May 19

https://code.dlang.org/packages/turtle

"The turtle package provides a friendly, software-rendered, and hi-DPI drawing solution, for when all you want is a Canvas API. It depends on SDL for windowing."

(In reality in this early version it's only fit for really simple data visualization programs. Expect the API to change a lot and support to be inexistent.)

Example:

import turtle;

int main(string[] args)
{
    runGame(new CanvasExample);
    return 0;
}

class CanvasExample : TurtleGame
{
    override void load()
    {
        setBackgroundColor( color("#6A0035") );
    }

    override void update(double dt)
    {
        if (keyboard.isDown("escape")) exitGame;
    }

    override void draw()
    {
        foreach(layer; 0..8)
            with(canvas)
            {
                save();

                translate(windowWidth / 2, windowHeight / 2);
                float zoom = windowHeight/4 * (1.0 - layer / 7.0) ^^ (1.0 + 0.2 * cos(elapsedTime));
                scale(zoom, zoom);
                rotate(layer + elapsedTime * (0.5 + layer * 0.1));

                auto gradient = createCircularGradient(0, 0, 3);

                int r = 255 - layer * 32;
                int g = 64 + layer * 16;
                int b = 128;
                gradient.addColorStop(0, color(r, g, b, 255));
                gradient.addColorStop(1, color(r/2, g/3, b/2, 255));

                fillStyle = gradient;

                beginPath();
                    moveTo(-1, -1);
                    lineTo( 0, -3);
                    lineTo(+1, -1);
                    lineTo(+3,  0);
                    lineTo(+1, +1);
                    lineTo( 0, +3);
                    lineTo(-1, +1);
                    lineTo(-3,  0);
                closePath();
                fill();

                restore();
            }
    }
}

It builds upon dplug:graphcis, itself a dg2d fork, which is a high-speed simple rasterizer without stroke().

May 21
On Wednesday, 19 May 2021 at 16:41:54 UTC, Guillaume Piolat wrote:
> https://code.dlang.org/packages/turtle
>
> "The turtle package provides a friendly, software-rendered, and hi-DPI drawing solution, for when all you want is a Canvas API. It depends on SDL for windowing."
>
> [...]

dplug:canvas, dplug:graphcis is interesting.

>                 fillStyle = gradient;

>                 beginPath();
>                     moveTo(-1, -1);
>                     lineTo( 0, -3);
>                     lineTo(+1, -1);
>                     lineTo(+3,  0);
>                     lineTo(+1, +1);
>                     lineTo( 0, +3);
>                     lineTo(-1, +1);
>                     lineTo(-3,  0);
>                 closePath();
>                 fill();
Looks readable.