auto y = 0; y < img->h; ++y) {
+		auto row = static_cast<uint8_t*>(img->pixels) + img->pitch * y;
+
+		for (auto x = 0; x < img->w; ++x) {
+			const auto val = decodepixel(row, img->fmt.BytesPerPixel);
+			if (img->fmt.BitsPerPixel == 8) {
+				if (img->fmt.palette->colors[val].a) {
+					// This color isn't fully transparent, so grab it.
+					rt += img->fmt.palette->colors[val].r;
+					gt += img->fmt.palette->colors[val].g;
+					bt += img->fmt.palette->colors[val].b;
+				}
+			} else {
+				if (val & img->fmt.Amask) {
+					// This color isn't fully transparent, so grab it.
+					img->fmt.GetRGB(val, &tempR, &tempG, &tempB);
+					rt += tempR;
+					gt += tempG;
+					bt += tempB;
+				}
+			}
+
+			row += img->fmt.BytesPerPixel;
+			pixelCount++;
+		}
+	}
+	r = rt / pixelCount;
+	g = gt / pixelCount;
+	b = gt / pixelCount;
+}
+
 // Local helper for FixHiddenAlpha.
 static void
 FindAlphaRGB(const RageSurface* img,

src/RageUtil/Graphics/RageSurfaceUtils.h

@@ -59,6 +59,12 @@ ConvertSurface(RageSurface*& image,
 			   uint32_t B,
 			   uint32_t A);
 
+void
+GetAverageRGB(const RageSurface* img,
+			   uint8_t& r,
+			   uint8_t& g,
+			   uint8_t& b);
+
 void
 FixHiddenAlpha(RageSurface* img);
 

src/RageUtil/Graphics/RageTexture.cpp

@@ -137,6 +137,12 @@ class LunaRageTexture : public Luna<RageTexture>
 		p->Reload();
 		COMMON_RETURN_SELF;
 	}
+	static int GetAverageColor(T* p, lua_State* L)
+	{
+		// will return the average color of the texture independent of diffuse
+		p->GetAverageColor().PushTable(L);
+		return 1;
+	}
 	DEFINE_METHOD(GetSourceWidth, GetSourceWidth());
 	DEFINE_METHOD(GetSourceHeight, GetSourceHeight());
 	DEFINE_METHOD(GetTextureWidth, GetTextureWidth());
@@ -160,6 +166,7 @@ class LunaRageTexture : public Luna<RageTexture>
 		ADD_METHOD(GetImageWidth);
 		ADD_METHOD(GetImageHeight);
 		ADD_METHOD(GetPath);
+		ADD_METHOD(GetAverageColor);
 	}
 };
 

src/RageUtil/Graphics/RageTexture.h

@@ -123,6 +123,11 @@ class RageTexture
 											   int source_width = 0,
 											   int source_height = 0);
 
+	virtual auto GetAverageColor() const -> const RageColor
+	{
+		return RageColor(0, 0, 0, 1);
+	}
+
 	// Lua
 	virtual void PushSelf(lua_State* L);
 

src/arch/MovieTexture/MovieTexture_Generic.cpp

@@ -1,5 +1,6 @@
 #include "Etterna/Globals/global.h"
 #include "MovieTexture_Generic.h"
+#include "RageUtil/Graphics/RageSurfaceUtils.h"
 #include "Etterna/Singletons/PrefsManager.h"
 #include "RageUtil/Graphics/RageDisplay.h"
 #include "Core/Services/Locator.hpp"
@@ -531,3 +532,20 @@ MovieTexture_Generic::GetTexHandle() const
 
 	return m_uTexHandle;
 }
+
+auto
+MovieTexture_Generic::GetAverageColor() const -> const RageColor
+{
+	RageColor rc(0,0,0,1);
+	if (m_pSurface != nullptr) {
+		uint8_t r = 0, g = 0, b = 0;
+		RageSurfaceUtils::GetAverageRGB(m_pSurface, r, g, b);
+		float rF = r / 255.F;
+		float gF = g / 255.F;
+		float bF = b / 255.F;
+		rc.r = rF;
+		rc.g = gF;
+		rc.b = bF;
+	}
+	return rc;
+}

src/arch/MovieTexture/MovieTexture_Generic.h

@@ -99,6 +99,9 @@ class MovieTexture_Generic : public RageMovieTexture
 
 	static EffectMode GetEffectMode(MovieDecoderPixelFormatYCbCr fmt);
 
+	auto GetAverageColor() const -> const RageColor override;
+
+
   private:
 	MovieDecoder* m_pDecoder;