Did a lot of work off-repo, basically init

ui/drawfunctions.go

@@ -0,0 +1,51 @@
+package ui
+
+import "github.com/gdamore/tcell/v2"
+
+// DrawRect renders a filled box at `x` and `y`, of size `width` and `height`.
+// Will not call `Show()`.
+func DrawRect(s tcell.Screen, x, y, width, height int, char rune, style tcell.Style) {
+	for col := x; col < x+width; col++ {
+		for row := y; row < y+height; row++ {
+			s.SetContent(col, row, char, nil, style)
+		}
+	}
+}
+
+// DrawStr will render each character of a string at `x` and `y`.
+func DrawStr(s tcell.Screen, x, y int, str string, style tcell.Style) {
+	runes := []rune(str)
+	for idx := 0; idx < len(runes); idx++ {
+		s.SetContent(x+idx, y, runes[idx], nil, style)
+	}
+}
+
+// DrawRectOutline draws only the outline of a rectangle, using `ul`, `ur`, `bl`, and `br`
+// for the corner runes, and `hor` and `vert` for the horizontal and vertical runes, respectively.
+func DrawRectOutline(s tcell.Screen, x, y, _width, _height int, ul, ur, bl, br, hor, vert rune, style tcell.Style) {
+	width := x + _width - 1   // Length across
+	height := y + _height - 1 // Length top-to-bottom
+
+	// Horizontals and verticals
+	for col := x + 1; col < width; col++ {
+		s.SetContent(col, y, hor, nil, style)      // Top line
+		s.SetContent(col, height, hor, nil, style) // Bottom line
+	}
+	for row := y + 1; row < height; row++ {
+		s.SetContent(x, row, vert, nil, style)     // Left line
+		s.SetContent(width, row, vert, nil, style) // Right line
+	}
+	// Corners
+	s.SetContent(x, y, ul, nil, style)
+	s.SetContent(width, y, ur, nil, style)
+	s.SetContent(x, height, bl, nil, style)
+	s.SetContent(width, height, br, nil, style)
+}
+
+// DrawRectOutlineDefault calls DrawRectOutline with the default edge runes.
+func DrawRectOutlineDefault(s tcell.Screen, x, y, width, height int, style tcell.Style) {
+	DrawRectOutline(s, x, y, width, height, '┌', '┐', '└', '┘', '─', '│', style)
+}
+
+// TODO: add DrawShadow(x, y, width, height int)
+// TODO: add DrawWindow(x, y, width, height int, style tcell.Style)