1 files changed, 275 insertions, 0 deletions
diff --git a/widgets/drawille-go/drawille.go b/widgets/drawille-go/drawille.go
new file mode 100644
index 0000000..f9954d0
--- /dev/null
+++ b/widgets/drawille-go/drawille.go
@@ -0,0 +1,275 @@
+package drawille
+
+//import "code.google.com/p/goncurses"
+import "math"
+
+var pixel_map = [4][2]int{
+	{0x1, 0x8},
+	{0x2, 0x10},
+	{0x4, 0x20},
+	{0x40, 0x80}}
+
+// Braille chars start at 0x2800
+var braille_char_offset = 0x2800
+
+func getPixel(y, x int) int {
+	var cy, cx int
+	if y >= 0 {
+		cy = y % 4
+	} else {
+		cy = 3 + ((y + 1) % 4)
+	}
+	if x >= 0 {
+		cx = x % 2
+	} else {
+		cx = 1 + ((x + 1) % 2)
+	}
+	return pixel_map[cy][cx]
+}
+
+type Canvas struct {
+	LineEnding string
+	chars      map[int]map[int]int
+}
+
+// Make a new canvas
+func NewCanvas() Canvas {
+	c := Canvas{LineEnding: "\n"}
+	c.Clear()
+	return c
+}
+
+func (c Canvas) MaxY() int {
+	max := 0
+	for k, _ := range c.chars {
+		if k > max {
+			max = k
+		}
+	}
+	return max * 4
+}
+
+func (c Canvas) MinY() int {
+	min := 0
+	for k, _ := range c.chars {
+		if k < min {
+			min = k
+		}
+	}
+	return min * 4
+}
+
+func (c Canvas) MaxX() int {
+	max := 0
+	for _, v := range c.chars {
+		for k, _ := range v {
+			if k > max {
+				max = k
+			}
+		}
+	}
+	return max * 2
+}
+
+func (c Canvas) MinX() int {
+	min := 0
+	for _, v := range c.chars {
+		for k, _ := range v {
+			if k < min {
+				min = k
+			}
+		}
+	}
+	return min * 2
+}
+
+// Clear all pixels
+func (c *Canvas) Clear() {
+	c.chars = make(map[int]map[int]int)
+}
+
+// Convert x,y to cols, rows
+func (c Canvas) get_pos(x, y int) (int, int) {
+	return (x / 2), (y / 4)
+}
+
+// Set a pixel of c
+func (c *Canvas) Set(x, y int) {
+	px, py := c.get_pos(x, y)
+	if m := c.chars[py]; m == nil {
+		c.chars[py] = make(map[int]int)
+	}
+	val := c.chars[py][px]
+	mapv := getPixel(y, x)
+	c.chars[py][px] = val | mapv
+}
+
+// Unset a pixel of c
+func (c *Canvas) UnSet(x, y int) {
+	px, py := c.get_pos(x, y)
+	x, y = int(math.Abs(float64(x))), int(math.Abs(float64(y)))
+	if m := c.chars[py]; m == nil {
+		c.chars[py] = make(map[int]int)
+	}
+	c.chars[py][px] = c.chars[py][px] &^ getPixel(y, x)
+}
+
+// Toggle a point
+func (c *Canvas) Toggle(x, y int) {
+	px, py := c.get_pos(x, y)
+	if (c.chars[py][px] & getPixel(y, x)) != 0 {
+		c.UnSet(x, y)
+	} else {
+		c.Set(x, y)
+	}
+}
+
+// Set text to the given coordinates
+func (c *Canvas) SetText(x, y int, text string) {
+	x, y = x/2, y/4
+	if m := c.chars[y]; m == nil {
+		c.chars[y] = make(map[int]int)
+	}
+	for i, char := range text {
+		c.chars[y][x+i] = int(char) - braille_char_offset
+	}
+}
+
+// Get pixel at the given coordinates
+func (c Canvas) Get(x, y int) bool {
+	dot_index := pixel_map[y%4][x%2]
+	x, y = x/2, y/4
+	char := c.chars[y][x]
+	return (char & dot_index) != 0
+}
+
+// GetScreenCharacter gets character at the given screen coordinates
+func (c Canvas) GetScreenCharacter(x, y int) rune {
+	return rune(c.chars[y][x] + braille_char_offset)
+}
+
+// GetCharacter gets character for the given pixel
+func (c Canvas) GetCharacter(x, y int) rune {
+	return c.GetScreenCharacter(x/4, y/4)
+}
+
+// Rows retrieves the rows from a given view
+func (c Canvas) Rows(minX, minY, maxX, maxY int) []string {
+	minrow, maxrow := minY/4, (maxY)/4
+	mincol, maxcol := minX/2, (maxX)/2
+
+	ret := make([]string, 0)
+	for rownum := minrow; rownum < (maxrow + 1); rownum = rownum + 1 {
+		row := ""
+		for x := mincol; x < (maxcol + 1); x = x + 1 {
+			char := c.chars[rownum][x]
+			row += string(rune(char + braille_char_offset))
+		}
+		ret = append(ret, row)
+	}
+	return ret
+}
+
+// Frame retrieves a string representation of the frame at the given parameters
+func (c Canvas) Frame(minX, minY, maxX, maxY int) string {
+	var ret string
+	for _, row := range c.Rows(minX, minY, maxX, maxY) {
+		ret += row
+		ret += c.LineEnding
+	}
+	return ret
+}
+
+func (c Canvas) String() string {
+	return c.Frame(c.MinX(), c.MinY(), c.MaxX(), c.MaxY())
+}
+
+type Point struct {
+	X, Y int
+}
+
+// Line returns []Point where each Point is a dot in the line
+func Line(x1, y1, x2, y2 int) []Point {
+	xdiff := abs(x1 - x2)
+	ydiff := abs(y2 - y1)
+
+	var xdir, ydir int
+	if x1 <= x2 {
+		xdir = 1
+	} else {
+		xdir = -1
+	}
+	if y1 <= y2 {
+		ydir = 1
+	} else {
+		ydir = -1
+	}
+
+	r := max(xdiff, ydiff)
+
+	points := make([]Point, r+1)
+
+	for i := 0; i <= r; i++ {
+		x, y := x1, y1
+		if ydiff != 0 {
+			y += (i * ydiff) / (r * ydir)
+		}
+		if xdiff != 0 {
+			x += (i * xdiff) / (r * xdir)
+		}
+		points[i] = Point{x, y}
+	}
+
+	return points
+}
+
+// DrawLine draws a line onto the Canvas
+func (c *Canvas) DrawLine(x1, y1, x2, y2 int) {
+	for _, p := range Line(x1, y1, x2, y2) {
+		c.Set(p.X, p.Y)
+	}
+}
+
+func (c *Canvas) DrawPolygon(center_x, center_y, sides, radius float64) {
+	degree := 360 / sides
+	for n := 0; n < int(sides); n = n + 1 {
+		a := float64(n) * degree
+		b := float64(n+1) * degree
+
+		x1 := int(center_x + (math.Cos(radians(a)) * (radius/2 + 1)))
+		y1 := int(center_y + (math.Sin(radians(a)) * (radius/2 + 1)))
+		x2 := int(center_x + (math.Cos(radians(b)) * (radius/2 + 1)))
+		y2 := int(center_y + (math.Sin(radians(b)) * (radius/2 + 1)))
+
+		c.DrawLine(x1, y1, x2, y2)
+	}
+}
+
+func radians(d float64) float64 {
+	return d * (math.Pi / 180)
+}
+
+func round(x float64) int {
+	return int(x + 0.5)
+}
+
+func min(x, y int) int {
+	if x < y {
+		return x
+	}
+	return y
+}
+
+func max(x, y int) int {
+	if x > y {
+		return x
+	}
+	return y
+}
+
+func abs(x int) int {
+	if x < 0 {
+		return x * -1
+	}
+	return x
+}