canvas_smoke.affine

// SPDX-License-Identifier: MPL-2.0
// bindings #8 — HTML5 Canvas 2D smoke test.
//
// Exercises every shipped extern via a single end-to-end drawing
// sequence: acquire context, set styles, fill rect, stroke path,
// save+translate+rotate+scale+restore the transform, draw text,
// measure text, and drawImage. The harness mocks both the canvas
// element and the 2D context.

use Deno::{Json};
use Canvas::{Ctx2D, canvasGetContext2D, canvasFillStyle, canvasStrokeStyle, canvasLineWidth, canvasGlobalAlpha, canvasFillRect, canvasStrokeRect, canvasClearRect, canvasBeginPath, canvasClosePath, canvasMoveTo, canvasLineTo, canvasArc, canvasFill, canvasStroke, canvasSave, canvasRestore, canvasTranslate, canvasRotate, canvasScale, canvasFont, canvasTextAlign, canvasTextBaseline, canvasFillText, canvasStrokeText, canvasMeasureText, canvasDrawImage, canvasDrawImageScaled};

/// Exercises the styles + rect-drawing surface.
pub fn smokeRects(canvas: Json) -> Ctx2D {
  let ctx = canvasGetContext2D(canvas);
  canvasFillStyle(ctx, "#ff0000");
  canvasStrokeStyle(ctx, "rgba(0, 0, 0, 0.5)");
  canvasLineWidth(ctx, 2.5);
  canvasGlobalAlpha(ctx, 0.75);
  canvasClearRect(ctx, 0.0, 0.0, 100.0, 100.0);
  canvasFillRect(ctx, 10.0, 20.0, 30.0, 40.0);
  canvasStrokeRect(ctx, 50.0, 60.0, 20.0, 20.0);
  ctx
}

/// Exercises the path surface (begin/move/line/arc/close + fill+stroke).
pub fn smokePath(ctx: Ctx2D) -> Int {
  canvasBeginPath(ctx);
  canvasMoveTo(ctx, 10.0, 10.0);
  canvasLineTo(ctx, 20.0, 30.0);
  canvasArc(ctx, 50.0, 50.0, 10.0, 0.0, 6.283);
  canvasClosePath(ctx);
  canvasFill(ctx);
  canvasStroke(ctx);
  0
}

/// Exercises the transform stack — save / translate / rotate / scale /
/// restore — by applying a transform, drawing inside, and popping.
pub fn smokeTransform(ctx: Ctx2D) -> Int {
  canvasSave(ctx);
  canvasTranslate(ctx, 100.0, 100.0);
  canvasRotate(ctx, 1.5708);
  canvasScale(ctx, 2.0, 3.0);
  canvasFillRect(ctx, 0.0, 0.0, 5.0, 5.0);
  canvasRestore(ctx);
  0
}

/// Exercises the text surface — font, align, baseline, fill/stroke
/// text, and measure-text round-trip (returns Json).
pub fn smokeText(ctx: Ctx2D) -> Json {
  canvasFont(ctx, "16px sans-serif");
  canvasTextAlign(ctx, "center");
  canvasTextBaseline(ctx, "middle");
  canvasFillText(ctx, "Hello", 50.0, 50.0);
  canvasStrokeText(ctx, "Outlined", 50.0, 70.0);
  canvasMeasureText(ctx, "Measurement")
}

/// Exercises both drawImage shapes — natural-size and scaled.
pub fn smokeImages(ctx: Ctx2D, img: Json) -> Int {
  canvasDrawImage(ctx, img, 10.0, 20.0);
  canvasDrawImageScaled(ctx, img, 30.0, 40.0, 100.0, 50.0);
  0
}