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Re: [Public WebGL] OpenGL ES 3.0 announced




On 2012-08-06, at 7:45 PM, Gregg Tavares (社用) wrote:

Here's my 10 minute scan of new features in 3.0 vs 2.0

TransformFeedback (output from vertex shader to buffer)
Mapping Buffers to memory
Pixel Buffers, Copying Buffers.
Uniform Blocks (mapping uniforms to buffers)
Vertex Array Objects
Occlusion Queries
Lots more texture formats (floating point, integer, etc..)
Flat Shading
3D textures
Textures: NPOT, Min LOD, Max LOD, Compare Mode 
Samplers (samplers are separate from textures, not sure of the implications since the same settings are available on both) 

The sampler parameters take precedence over those from the textures. (This is the same as in Desktop GL.)

Multiple Render Targets
Multi-Sampling
Sync/Fence
ETC2 texture compression

min MAX_TEXTURE_IMAGE_UNITS        =  16 (was   8)
min MAX_VERTEX_UNIFORM_VECTORS     = 256 (was 128)
min MAX_FRAGMENT_UNIFORM_VECTORS   = 224 (was  16)
min MAX_VERTEX_TEXTURE_IMAGE_UNITS =  16 (was   0)
min MAX_VARYING_VECTORS            =  15 (was   8)
min MAX_DRAW_BUFFERS               =   4 (was   0)

The ETC2 thing is both great and sad. Great that someday ETC2 will be everywhere. Sad that there is no ETC2 on desktop so I'm not sure what's supposed to happen there. Expand to uncompressed?
But there is -- GL 4.3 (which was also released today BTW!) includes support for ES3 compatibility and brings ETC2/EAC to the desktop (Of course the driver may just be uncompressing them for you though.)

And this gotcha from the ES 3.0 spec:

"When using array or matrix variables in a shader, it is possible to access a variable with an index computed at run time that is outside the declared extent of the
variable. Such out-of-bounds accesses have undefined behavior, and system errors (possibly including program termination) may occur. The level of protection
provided against such errors in the shader is implementation-dependent"

Yea!! :-(


On Mon, Aug 6, 2012 at 3:17 PM, Florian Bösch <pyalot@gmail.com> wrote:
On Tue, Aug 7, 2012 at 12:12 AM, Ashley Gullen <ashley@scirra.com> wrote:
Are there any plans for a WebGL spec based on the updated OpenGL ES 3.0?
Also can we start introducing extensions to bridge the expected gap to WebGL 2.0 based on OpenGL ES 3.0 such as multi render targets and draw instanced?