Thank you a lot, also i have an answer from arm mali ------------------------------------------------------------------------------------------------------ The specification says that some number of texture units are available to vertex shaders. There is a query to get the number of vertex shader texture units which may be used.
>From the spec, v2.0.25, pp40; "Vertex shaders have the ability to do a lookup into a texture map, if supported by the GL implementation. The maximum number of texture image units available to a vertex shader is MAX_VERTEX_TEXTURE_IMAGE_UNITS; a maximum number of zero indicates that the GL implemenation [sic] does not support texture accesses in vertex shaders. The maximum number of texture image units available to the fragment stage of the GL is MAX_TEXTURE_IMAGE_UNITS. Both the vertex shader and fragment processing combined cannot use more than MAX_COMBINED_TEXTURE_- IMAGE_UNITS texture image units." If you query MAX_VERTEX_TEXTURE_IMAGE_UNITS, you will see that Mali targets return zero indicating texture units are not available for vertex shader programs. At a hardware level, this is because the vertex programs are run on a different part of the GPU core from the fragment shaders. The fragment shaders have access to 2D texture fetch units, but the vertex shader does not. This design compromise is common within non-unified GPU cores designed for high performance/low power consumption, including Mali 400 series and also others available in the marketplace (and indeed also on previous generations of desktop OpenGL cards), and GLES hence allows texture units to only optionally be available to vertex shaders indicated by this query. If you could explain a little more about what you're trying to achieve, we may be able to assist you by suggesting an alternate method. Many thanks, ARM MPD Developer Relations -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
