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Re: [Public WebGL] problematic GetParameter pnames



The first three are equivalent respectively to the following in Open GL 3.1:
MAX_FRAGMENT_UNIFORM_COMPONENTS/4
MAX_VERTEX_UNIFORM_COMPONENTS/4
MAX_VARYING_COMPONENTS/4
For the first 2, I'm assuming the WebGL implementation is using only the default uniform block.

A shader compiler is required for WebGL so I think we decided to drop the SHADER_COMPILER query.

Since readPixels is supported, IMPLEMENTATION_COLOR_READ_FORMAT and IMPLEMENTATION_COLOR_READ_TYPE ought to be supported by WebGL so the application can use the most efficient format when reading pixels. This seems be an oversight in the WebGL spec. There is no equivalent on desktop GL as typically they have format conversion hardware so any format is equally good. A WebGL implementation on desktop will have to emulate these.

Regards

-Mark





On 10/06/2010 06:38, Benoit Jacob wrote:
Hi,

I have trouble implementing the following pnames in GetParameter:

A. The following pnames are mentioned in the WebGl spec for GetParameter, but are seem to be absent from desktop OpenGL. How to implement them on desktop OpenGL systems?
    MAX_FRAGMENT_UNIFORM_VECTORS
    MAX_VERTEX_UNIFORM_VECTORS
    MAX_VARYING_VECTORS

B. The following pnames are mentioned in the WebGL spec only in the general list of constants, but not in the section on getParameter. Yet the gl-get-calls test is trying to pass them to getParameter. Which is right?
    SHADER_COMPILER
    IMPLEMENTATION_COLOR_READ_FORMAT
    IMPLEMENTATION_COLOR_READ_TYPE

Cheers,
Benoit
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