Imagination PowerVR SDK Blog

Vertex texture fetch on SGX 535?

pvrvframe

#1

Greetings!





Just curious if anyone knows whether VTF is supported on SGX devices (independent of whether not the drivers supplied for specific phones/etc. using the GPU expose it in their OpenGL ES 2.0 implementation).





Many thanks!



#2

Yes, SGX supports vertex texture fetch.


#3

Hello Georg (and company)

 

I cannot get the VTF to work on my system. My configuration is as follows:

 

    ATI Radeon 9600 / X1050 Series

    Windows XP (32-bit with SP 3)

    OGLES_WINDOWS_PCEMULATION_2.04.24.0811

 

The query for GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS  returns 0


 

My vertex shader code is:

 

    attribute vec3 inPosition;
    attribute vec2 inTexCoord;

 

    uniform mat4 mvpMatrix;
    uniform highp sampler2D heightMap;

 

    varying highp vec4 varWorldPos;
    varying highp vec2 varTexCoords;

    void main()
    {
        highp float height = texture2D( heightMap, inTexCoord ).x;

        highp vec4 newPos = vec4( inPosition, 1.0 );
        newPos.y = height * 128.0;

        varTexCoords = inTexCoord;
        varWorldPos = newPos;

        gl_Position = mvpMatrix * newPos;
    }

 

And the fragment:

 

    varying highp vec4 varWorldPos;
    varying highp vec2 varTexCoords;


    uniform highp sampler2D heightMap;

 

    void main()
    {
        highp vec4 color = texture2D( heightMap, varTexCoords );
        highp float h = varWorldPos.y / 128.0;
        gl_FragColor = vec4( color.r, color.g, color.b, h );
    }

 

I tried updating the drivers but nothing seemed to help. Do you have any recommendations?

 

Thanks,

 

Jerry

 

#4

BTW, glGetString reports “OpenGL ES 2.0 (SDK build: 2.04.24.0809)”

 

This is different from the directory version name.

#5

Hi,

Please download newer version of our SDK from Insider SDK (https://www.imgtec.com/powervr/insider/powervr-sdk.asp) and download most recent PVRVFrame(pcemulation) from Insider Utilities (https://www.imgtec.com/powervr/insider/powervr-vframe.asp). Let us now if this solves your problem.

Regards,




#6

Thanks for link Jacek.


Unfortunately that did not resolve my problem. I think the problem is that the card is an '02 model. From my understanding this card supports vertex shader 2.

 

#7

If your card only supports shader model 2 then vertex shader fetches aren’t going to work on your system at all, never mind under PVRVFrame. The emulation is limited by the capabilities of your graphics hardware. Your only option is to upgrade the card.


#8

Yes, and when the IT department gave me my new machine ~ 3 months ago they said it had a high performance graphics card in it. . .lol

 

From what little research I did on Google, I was left with the impression that the GPU core is dated to 2002 :D

#9

BTW, the project works on my home machine. . .