- name: 2d.transformation.order
  desc: Transformations are applied in the right order
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.scale(2, 1);
    ctx.rotate(Math.PI / 2);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, -50, 50, 50);
    @assert pixel 75,25 == 0,255,0,255;
  expected: green


- name: 2d.transformation.scale.basic
  desc: scale() works
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.scale(2, 4);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, 0, 50, 12.5);
    @assert pixel 90,40 == 0,255,0,255;
  expected: green

- name: 2d.transformation.scale.zero
  desc: scale() with a scale factor of zero works
  code: |
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, 0, 100, 50);

    ctx.save();
    ctx.translate(50, 0);
    ctx.scale(0, 1);
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);
    ctx.restore();

    ctx.save();
    ctx.translate(0, 25);
    ctx.scale(1, 0);
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);
    ctx.restore();

    @assert pixel 50,25 == 0,255,0,255;
  expected: green

- name: 2d.transformation.scale.negative
  desc: scale() with negative scale factors works
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.save();
    ctx.scale(-1, 1);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(-50, 0, 50, 50);
    ctx.restore();

    ctx.save();
    ctx.scale(1, -1);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(50, -50, 50, 50);
    ctx.restore();
    @assert pixel 25,25 == 0,255,0,255;
    @assert pixel 75,25 == 0,255,0,255;
  expected: green

- name: 2d.transformation.scale.large
  desc: scale() with large scale factors works
  notes: Not really that large at all, but it hits the limits in Firefox.
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.scale(1e5, 1e5);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, 0, 1, 1);
    @assert pixel 50,25 == 0,255,0,255;
  expected: green

- name: 2d.transformation.scale.nonfinite
  desc: scale() with Infinity/NaN is ignored
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.translate(100, 10);
    @nonfinite ctx.scale(<0.1 Infinity -Infinity NaN>, <0.1 Infinity -Infinity NaN>);

    ctx.fillStyle = '#0f0';
    ctx.fillRect(-100, -10, 100, 50);

    @assert pixel 50,25 == 0,255,0,255;
  expected: green

- name: 2d.transformation.scale.multiple
  desc: Multiple scale()s combine
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.scale(Math.sqrt(2), Math.sqrt(2));
    ctx.scale(Math.sqrt(2), Math.sqrt(2));
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, 0, 50, 25);
    @assert pixel 90,40 == 0,255,0,255;
  expected: green


- name: 2d.transformation.rotate.zero
  desc: rotate() by 0 does nothing
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.rotate(0);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, 0, 100, 50);
    @assert pixel 50,25 == 0,255,0,255;
  expected: green

- name: 2d.transformation.rotate.radians
  desc: rotate() uses radians
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.rotate(Math.PI); // should fail obviously if this is 3.1 degrees
    ctx.fillStyle = '#0f0';
    ctx.fillRect(-100, -50, 100, 50);
    @assert pixel 50,25 == 0,255,0,255;
  expected: green

- name: 2d.transformation.rotate.direction
  desc: rotate() is clockwise
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.rotate(Math.PI / 2);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, -100, 50, 100);
    @assert pixel 50,25 == 0,255,0,255;
  expected: green

- name: 2d.transformation.rotate.wrap
  desc: rotate() wraps large positive values correctly
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.rotate(Math.PI * (1 + 4096)); // == pi (mod 2*pi)
    // We need about pi +/- 0.001 in order to get correct-looking results
    // 32-bit floats can store pi*4097 with precision 2^-10, so that should
    // be safe enough on reasonable implementations
    ctx.fillStyle = '#0f0';
    ctx.fillRect(-100, -50, 100, 50);
    @assert pixel 50,25 == 0,255,0,255;
    @assert pixel 98,2 == 0,255,0,255;
    @assert pixel 98,47 == 0,255,0,255;
  expected: green

- name: 2d.transformation.rotate.wrapnegative
  desc: rotate() wraps large negative values correctly
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.rotate(-Math.PI * (1 + 4096));
    ctx.fillStyle = '#0f0';
    ctx.fillRect(-100, -50, 100, 50);
    @assert pixel 50,25 == 0,255,0,255;
    @assert pixel 98,2 == 0,255,0,255;
    @assert pixel 98,47 == 0,255,0,255;
  expected: green

- name: 2d.transformation.rotate.nonfinite
  desc: rotate() with Infinity/NaN is ignored
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.translate(100, 10);
    @nonfinite ctx.rotate(<0.1 Infinity -Infinity NaN>);

    ctx.fillStyle = '#0f0';
    ctx.fillRect(-100, -10, 100, 50);

    @assert pixel 50,25 == 0,255,0,255;
  expected: green

- name: 2d.transformation.translate.basic
  desc: translate() works
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.translate(100, 50);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(-100, -50, 100, 50);
    @assert pixel 90,40 == 0,255,0,255;
  expected: green

- name: 2d.transformation.translate.nonfinite
  desc: translate() with Infinity/NaN is ignored
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.translate(100, 10);
    @nonfinite ctx.translate(<0.1 Infinity -Infinity NaN>, <0.1 Infinity -Infinity NaN>);

    ctx.fillStyle = '#0f0';
    ctx.fillRect(-100, -10, 100, 50);

    @assert pixel 50,25 == 0,255,0,255;
  expected: green


- name: 2d.transformation.transform.identity
  desc: transform() with the identity matrix does nothing
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.transform(1,0, 0,1, 0,0);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, 0, 100, 50);
    @assert pixel 50,25 == 0,255,0,255;
  expected: green

- name: 2d.transformation.transform.skewed
  desc: transform() with skewy matrix transforms correctly
  code: |
    // Create green with a red square ring inside it
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, 0, 100, 50);
    ctx.fillStyle = '#f00';
    ctx.fillRect(20, 10, 60, 30);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(40, 20, 20, 10);

    // Draw a skewed shape to fill that gap, to make sure it is aligned correctly
    ctx.transform(1,4, 2,3, 5,6);
    // Post-transform coordinates:
    //   [[20,10],[80,10],[80,40],[20,40],[20,10],[40,20],[40,30],[60,30],[60,20],[40,20],[20,10]];
    // Hence pre-transform coordinates:
    var pts=[[-7.4,11.2],[-43.4,59.2],[-31.4,53.2],[4.6,5.2],[-7.4,11.2],
             [-15.4,25.2],[-11.4,23.2],[-23.4,39.2],[-27.4,41.2],[-15.4,25.2],
             [-7.4,11.2]];
    ctx.beginPath();
    ctx.moveTo(pts[0][0], pts[0][1]);
    for (var i = 0; i < pts.length; ++i)
        ctx.lineTo(pts[i][0], pts[i][1]);
    ctx.fill();
    @assert pixel 21,11 == 0,255,0,255;
    @assert pixel 79,11 == 0,255,0,255;
    @assert pixel 21,39 == 0,255,0,255;
    @assert pixel 79,39 == 0,255,0,255;
    @assert pixel 39,19 == 0,255,0,255;
    @assert pixel 61,19 == 0,255,0,255;
    @assert pixel 39,31 == 0,255,0,255;
    @assert pixel 61,31 == 0,255,0,255;
  expected: green

- name: 2d.transformation.transform.multiply
  desc: transform() multiplies the CTM
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.transform(1,2, 3,4, 5,6);
    ctx.transform(-2,1, 3/2,-1/2, 1,-2);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, 0, 100, 50);
    @assert pixel 50,25 == 0,255,0,255;
  expected: green

- name: 2d.transformation.transform.nonfinite
  desc: transform() with Infinity/NaN is ignored
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.translate(100, 10);
    @nonfinite ctx.transform(<0 Infinity -Infinity NaN>, <0 Infinity -Infinity NaN>, <0 Infinity -Infinity NaN>, <0 Infinity -Infinity NaN>, <0 Infinity -Infinity NaN>, <0 Infinity -Infinity NaN>);

    ctx.fillStyle = '#0f0';
    ctx.fillRect(-100, -10, 100, 50);

    @assert pixel 50,25 == 0,255,0,255;
  expected: green

- name: 2d.transformation.setTransform.skewed
  code: |
    // Create green with a red square ring inside it
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, 0, 100, 50);
    ctx.fillStyle = '#f00';
    ctx.fillRect(20, 10, 60, 30);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(40, 20, 20, 10);

    // Draw a skewed shape to fill that gap, to make sure it is aligned correctly
    ctx.setTransform(1,4, 2,3, 5,6);
    // Post-transform coordinates:
    //   [[20,10],[80,10],[80,40],[20,40],[20,10],[40,20],[40,30],[60,30],[60,20],[40,20],[20,10]];
    // Hence pre-transform coordinates:
    var pts=[[-7.4,11.2],[-43.4,59.2],[-31.4,53.2],[4.6,5.2],[-7.4,11.2],
             [-15.4,25.2],[-11.4,23.2],[-23.4,39.2],[-27.4,41.2],[-15.4,25.2],
             [-7.4,11.2]];
    ctx.beginPath();
    ctx.moveTo(pts[0][0], pts[0][1]);
    for (var i = 0; i < pts.length; ++i)
        ctx.lineTo(pts[i][0], pts[i][1]);
    ctx.fill();
    @assert pixel 21,11 == 0,255,0,255;
    @assert pixel 79,11 == 0,255,0,255;
    @assert pixel 21,39 == 0,255,0,255;
    @assert pixel 79,39 == 0,255,0,255;
    @assert pixel 39,19 == 0,255,0,255;
    @assert pixel 61,19 == 0,255,0,255;
    @assert pixel 39,31 == 0,255,0,255;
    @assert pixel 61,31 == 0,255,0,255;
  expected: green

- name: 2d.transformation.setTransform.multiple
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.setTransform(1/2,0, 0,1/2, 0,0);
    ctx.setTransform();
    ctx.setTransform(2,0, 0,2, 0,0);
    ctx.fillStyle = '#0f0';
    ctx.fillRect(0, 0, 50, 25);
    @assert pixel 75,35 == 0,255,0,255;
  expected: green

- name: 2d.transformation.setTransform.nonfinite
  desc: setTransform() with Infinity/NaN is ignored
  code: |
    ctx.fillStyle = '#f00';
    ctx.fillRect(0, 0, 100, 50);

    ctx.translate(100, 10);
    @nonfinite ctx.setTransform(<0 Infinity -Infinity NaN>, <0 Infinity -Infinity NaN>, <0 Infinity -Infinity NaN>, <0 Infinity -Infinity NaN>, <0 Infinity -Infinity NaN>, <0 Infinity -Infinity NaN>);

    ctx.fillStyle = '#0f0';
    ctx.fillRect(-100, -10, 100, 50);

    @assert pixel 50,25 == 0,255,0,255;
  expected: green