Size Units and Conversion

When you set font sizes, line widths, or exported image dimensions through the Dino-GSP Open Platform, the relevant parameters generally use px. If your design file, typesetting software, or print specification uses pt, convert those values to px before passing them to Dino-GSP.

Quick answer

• Setting font size, line width, or the displayed size of a point or marker: use px.
• Specifying the width and height of an exported raster image: use px.
• Working from a typesetting or print value in pt: convert it to px before filling the parameter.
• Setting geometry coordinates, geometric lengths, or view bounds: use logical canvas coordinates and do not perform px/pt conversion.

Use px for visual dimensions

When you control the displayed size of text, lines, or other canvas elements, use px (pixels), including:

• font sizes;
• line widths and borders;
• the visual size of points, markers, and similar objects;
• the pixel width and height of exported raster images.

In SDK, API, MCP, and project-file data, these fields normally accept numbers. If a font-size field has the value 16, read it as 16 px, not 16 pt. Unless the relevant interface documentation says otherwise, pass the number 16 rather than a string such as "16px" or "12pt".

Not every number is a px value

If you are setting geometric point coordinates, geometric lengths, or canvas view bounds, those values use logical canvas coordinates rather than px and do not need pt conversion. Before filling a parameter, check its interface documentation to determine whether it represents a visual size, output pixels, or logical coordinates.

Where you need to pay attention to units

When you use	You may need to set	What to do
Embedded canvas and editor	Font size, line width, and the displayed size of points and markers	Enter px values for visual styles; control iframe dimensions with your host page's CSS
SDK and project-file protocol	Visual style dimensions of canvas objects	Enter px values for style dimensions; use logical coordinates for point positions and geometric lengths
API rendering and image export	Output image dimensions, font sizes, and line widths inside the image	Fixed output and returned image dimensions use px; view parameters such as viewBound use logical coordinates
MCP, REPL, and AI drawing	Font sizes, line widths, and related styles set through instructions or tools	Use px for style dimensions and logical coordinates for mathematical coordinates and lengths
Typesetting and print	Font sizes, line widths, and final physical dimensions	Convert pt to px before filling Dino-GSP parameters; account for DPI separately for raster output

Understanding px

px is the pixel unit commonly used by web pages and canvases. You can use it to express a visual size on screen or the output dimensions of a raster image.

However, 1 px is not necessarily one physical display pixel and does not inherently represent a fixed length on paper. Device pixel ratio, browser zoom, canvas camera zoom, and export settings can all affect the final displayed or output size.

• For font sizes and line widths, px describes the standard visual size.
• For raster-output width and height, px describes the actual number of image pixels.
• For geometry coordinates and view bounds, values are not px; rendering maps them to pixels according to the canvas scale.

Understanding and handling pt

pt (point) is an absolute unit commonly used in typesetting and print, where 1 pt = 1/72 in. Dino-GSP size parameters do not use pt directly. When your design or typesetting specification provides pt values, convert them using the CSS absolute-unit ratio:

96 px = 72 pt = 1 in

pt = px × 0.75
px = pt × 96 ÷ 72 = pt × 4 ÷ 3

For example, a 12 pt print font converts to 16 px, so the Dino-GSP font-size parameter should contain the numeric value 16.

Converter

Dino-GSP parameter (px)=Typesetting or print size (pt)

Edit either value to update the other automatically. Results use up to three decimal places.

Filling integration parameters

When you fill a font size, line width, or other visual dimension in SDK, API, or MCP data, convert any pt value you have to px first. The following is illustrative; use the field names documented for the interface you are calling:

{
  "fontSize": 16,
  "strokeWidth": 0.667
}

These values correspond to a 12 pt font size and a 0.5 pt line width.

Precision and print considerations

• Keep 2–3 decimal places in protocol values. Do not round fine line widths to integers too early, as this can introduce substantial error.
• The px/pt conversion aligns the meaning of dimension parameters. Final physical size may still be affected by scaling during export, placement, or printing.
• Raster printing also depends on DPI. For a specified physical size, use pixels = pt ÷ 72 × DPI. This sampling calculation is separate from the protocol's px/pt size conversion.
• After placing an export in typesetting software, check for automatic scaling and proof the actual output size before production printing.