[mapserver-dev] mapgd2 - raster support

[thomas bonfort]

On Wed, Feb 24, 2010 at 18:16, Frank Warmerdam <warmerdam at pobox.com> wrote:
> Steve / Thomas,
>
> I've been reasonable successful implementing raster support for plugin
> renderers that implement supports_pixel_buffer / getRasterBuffer().  Now
> I'd like to implement support for renders that don't, and that instead offer
> mergeRasterBuffer().
>
> I assume that the GD2 renderer is intended to work this way right?

mergeRasterBuffer is mainly intended for vector renderers who's
internal structure isn't an array of pixels.
For GD2 we aren't in the same use-case, as we have an array of pixels,
just not in the common format. GD2 would have to implement
mergeRasterBuffer, but *only* for handling layers with opacity != 100,
not for the raster layers. The other renderers also must implement
mergeRasterBuffer for the opacity!=100 case , unless they natively
support the concept of transparent layers (only cairo does at the time
being).
I hope I'm being somewhat clear here, if not tell me.

regards,
thomas