Feature [feature-requests:#1402]. Unify colour type with ColourAlpha.

Change ColourDesired to ColourAlpha in XPM and RGBAImage.

3 files changed, 28 insertions, 35 deletions

diff --git a/src/Indicator.cxx b/src/Indicator.cxx
index 1ebc18b7f..f65b461ef 100644
--- a/src/Indicator.cxx
+++ b/src/Indicator.cxx
@@ -74,17 +74,19 @@ void Indicator::Draw(Surface *surface, const PRectangle &rc, const PRectangle &r
 
 			const int width = std::min(4000, static_cast<int>(rcSquiggle.Width()));
 			RGBAImage image(width, 3, 1.0, nullptr);
-			enum { alphaFull = 0xff, alphaSide = 0x2f, alphaSide2=0x5f };
+			constexpr unsigned int alphaFull = 0xff;
+			constexpr unsigned int alphaSide = 0x2f;
+			constexpr unsigned int alphaSide2 = 0x5f;
 			for (int x = 0; x < width; x++) {
 				if (x%2) {
 					// Two halfway columns have a full pixel in middle flanked by light pixels
-					image.SetPixel(x, 0, sacDraw.fore, alphaSide);
-					image.SetPixel(x, 1, sacDraw.fore, alphaFull);
-					image.SetPixel(x, 2, sacDraw.fore, alphaSide);
+					image.SetPixel(x, 0, ColourAlpha(sacDraw.fore, alphaSide));
+					image.SetPixel(x, 1, ColourAlpha(sacDraw.fore, alphaFull));
+					image.SetPixel(x, 2, ColourAlpha(sacDraw.fore, alphaSide));
 				} else {
 					// Extreme columns have a full pixel at bottom or top and a mid-tone pixel in centre
-					image.SetPixel(x, (x % 4) ? 0 : 2, sacDraw.fore, alphaFull);
-					image.SetPixel(x, 1, sacDraw.fore, alphaSide2);
+					image.SetPixel(x, (x % 4) ? 0 : 2, ColourAlpha(sacDraw.fore, alphaFull));
+					image.SetPixel(x, 1, ColourAlpha(sacDraw.fore, alphaSide2));
 				}
 			}
 			surface->DrawRGBAImage(rcSquiggle, image.GetWidth(), image.GetHeight(), image.Pixels());
@@ -207,13 +209,13 @@ void Indicator::Draw(Surface *surface, const PRectangle &rc, const PRectangle &r
 			// Draw horizontal lines top and bottom
 			for (int x=0; x<width; x++) {
 				for (int y = 0; y< height; y += height - 1) {
-					image.SetPixel(x, y, sacDraw.fore, ((x + y) % 2) ? outlineAlpha : fillAlpha);
+					image.SetPixel(x, y, ColourAlpha(sacDraw.fore, ((x + y) % 2) ? outlineAlpha : fillAlpha));
 				}
 			}
 			// Draw vertical lines left and right
 			for (int y = 1; y<height; y++) {
 				for (int x=0; x<width; x += width-1) {
-					image.SetPixel(x, y, sacDraw.fore, ((x + y) % 2) ? outlineAlpha : fillAlpha);
+					image.SetPixel(x, y, ColourAlpha(sacDraw.fore, ((x + y) % 2) ? outlineAlpha : fillAlpha));
 				}
 			}
 			surface->DrawRGBAImage(rcBox, image.GetWidth(), image.GetHeight(), image.Pixels());
diff --git a/src/XPM.cxx b/src/XPM.cxx
index c310911f6..ef2ba961a 100644
--- a/src/XPM.cxx
+++ b/src/XPM.cxx
@@ -60,17 +60,17 @@ unsigned int ValueOfHex(const char ch) noexcept {
 		return 0;
 }
 
-ColourDesired ColourFromHex(const char *val) noexcept {
+ColourAlpha ColourFromHex(const char *val) noexcept {
 	const unsigned int r = ValueOfHex(val[0]) * 16 + ValueOfHex(val[1]);
 	const unsigned int g = ValueOfHex(val[2]) * 16 + ValueOfHex(val[3]);
 	const unsigned int b = ValueOfHex(val[4]) * 16 + ValueOfHex(val[5]);
-	return ColourDesired(r, g, b);
+	return ColourAlpha(r, g, b);
 }
 
 }
 
 
-ColourDesired XPM::ColourFromCode(int ch) const noexcept {
+ColourAlpha XPM::ColourFromCode(int ch) const noexcept {
 	return colourCodeTable[ch];
 }
 
@@ -116,7 +116,7 @@ void XPM::Init(const char *const *linesForm) {
 	if (!linesForm)
 		return;
 
-	std::fill(colourCodeTable, std::end(colourCodeTable), ColourDesired(0));
+	std::fill(colourCodeTable, std::end(colourCodeTable), ColourAlpha(0, 0, 0));
 	const char *line0 = linesForm[0];
 	width = atoi(line0);
 	line0 = NextField(line0);
@@ -134,7 +134,7 @@ void XPM::Init(const char *const *linesForm) {
 		const char *colourDef = linesForm[c+1];
 		const char code = colourDef[0];
 		colourDef += 4;
-		ColourDesired colour(0xff, 0xff, 0xff);
+		ColourAlpha colour(0, 0, 0, 0);
 		if (*colourDef == '#') {
 			colour = ColourFromHex(colourDef+1);
 		} else {
@@ -173,19 +173,13 @@ void XPM::Draw(Surface *surface, const PRectangle &rc) {
 	}
 }
 
-void XPM::PixelAt(int x, int y, ColourDesired &colour, bool &transparent) const noexcept {
-	if (pixels.empty() || (x<0) || (x >= width) || (y<0) || (y >= height)) {
-		colour = ColourDesired(0);
-		transparent = true;
-		return;
+ColourAlpha XPM::PixelAt(int x, int y) const noexcept {
+	if (pixels.empty() || (x < 0) || (x >= width) || (y < 0) || (y >= height)) {
+		// Out of bounds -> transparent black
+		return ColourAlpha(0, 0, 0, 0);
 	}
 	const int code = pixels[y * width + x];
-	transparent = code == codeTransparent;
-	if (transparent) {
-		colour = ColourDesired(0);
-	} else {
-		colour = ColourFromCode(code);
-	}
+	return ColourFromCode(code);
 }
 
 std::vector<const char *> XPM::LinesFormFromTextForm(const char *textForm) {
@@ -239,10 +233,7 @@ RGBAImage::RGBAImage(const XPM &xpm) {
 	pixelBytes.resize(CountBytes());
 	for (int y=0; y<height; y++) {
 		for (int x=0; x<width; x++) {
-			ColourDesired colour;
-			bool transparent = false;
-			xpm.PixelAt(x, y, colour, transparent);
-			SetPixel(x, y, colour, transparent ? 0 : 255);
+			SetPixel(x, y, xpm.PixelAt(x, y));
 		}
 	}
 }
@@ -258,13 +249,13 @@ const unsigned char *RGBAImage::Pixels() const noexcept {
 	return &pixelBytes[0];
 }
 
-void RGBAImage::SetPixel(int x, int y, ColourDesired colour, int alpha) noexcept {
-	unsigned char *pixel = &pixelBytes[0] + (y*width+x) * 4;
+void RGBAImage::SetPixel(int x, int y, ColourAlpha colour) noexcept {
+	unsigned char *pixel = &pixelBytes[0] + (y * width + x) * 4;
 	// RGBA
 	pixel[0] = colour.GetRed();
 	pixel[1] = colour.GetGreen();
 	pixel[2] = colour.GetBlue();
-	pixel[3] = static_cast<unsigned char>(alpha);
+	pixel[3] = colour.GetAlpha();
 }
 
 // Transform a block of pixels from RGBA to BGRA with premultiplied alpha.
diff --git a/src/XPM.h b/src/XPM.h
index cacae9b8a..3f7b66b9a 100644
--- a/src/XPM.h
+++ b/src/XPM.h
@@ -18,9 +18,9 @@ class XPM {
 	int width=1;
 	int nColours=1;
 	std::vector<unsigned char> pixels;
-	ColourDesired colourCodeTable[256];
+	ColourAlpha colourCodeTable[256];
 	char codeTransparent=' ';
-	ColourDesired ColourFromCode(int ch) const noexcept;
+	ColourAlpha ColourFromCode(int ch) const noexcept;
 	void FillRun(Surface *surface, int code, int startX, int y, int x) const;
 public:
 	explicit XPM(const char *textForm);
@@ -36,7 +36,7 @@ public:
 	void Draw(Surface *surface, const PRectangle &rc);
 	int GetHeight() const noexcept { return height; }
 	int GetWidth() const noexcept { return width; }
-	void PixelAt(int x, int y, ColourDesired &colour, bool &transparent) const noexcept;
+	ColourAlpha PixelAt(int x, int y) const noexcept;
 private:
 	static std::vector<const char *>LinesFormFromTextForm(const char *textForm);
 };
@@ -65,7 +65,7 @@ public:
 	float GetScaledWidth() const noexcept { return width / scale; }
 	int CountBytes() const noexcept;
 	const unsigned char *Pixels() const noexcept;
-	void SetPixel(int x, int y, ColourDesired colour, int alpha) noexcept;
+	void SetPixel(int x, int y, ColourAlpha colour) noexcept;
 	static void BGRAFromRGBA(unsigned char *pixelsBGRA, const unsigned char *pixelsRGBA, size_t count) noexcept;
 };