From 7d16a8c8aa41398a013332841f1a20940fae6d72 Mon Sep 17 00:00:00 2001
From: "Adam D. Ruppe" <destructionator@gmail.com>
Date: Fri, 27 Sep 2013 15:52:34 -0400
Subject: [PATCH] changes for terminal emulator

---
 color.d        | 55 ++++++++++++++++++++++++++++++++++++++----------
 eventloop.d    | 19 ++++++++++++++++-
 stb_truetype.d | 57 +++++++++++++++++++++++++++++++++++++++++---------
 3 files changed, 109 insertions(+), 22 deletions(-)

diff --git a/color.d b/color.d
index 8a57ce2..41234b9 100644
--- a/color.d
+++ b/color.d
@@ -1,5 +1,7 @@
 module arsd.color;
 
+@safe:
+
 // importing phobos explodes the size of this code 10x, so not doing it.
 
 private {
@@ -31,6 +33,7 @@ private {
 		return accumulator + accumulator2 / count;
 	}
 
+	@trusted
 	string toInternal(T)(int a) {
 		if(a == 0)
 			return "0";
@@ -110,10 +113,16 @@ private {
 
 /// Represents an RGBA color
 struct Color {
-	ubyte r; /// red
-	ubyte g; /// green
-	ubyte b; /// blue
-	ubyte a; /// alpha. 255 == opaque
+	union {
+		ubyte[4] components;
+
+		struct {
+			ubyte r; /// red
+			ubyte g; /// green
+			ubyte b; /// blue
+			ubyte a; /// alpha. 255 == opaque
+		}
+	}
 
 	// this makes sure they are in range before casting
 	static Color fromIntegers(int red, int green, int blue, int alpha = 255) {
@@ -126,7 +135,11 @@ struct Color {
 
 	/// .
 	this(int red, int green, int blue, int alpha = 255) {
-		this.r = cast(ubyte) red;
+		// workaround dmd bug 10937
+		if(__ctfe)
+			this.components[0] = cast(ubyte) red;
+		else
+			this.r = cast(ubyte) red;
 		this.g = cast(ubyte) green;
 		this.b = cast(ubyte) blue;
 		this.a = cast(ubyte) alpha;
@@ -764,7 +777,7 @@ class IndexedImage : MemoryImage {
 
 	/// Number of colors currently in the palette (note: palette entries are not necessarily used in the image data)
 	int numColors() const {
-		return palette.length;
+		return cast(int) palette.length;
 	}
 
 	/// Adds an entry to the palette, returning its inded
@@ -790,6 +803,8 @@ class TrueColorImage : MemoryImage {
 		// the union is no good because the length of the struct is wrong!
 
 		/// the same data as Color structs
+		@trusted // the cast here is typically unsafe, but it is ok
+		// here because I guarantee the layout, note the static assert below
 		@property inout(Color)[] colors() inout {
 			return cast(inout(Color)[]) bytes;
 		}
@@ -935,7 +950,7 @@ ubyte findNearestColor(in Color[] palette, in Color pixel) {
 		int dist = dr*dr + dg*dg + db*db;
 
 		if(dist < bestDistance) {
-			best = pe;
+			best = cast(int) pe;
 			bestDistance = dist;
 		}
 	}
@@ -1007,12 +1022,18 @@ img = imageFromPng(readPng(range.range)).getAsTrueColorImage;
 /+
 /// If the background is transparent, it simply erases the alpha channel.
 void removeTransparency(IndexedImage img, Color background)
-
-Color alphaBlend(Color a, Color b) {
-
-}
 +/
 
+Color alphaBlend(Color foreground, Color background) {
+	if(foreground.a != 255)
+	foreach(idx, ref part; foreground.components) {
+		part = cast(ubyte) (part * foreground.a / 255 +
+			background.components[idx] * (255 - foreground.a) / 255);
+	}
+
+	return foreground;
+}
+
 /*
 /// Reduces the number of colors in a palette.
 void reducePaletteSize(IndexedImage img, int maxColors = 16) {
@@ -1065,3 +1086,15 @@ void floydSteinbergDither(IndexedImage img, in TrueColorImage original) {
 		}
 	}
 }
+
+// these are just really useful in a lot of places where the color/image functions are used,
+// so I want them available with Color
+struct Point {
+	int x;
+	int y;
+}
+
+struct Size {
+	int width;
+	int height;
+}
diff --git a/eventloop.d b/eventloop.d
index 6d12de2..68485b0 100644
--- a/eventloop.d
+++ b/eventloop.d
@@ -474,8 +474,25 @@ version(linux) {
 
 			auto nfds = epoll_wait(epoll, events.ptr, events.length, lowestWait);
 			moreEvents:
-			if(nfds == -1)
+			if(nfds == -1) {
+				if(errno == EINTR) {
+					// if we're interrupted, we can just advance the timers (we know none triggered since the timeout didn't go off) and try again
+					if(timers.length) {
+						long prev = tv.tv_sec * 1000 + tv.tv_usec / 1000;
+						gettimeofday(&tv, null);
+						long diff = tv.tv_sec * 1000 + tv.tv_usec / 1000 - prev;
+
+						for(size_t idx = 0; idx < timers.length; idx++) {
+							auto timer = timers[idx];
+							timer.timeoutRemaining -= diff;
+						}
+					}
+
+					continue;
+				}
+
 				throw new Exception("epoll_wait");
+			}
 
 			foreach(n; 0 .. nfds) {
 				auto fd = events[n].data.fd;
diff --git a/stb_truetype.d b/stb_truetype.d
index 3daf654..bd6441b 100644
--- a/stb_truetype.d
+++ b/stb_truetype.d
@@ -18,11 +18,43 @@ struct TtfFont {
 			throw new Exception("load font problem");
 	}
 
-	ubyte[] renderCharacter(dchar c, int size, out int width, out int height) {
-   		auto ptr = stbtt_GetCodepointBitmap(&font, 0.0,stbtt_ScaleForPixelHeight(&font, size), c, &width, &height, null,null);
+	ubyte[] renderCharacter(dchar c, int size, out int width, out int height, float shift_x = 0.0, float shift_y = 0.0) {
+   		auto ptr = stbtt_GetCodepointBitmapSubpixel(&font, 0.0,stbtt_ScaleForPixelHeight(&font, size),
+			shift_x, shift_y, c, &width, &height, null,null);
 		return ptr[0 .. width * height];
 	}
 
+	void getStringSize(string s, int size, out int width, out int height) {
+		float xpos=0;
+
+		auto scale = stbtt_ScaleForPixelHeight(&font, size);
+		int ascent, descent, line_gap;
+		stbtt_GetFontVMetrics(&font, &ascent,&descent,&line_gap);
+		auto baseline = cast(int) (ascent*scale);
+
+		import std.math;
+
+		int maxWidth;
+
+		foreach(i, dchar ch; s) {
+			int advance,lsb;
+			auto x_shift = xpos - floor(xpos);
+			stbtt_GetCodepointHMetrics(&font, ch, &advance, &lsb);
+
+			int x0, y0, x1, y1;
+			stbtt_GetCodepointBitmapBoxSubpixel(&font, ch, scale,scale,x_shift,0, &x0,&y0,&x1,&y1);
+
+			maxWidth = cast(int)(xpos + x1);
+
+			xpos += (advance * scale);
+			if (i + 1 < s.length)
+				xpos += scale*stbtt_GetCodepointKernAdvance(&font, ch,s[i+1]);
+		}
+
+   		width = maxWidth;
+		height = size;
+	}
+
 	ubyte[] renderString(string s, int size, out int width, out int height) {
 		float xpos=0;
 
@@ -33,16 +65,17 @@ struct TtfFont {
 
 		import std.math;
 
-		auto swidth = s.length * size;
-		int sheight = size + baseline + 32;
+		int swidth;
+		int sheight;
+		getStringSize(s, size, swidth, sheight);
 		auto screen = new ubyte[](swidth * sheight);
 
-		foreach(i, ch; s) {
+		foreach(i, dchar ch; s) {
 			int advance,lsb;
 			auto x_shift = xpos - floor(xpos);
 			stbtt_GetCodepointHMetrics(&font, ch, &advance, &lsb);
 			int cw, cheight;
-			auto c = renderCharacter(ch, size, cw, cheight);
+			auto c = renderCharacter(ch, size, cw, cheight, x_shift, 0.0);
 
 			int x0, y0, x1, y1;
 			stbtt_GetCodepointBitmapBoxSubpixel(&font, ch, scale,scale,x_shift,0, &x0,&y0,&x1,&y1);
@@ -56,10 +89,13 @@ struct TtfFont {
 					y++;
 					x = cast(int) xpos + x0;
 				}
-				int val = (pixel * (255 - screen[swidth * y + x]) / 255);
+				auto offset = swidth * y + x;
+				if(offset >= screen.length)
+					break;
+				int val = (cast(int) pixel * (255 - screen[offset]) / 255);
 				if(val > 255)
 					val = 255;
-				screen[swidth * y + x] += cast(ubyte)(val);
+				screen[offset] += cast(ubyte)(val);
 				x++;
 				cx++;
 			}
@@ -85,6 +121,7 @@ struct TtfFont {
 
 
 // test program
+/+
 int main(string[] args)
 {
 import std.conv;
@@ -100,12 +137,12 @@ import std.file;
 
    for (int j=0; j < h; ++j) {
       for (int i=0; i < w; ++i)
-      	img.putPixel(i, j, Color(0, bitmap[j*w+i], 0));
+      	img.putPixel(i, j, Color(0, (bitmap[j*w+i] > 128) ? 255 : 0, 0));
    }
    img.displayImage();
    return 0;
 }
-
++/