Prepare a PNG snapshot

Inspect the browser contract

PNG lowers the retained Graphic to SVG and then asks its host for a rasterizer. The browser can load and inspect this contract, but it does not pretend to spawn rsvg-convert or ImageMagick. Calling .png.Render here therefore reports png-rasterizer-unavailable.

Runnable RiXRun cell

.Plugin.Load("png"); scene := .Graphics.Graphic([180, 100], [ .Graphics.Circle([90, 50], 32, {= fill="#0c7b7f" }) ]); [.Renderer.Info("png").Get("mime"), scene];

Use .png.Render(scene, {= scale=2, dpi=144, background="white" }) in a capable host, or .Out("diagram.png", scene) with the CLI.

• Browser: contract discovery and portable input preview only.
• CLI: requires rsvg-convert or ImageMagick's magick.
• Size options: scale, dpi, width, and height.
• Color options: background, colorProfile="srgb"|"native"|"none", and

antialiasing="on"|"off".

• Asset options: a scalar metadata map, region=[x,y,width,height], and a

document figure index or label.

Prepare a reproducible asset policy

This cell is browser-safe because it constructs and displays the policy rather than attempting host process execution:

Runnable RiXRun cell

scene := .Graphics.Graphic([180, 100], [ .Graphics.Circle([90, 50], 32, {= fill="#0c7b7f" }) ]); policy := {= dpi=300, background="white", colorProfile="srgb", antialiasing="on", metadata={= Title="Circle construction",Author="RiX" }, region=[40,10,100,80] }; [scene,policy];

At 300 DPI with the default scale, that 100-by-80 logical region becomes 313-by-250 pixels after outward-independent nearest integer sizing. Supplying only width or only height preserves the crop's aspect ratio.

Select a Figure from a document

Runnable RiXRun cell

scene := .Graphics.Graphic([180, 100], [ .Graphics.Circle([90, 50], 32, {= fill="#0c7b7f" }) ]); report := .Fragment([ .Figure(scene,"Whole scene","whole","A teal circle"), .Figure(.Graphics.Graphic([80,60],[ .Graphics.Circle([40,30],20,{= fill="#be123c" }) ]),"Detail","detail","A red detail circle") ]); [report,"""CLI: .png.Render(report,{= figure="detail",dpi=144 })"""];

A capable host can rasterize either Figure without flattening the whole document. The PNG result retains the selected label, caption, alternative text, source dimensions, and normalized byte policy.

The repository's polynomial-transparency.rix fixture overlays a half-opacity annotation on a quadratic curve. Host tests render that same SVG through librsvg and ImageMagick and compare the visible result with a tolerant metric, so toolchain upgrades need not preserve incidental PNG bytes.