v0.1.0 initial commit

tui/sparkline.go

@@ -0,0 +1,131 @@
+package tui
+
+import "github.com/lixenwraith/terminal"
+
+// SparklineChars provides 8-level vertical resolution
+var SparklineChars = []rune{'▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'}
+
+// SparklineOpts configures sparkline rendering
+type SparklineOpts struct {
+	Min, Max float64 // Range bounds, auto-scale if both 0
+	Style    Style
+}
+
+// Sparkline renders an inline graph of values, values are mapped to 8-level block characters
+func (r Region) Sparkline(x, y, width int, values []float64, opts SparklineOpts) {
+	if y < 0 || y >= r.H || width <= 0 || len(values) == 0 {
+		return
+	}
+
+	// Determine range
+	min, max := opts.Min, opts.Max
+	if min == 0 && max == 0 {
+		min, max = values[0], values[0]
+		for _, v := range values {
+			if v < min {
+				min = v
+			}
+			if v > max {
+				max = v
+			}
+		}
+	}
+
+	// Handle flat line
+	rangeV := max - min
+	if rangeV == 0 {
+		rangeV = 1
+	}
+
+	// Sample or use last N values if more than width
+	var sampled []float64
+	if len(values) <= width {
+		sampled = values
+	} else {
+		sampled = values[len(values)-width:]
+	}
+
+	// Render each value
+	for i, v := range sampled {
+		if x+i >= r.W {
+			break
+		}
+
+		// Normalize to 0-1
+		norm := (v - min) / rangeV
+		if norm < 0 {
+			norm = 0
+		}
+		if norm > 1 {
+			norm = 1
+		}
+
+		// Map to character index (0-7)
+		idx := int(norm * 7.99)
+		if idx > 7 {
+			idx = 7
+		}
+
+		r.Cell(x+i, y, SparklineChars[idx], opts.Style.Fg, opts.Style.Bg, opts.Style.Attr)
+	}
+
+	// Pad remaining width with lowest char if values shorter than width
+	for i := len(sampled); i < width && x+i < r.W; i++ {
+		r.Cell(x+i, y, SparklineChars[0], opts.Style.Fg, opts.Style.Bg, terminal.AttrDim)
+	}
+}
+
+// SparklineV renders vertical sparkline (bottom to top)
+func (r Region) SparklineV(x, y, height int, values []float64, opts SparklineOpts) {
+	if x < 0 || x >= r.W || height <= 0 || len(values) == 0 {
+		return
+	}
+
+	min, max := opts.Min, opts.Max
+	if min == 0 && max == 0 {
+		min, max = values[0], values[0]
+		for _, v := range values {
+			if v < min {
+				min = v
+			}
+			if v > max {
+				max = v
+			}
+		}
+	}
+
+	rangeV := max - min
+	if rangeV == 0 {
+		rangeV = 1
+	}
+
+	var sampled []float64
+	if len(values) <= height {
+		sampled = values
+	} else {
+		sampled = values[len(values)-height:]
+	}
+
+	// Render bottom-up
+	for i, v := range sampled {
+		yPos := y + height - 1 - i
+		if yPos < y || yPos >= r.H {
+			continue
+		}
+
+		norm := (v - min) / rangeV
+		if norm < 0 {
+			norm = 0
+		}
+		if norm > 1 {
+			norm = 1
+		}
+
+		idx := int(norm * 7.99)
+		if idx > 7 {
+			idx = 7
+		}
+
+		r.Cell(x, yPos, SparklineChars[idx], opts.Style.Fg, opts.Style.Bg, opts.Style.Attr)
+	}
+}