feat(text-canvas): add bar chart & image fns

packages/text-canvas/src/bars.ts

@@ -0,0 +1,60 @@
+import { fitClamped, fract } from "@thi.ng/math";
+import { padLeft, padRight, repeat } from "@thi.ng/strings";
+import { map } from "@thi.ng/transducers";
+import { BARS_H, BARS_V } from "./api";
+
+export const barChartHStr = (
+    height: number,
+    vals: Iterable<number>,
+    min = 0,
+    max = 1
+) => {
+    const bars = [...map((x) => barVertical(height, x, min, max, ""), vals)];
+    const num = bars.length;
+    const res: string[] = [];
+    for (let i = 0; i < height; i++) {
+        let line = "";
+        for (let j = 0; j < num; j++) {
+            line += bars[j][i];
+        }
+        res.push(line);
+    }
+    return res.join("\n");
+};
+
+export const barChartVStr = (
+    width: number,
+    vals: Iterable<number>,
+    min = 0,
+    max = 1
+) => [...map((x) => barHorizontal(width, x, min, max), vals)].join("\n");
+
+export const barHorizontal = (width: number, x: number, min = 0, max = 1) =>
+    bar(BARS_H, width, false, x, min, max, "");
+
+export const barVertical = (
+    height: number,
+    x: number,
+    min = 0,
+    max = 1,
+    delim = "\n"
+) => bar(BARS_V, height, true, x, min, max, delim);
+
+const bar = (
+    chars: string,
+    size: number,
+    left: boolean,
+    x: number,
+    min: number,
+    max: number,
+    delim: string
+) => {
+    x = fitClamped(x, min, max, 0, size);
+    const f = (fract(x) * 9) | 0;
+    const full = repeat(chars[8] + delim, x | 0);
+    const partial = f > 0 ? chars[f] + delim : "";
+    size += size * delim.length;
+    return left
+        ? padLeft(size, " ")(partial + full)
+        : padRight(size, " ")(full + partial);
+};

packages/text-canvas/src/image.ts

@@ -0,0 +1,36 @@
+import { peek } from "@thi.ng/arrays";
+import { SHADES } from "./api";
+import { Canvas } from "./canvas";
+import { charCode, intersectRect } from "./utils";
+
+// @ts-ignore
+export const image = (
+    canvas: Canvas,
+    x: number,
+    y: number,
+    w: number,
+    h: number,
+    pixels: ArrayLike<number>,
+    format = canvas.format,
+    gamma = 2.2
+) => {
+    x |= 0;
+    y |= 0;
+    const { buf, width } = canvas;
+    const clipRect = peek(canvas.clipRects);
+    const srcRect = { x1: x, y1: y, x2: x + w, y2: y + h, w, h };
+    const { x1, y1, x2, y2, w: iw, h: ih } = intersectRect(srcRect, clipRect);
+    if (!iw || !ih) return;
+    const sx = Math.max(0, x1 - x);
+    const sy = Math.max(0, y1 - y);
+    for (let yy = sy, dy = y1; dy < y2; yy++, dy++) {
+        let sidx = sx + yy * w;
+        let didx = x1 + dy * width;
+        for (let xx = sx, dx = x1; dx < x2; xx++, dx++) {
+            buf[didx++] = charCode(
+                SHADES[(Math.pow(pixels[sidx++] / 255, gamma) * 4) | 0],
+                format
+            );
+        }
+    }
+};

packages/text-canvas/src/index.ts

@@ -1,9 +1,11 @@
 export * from "./api";
 export * from "./ansi";
+export * from "./bars";
 export * from "./canvas";
 export * from "./circle";
 export * from "./html";
 export * from "./hvline";
+export * from "./image";
 export * from "./line";
 export * from "./rect";
 export * from "./string";