(svn r25911) -Add: Support for drawing dashed lines.

4 files changed, 18 insertions, 11 deletions

diff --git a/src/blitter/base.cpp b/src/blitter/base.cpp
index bb8b9f234..d30f4054b 100644
--- a/src/blitter/base.cpp
+++ b/src/blitter/base.cpp
@@ -13,7 +13,7 @@
 #include "base.hpp"
 #include "../core/math_func.hpp"
 
-void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width)
+void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash)
 {
 	int dy;
 	int dx;
@@ -59,6 +59,9 @@ void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_wid
 		}
 	}
 
+	int gap = dash;
+	if (dash == 0) dash = 1;
+	int dash_count = 0;
 	if (dx > dy) {
 		int y_low     = y;
 		int y_high    = y;
@@ -76,7 +79,7 @@ void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_wid
 		x2 += stepx;
 
 		while (x != x2) {
-			if (x >= 0 && x < screen_width) {
+			if (dash_count < dash && x >= 0 && x < screen_width) {
 				for (int y = y_low; y != y_high; y += stepy) {
 					if (y >= 0 && y < screen_height) this->SetPixel(video, x, y, colour);
 				}
@@ -92,6 +95,7 @@ void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_wid
 			x += stepx;
 			frac_low += dy;
 			frac_high += dy;
+			if (++dash_count >= dash + gap) dash_count = 0;
 		}
 	} else {
 		int x_low     = x;
@@ -110,7 +114,7 @@ void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_wid
 		y2 += stepy;
 
 		while (y != y2) {
-			if (y >= 0 && y < screen_height) {
+			if (dash_count < dash && y >= 0 && y < screen_height) {
 				for (int x = x_low; x != x_high; x += stepx) {
 					if (x >= 0 && x < screen_width) this->SetPixel(video, x, y, colour);
 				}
@@ -126,6 +130,7 @@ void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_wid
 			y += stepy;
 			frac_low += dx;
 			frac_high += dx;
+			if (++dash_count >= dash + gap) dash_count = 0;
 		}
 	}
 }
diff --git a/src/blitter/base.hpp b/src/blitter/base.hpp
index 91ff68c3b..00851eeef 100644
--- a/src/blitter/base.hpp
+++ b/src/blitter/base.hpp
@@ -118,8 +118,9 @@ public:
 	 * @param screen_height The height of the screen you are drawing in (to avoid buffer-overflows).
 	 * @param colour A 8bpp mapping colour.
 	 * @param width Line width.
+	 * @param dash Length of dashes for dashed lines. 0 means solid line.
 	 */
-	virtual void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width);
+	virtual void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash = 0);
 
 	/**
 	 * Copy from a buffer to the screen.
diff --git a/src/gfx.cpp b/src/gfx.cpp
index aa81f99f8..ecb2e7643 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -162,8 +162,9 @@ void GfxFillRect(int left, int top, int right, int bottom, int colour, FillRectM
  * @param screen_height Height of the screen to check clipping against.
  * @param colour Colour of the line.
  * @param width Width of the line.
+ * @param dash Length of dashes for dashed lines. 0 means solid line.
  */
-static inline void GfxDoDrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width)
+static inline void GfxDoDrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash = 0)
 {
 	Blitter *blitter = BlitterFactoryBase::GetCurrentBlitter();
 
@@ -174,7 +175,7 @@ static inline void GfxDoDrawLine(void *video, int x, int y, int x2, int y2, int
 		blitter->DrawLine(video,
 				Clamp(x, 0, screen_width), y,
 				Clamp(x2, 0, screen_width), y2,
-				screen_width, screen_height, colour, width);
+				screen_width, screen_height, colour, width, dash);
 		return;
 	}
 	if (x2 == x) {
@@ -182,7 +183,7 @@ static inline void GfxDoDrawLine(void *video, int x, int y, int x2, int y2, int
 		blitter->DrawLine(video,
 				x, Clamp(y, 0, screen_height),
 				x2, Clamp(y2, 0, screen_height),
-				screen_width, screen_height, colour, width);
+				screen_width, screen_height, colour, width, dash);
 		return;
 	}
 
@@ -212,7 +213,7 @@ static inline void GfxDoDrawLine(void *video, int x, int y, int x2, int y2, int
 	 * of rounding errors so much additional code has to be run here that in
 	 * the general case the effect is not noticable. */
 
-	blitter->DrawLine(video, x, y, x2, y2, screen_width, screen_height, colour, width);
+	blitter->DrawLine(video, x, y, x2, y2, screen_width, screen_height, colour, width, dash);
 }
 
 /**
@@ -241,11 +242,11 @@ static inline bool GfxPreprocessLine(DrawPixelInfo *dpi, int &x, int &y, int &x2
 	return true;
 }
 
-void GfxDrawLine(int x, int y, int x2, int y2, int colour, int width)
+void GfxDrawLine(int x, int y, int x2, int y2, int colour, int width, int dash)
 {
 	DrawPixelInfo *dpi = _cur_dpi;
 	if (GfxPreprocessLine(dpi, x, y, x2, y2, width)) {
-		GfxDoDrawLine(dpi->dst_ptr, x, y, x2, y2, dpi->width, dpi->height, colour, width);
+		GfxDoDrawLine(dpi->dst_ptr, x, y, x2, y2, dpi->width, dpi->height, colour, width, dash);
 	}
 }
 
diff --git a/src/gfx_func.h b/src/gfx_func.h
index 709fc2cc9..69d2e4570 100644
--- a/src/gfx_func.h
+++ b/src/gfx_func.h
@@ -118,7 +118,7 @@ int DrawStringMultiLine(int left, int right, int top, int bottom, StringID str,
 void DrawCharCentered(uint32 c, int x, int y, TextColour colour);
 
 void GfxFillRect(int left, int top, int right, int bottom, int colour, FillRectMode mode = FILLRECT_OPAQUE);
-void GfxDrawLine(int left, int top, int right, int bottom, int colour, int width = 1);
+void GfxDrawLine(int left, int top, int right, int bottom, int colour, int width = 1, int dash = 0);
 void DrawBox(int x, int y, int dx1, int dy1, int dx2, int dy2, int dx3, int dy3);
 
 Dimension GetStringBoundingBox(const char *str, FontSize start_fontsize = FS_NORMAL);