Text drawing now uses an AColor instead of a normal Color, so transparent text is possible.

doc/type/font.txt

@@ -15,7 +15,7 @@ A reference to a normal [[type:font]] for drawing text.
 | @style@		[[type:scriptable]] font style		@"normal"@	Style of the font, one of @"normal"@ or @"italic"@. This can be changed locally by [[type:tagged string|tags]].
 | @underline@		[[type:scriptable]] [[type:boolean]]	@false@		Should the font be underlined?
 | @color@		[[type:scriptable]] [[type:color]]	@rgb(0,0,0)@	What color should text be drawn in?
-| @shadow color@	[[type:scriptable]] [[type:color]]	@rgb(0,0,0)@	Color for a shadow below the text.
+| @shadow color@	[[type:scriptable]] [[type:color]]	@"transparent"@	Color for a shadow below the text.
 | @shadow displacement x@	[[type:double]]			@0@		Relative position of the shadow in pixels. A shadow is only drawn if the displacement is nonzero.
 | @shadow displacement y@	[[type:double]]			@0@		^^^
 | @shadow blur@		[[type:double]]				@0@		How much should the shadow be blurred?

src/data/font.cpp

@@ -17,6 +17,7 @@ Font::Font()
 	, underline(false)
 	, scale_down_to(100000)
 	, max_stretch(1.0)
+	, color(AColor(0,0,0))
 	, shadow_displacement(0,0)
 	, shadow_blur(0)
 	, separator_color(128,128,128)

src/data/font.hpp

@@ -12,6 +12,7 @@
 #include <util/prec.hpp>
 #include <util/real_point.hpp>
 #include <script/scriptable.hpp>
+#include <gfx/color.hpp>
 
 DECLARE_POINTER_TYPE(Font);
 
@@ -40,8 +41,8 @@ class Font : public IntrusivePtrBase<Font> {
 	Scriptable<bool>   underline;			///< Underlined?
 	double             scale_down_to;		///< Smallest size to scale down to
 	double             max_stretch;			///< How much should the font be stretched before scaling down?
-	Scriptable<Color>  color;				///< Color to use
-	Scriptable<Color>  shadow_color;		///< Color for shadow
+	Scriptable<AColor> color;				///< Color to use
+	Scriptable<AColor> shadow_color;		///< Color for shadow
 	RealSize           shadow_displacement;	///< Position of the shadow
 	double             shadow_blur;			///< Blur radius of the shadow
 	Color              separator_color;		///< Color for <sep> text

src/gfx/gfx.hpp

@@ -52,7 +52,7 @@ void sharp_resample_and_clip(const Image& img_in, Image& img_out, wxRect rect, i
  *  rect    = rectangle to draw in (a rectangle somewhere around pos)
  *  stretch = amount to stretch in the direction of the text after drawing
  */
-void draw_resampled_text(DC& dc, const RealPoint& pos, const RealRect& rect, double stretch, int angle, const String& text, int blur_radius = 0, int repeat = 1);
+void draw_resampled_text(DC& dc, const RealPoint& pos, const RealRect& rect, double stretch, int angle, AColor color, const String& text, int blur_radius = 0, int repeat = 1);
 
 // scaling factor to use when drawing resampled text
 extern const int text_scaling;

src/gfx/resample_text.cpp

@@ -165,7 +165,9 @@ void blur_image_alpha(Image& img) {
 
 // Draw text by first drawing it using a larger font and then downsampling it
 // optionally rotated by an angle
-void draw_resampled_text(DC& dc, const RealPoint& pos, const RealRect& rect, double stretch, int angle, const String& text, int blur_radius, int repeat) {
+void draw_resampled_text(DC& dc, const RealPoint& pos, const RealRect& rect, double stretch, int angle, AColor color, const String& text, int blur_radius, int repeat) {
+	// transparent text can be ignored
+	if (color.alpha == 0) return;
 	// enlarge slightly; some fonts are larger then the GetTextExtent tells us (especially italic fonts)
 	int w = static_cast<int>(rect.width) + 3 + 2 * blur_radius, h = static_cast<int>(rect.height) + 1 + 2 * blur_radius;
 	// determine sub-pixel position
@@ -188,8 +190,12 @@ void draw_resampled_text(DC& dc, const RealPoint& pos, const RealRect& rect, dou
 	if (!sideways(angle)) w = int(w * stretch); // GCC makes annoying conversion warnings if *= is used here.
 	else                  h = int(h * stretch);
 	Image img_small(w, h, false);
-	fill_image(img_small, dc.GetTextForeground());
+	fill_image(img_small, color);
 	downsample_to_alpha(buffer, img_small);
+	// multiply alpha
+	if (color.alpha != 255) {
+		set_alpha(img_small, color.alpha / 255.);
+	}
 	// blur
 	for (int i = 0 ; i < blur_radius ; ++i) {
 		blur_image_alpha(img_small);

src/util/rotation.cpp

@@ -199,7 +199,12 @@ RotatedDC::RotatedDC(DC& dc, const Rotation& rotation, RenderQuality quality)
 // ----------------------------------------------------------------------------- : RotatedDC : Drawing
 
 void RotatedDC::DrawText  (const String& text, const RealPoint& pos, int blur_radius, int boldness, double stretch_) {
+	DrawText(text, pos, dc.GetTextForeground(), blur_radius, boldness, stretch_);
+}
+
+void RotatedDC::DrawText  (const String& text, const RealPoint& pos, AColor color, int blur_radius, int boldness, double stretch_) {
 	if (text.empty()) return;
+	if (color.alpha == 0) return;
 	if (quality >= QUALITY_AA) {
 		RealRect r(pos, GetTextExtent(text));
 		RealRect r_ext = trRectToBB(r);
@@ -212,27 +217,25 @@ void RotatedDC::DrawText  (const String& text, const RealPoint& pos, int blur_ra
 			r_ext.x = r_ext2.x;
 			r_ext.y = r_ext2.y;
 		}
-		draw_resampled_text(dc, pos2, r_ext, stretch_ * getStretch(), angle, text, blur_radius, boldness);
+		draw_resampled_text(dc, pos2, r_ext, stretch_ * getStretch(), angle, color, text, blur_radius, boldness);
 	} else if (quality >= QUALITY_SUB_PIXEL) {
 		RealPoint p_ext = tr(pos)*text_scaling;
 		double usx,usy;
 		dc.GetUserScale(&usx, &usy);
 		dc.SetUserScale(usx/text_scaling, usy/text_scaling);
+		dc.SetTextForeground(color);
 		dc.DrawRotatedText(text, (int) p_ext.x, (int) p_ext.y, angle);
 		dc.SetUserScale(usx, usy);
 	} else {
 		RealPoint p_ext = tr(pos);
+		dc.SetTextForeground(color);
 		dc.DrawRotatedText(text, (int) p_ext.x, (int) p_ext.y, angle);
 	}
 }
 
 void RotatedDC::DrawTextWithShadow(const String& text, const Font& font, const RealPoint& pos, double scale, double stretch) {
-	if (font.hasShadow()) {
-		SetTextForeground(font.shadow_color);
-		DrawText(text, pos + font.shadow_displacement * scale, font.shadow_blur * scale, 1, stretch);
-	}
-	SetTextForeground(font.color);
-	DrawText(text, pos, 0, 1, stretch);
+	DrawText(text, pos + font.shadow_displacement * scale, font.shadow_color, font.shadow_blur * scale, 1, stretch);
+	DrawText(text, pos, font.color, 0, 1, stretch);
 }
 
 void RotatedDC::DrawBitmap(const Bitmap& bitmap, const RealPoint& pos) {

src/util/rotation.hpp

@@ -164,7 +164,8 @@ class RotatedDC : public Rotation {
 	// --------------------------------------------------- : Drawing
 	
 	/// Draw text
-	void DrawText  (const String& text,   const RealPoint& pos, int blur_radius = 0, int boldness = 1, double stretch = 1.0);
+	void DrawText  (const String& text, const RealPoint& pos,               int blur_radius = 0, int boldness = 1, double stretch = 1.0);
+	void DrawText  (const String& text, const RealPoint& pos, AColor color, int blur_radius = 0, int boldness = 1, double stretch = 1.0);
 	/// Draw text with the shadow and color settings of the given font
 	void DrawTextWithShadow(const String& text, const Font& font, const RealPoint& pos, double scale = 1.0, double stretch = 1.0);
 	/// Draw abitmap, it must already be zoomed!