Module Vgr_htmlc

module Vgr_htmlc: sig .. end
Vg HTML canvas renderer.

References.

Release 0.8.2 — Daniel Bünzli <daniel.buenzl i@erratique.ch>



HTML canvas render targets


val screen_resolution : Gg.v2
screen_resolution is the screen resolution in pixels per meters.
val target : ?resize:bool ->
?resolution:Gg.v2 -> Dom_html.canvasElement Js.t -> [ `Other ] Vg.Vgr.target
target resize resolution c is a render target for rendering to the canvas element c.

Multiple images. Multiple images render on the target is supported. Each new render clears the HTML canvas.


Text rendering

Text rendering uses the HTML canvas CSS font selection mechanism. As there is no control over glyph rendering in the HTML canvas, the glyph API is unsupported.

Given a glyph cut:

Vg.I.cut_glyphs ~text ~blocks ~advances font glyphs

The blocks, advances and glyphs parameters are ignored. text must be provided and is used to define the text to render. font is used to select the font in the CSS stylesheet. Make sure that the fonts you use are embedded and loaded in your DOM via @font-face.

At the moment the renderer also needs to work around a particular browser bug which means that glyph cuts are currently limited to non-outline area cuts in I.const images.

Render warnings and limitations

The following render warnings are reported.

The following limitations should be taken into account.