Choosing a renderer

The cell renderer works everywhere. The shader renderer is faster on large surfaces. Which devices have it and what it can draw.

Modifier.dither, Modifier.ditherFill, Modifier.ditherMask and the DitherText and DitherImage components take a renderer:

Both draw the same picture. In the tests, the shader output matches the cell output for every built-in field and Bayer size to within a handful of pixels in 40,000. The noise field matches exactly, because the cell renderer and the shader use the same float hash.

What the shader can draw

The shader renderer draws an element only if all of these hold. Otherwise the cell renderer draws it, with no error:

• the field is a ShaderField, which all the built-in fields except ditherProgress’s progress field are: solid, linear, radial, noise, waves, ripples and sweep;
• the pattern is Bayer 2, 4 or 8, or any pattern up to 256 cells wide, blue noise included (the shader reads it from a texture);
• the theme has two to eight colours, so a palette of up to eight works; cells can be squares or dots;
• the platform has runtime shaders, and the platform’s compiler accepts the program.

For ditherFill and ditherMask the shader draws inside the offscreen layer those modifiers already use, so the content keeps its shape and transparency. The sweep’s progress reaches the shader as a uniform, so an animated reveal compiles one program.

Where it runs

Firefox has not been checked, and neither has Safari itself.