Hi all,
I’m getting error reports that the following pixel shader does not compile on Android-driven PowerVR SGX 540 and 530 chipsets. Specifically on the following devices, while it compiles and runs fine on Tegra2, Adreno and all others I have tested it on:
MB525 2.3.7 PowerVR SGX 530 Motorola Defy
SGH-T959 2.2 PowerVR SGX 540 Samsung Vibrant Galaxy S
GT-I9000 2.2 PowerVR SGX 540 Samsung Galaxy S
SGH-T959V 2.2.1 PowerVR SGX 540 Samsung Galaxy S 4G
GT-P1000 2.2 PowerVR SGX 540 Samsung Galaxy Tab P1000
LG-P920 2.2.2 PowerVR SGX 540 LG Optimus 3D
YP-G70 2.2.2 PowerVR SGX 540 Samsung Galaxy S Wifi 5.0
SAMSUNG-SGH-I897 2.2 PowerVR SGX 540 Samsung Captivate
Since I don’t have any of these devices at my disposal, I was hoping someone in these forums could help me out.
Here’s the vertex shader, which compiles fine:
// position and normal of the vertices
attribute vec4 aPosition;
// texture variables
attribute vec2 textureCoord;
varying vec2 tCoord;
uniform float UVscaleX;
uniform float UVscaleY;
void main()
{
tCoord = textureCoord;
gl_Position = aPosition;
}
Here's the pixel shader, which does not compile fine, apparently:
precision mediump float;
varying vec2 tCoord;
uniform vec3 tCoordOffset;
uniform float coordScale;
uniform vec3 octMult;
uniform vec3 colorMult;
uniform sampler2D permTexture;
vec4 permute(vec4 x)
{
return mod(((x*34.0)+1.0)*x, 289.0);
}
vec4 taylorInvSqrt(vec4 r)
{
return 1.79284291400159 - 0.85373472095314 * r;
}
vec3 fade(vec3 t)
{
return t*t*t*(t*(t*6.0-15.0)+10.0);
}
// Classic Perlin noise
float cnoise(vec3 P)
{
vec3 Pi0 = floor(P); // Integer part for indexing
vec3 Pi1 = Pi0 + vec3(1.0); // Integer part + 1
Pi0 = mod(Pi0, 289.0);
Pi1 = mod(Pi1, 289.0);
vec3 Pf0 = fract(P); // Fractional part for interpolation
vec3 Pf1 = Pf0 - vec3(1.0); // Fractional part - 1.0
vec4 ix = vec4(Pi0.x, Pi1.x, Pi0.x, Pi1.x);
vec4 iy = vec4(Pi0.yy, Pi1.yy);
vec4 iz0 = Pi0.zzzz;
vec4 iz1 = Pi1.zzzz;
vec4 ixy = permute(permute(ix) + iy);
vec4 ixy0 = permute(ixy + iz0);
vec4 ixy1 = permute(ixy + iz1);
vec4 gx0 = ixy0 / 7.0;
vec4 gy0 = fract(floor(gx0) / 7.0) - 0.5;
gx0 = fract(gx0);
vec4 gz0 = vec4(0.5) - abs(gx0) - abs(gy0);
vec4 sz0 = step(gz0, vec4(0.0));
gx0 -= sz0 * (step(0.0, gx0) - 0.5);
gy0 -= sz0 * (step(0.0, gy0) - 0.5);
vec4 gx1 = ixy1 / 7.0;
vec4 gy1 = fract(floor(gx1) / 7.0) - 0.5;
gx1 = fract(gx1);
vec4 gz1 = vec4(0.5) - abs(gx1) - abs(gy1);
vec4 sz1 = step(gz1, vec4(0.0));
gx1 -= sz1 * (step(0.0, gx1) - 0.5);
gy1 -= sz1 * (step(0.0, gy1) - 0.5);
vec3 g000 = vec3(gx0.x,gy0.x,gz0.x);
vec3 g100 = vec3(gx0.y,gy0.y,gz0.y);
vec3 g010 = vec3(gx0.z,gy0.z,gz0.z);
vec3 g110 = vec3(gx0.w,gy0.w,gz0.w);
vec3 g001 = vec3(gx1.x,gy1.x,gz1.x);
vec3 g101 = vec3(gx1.y,gy1.y,gz1.y);
vec3 g011 = vec3(gx1.z,gy1.z,gz1.z);
vec3 g111 = vec3(gx1.w,gy1.w,gz1.w);
vec4 norm0 = taylorInvSqrt(vec4(dot(g000, g000), dot(g010, g010), dot(g100, g100), dot(g110, g110)));
g000 *= norm0.x;
g010 *= norm0.y;
g100 *= norm0.z;
g110 *= norm0.w;
vec4 norm1 = taylorInvSqrt(vec4(dot(g001, g001), dot(g011, g011), dot(g101, g101), dot(g111, g111)));
g001 *= norm1.x;
g011 *= norm1.y;
g101 *= norm1.z;
g111 *= norm1.w;
float n000 = dot(g000, Pf0);
float n100 = dot(g100, vec3(Pf1.x, Pf0.yz));
float n010 = dot(g010, vec3(Pf0.x, Pf1.y, Pf0.z));
float n110 = dot(g110, vec3(Pf1.xy, Pf0.z));
float n001 = dot(g001, vec3(Pf0.xy, Pf1.z));
float n101 = dot(g101, vec3(Pf1.x, Pf0.y, Pf1.z));
float n011 = dot(g011, vec3(Pf0.x, Pf1.yz));
float n111 = dot(g111, Pf1);
vec3 fade_xyz = fade(Pf0);
vec4 n_z = mix(vec4(n000, n100, n010, n110), vec4(n001, n101, n011, n111), fade_xyz.z);
vec2 n_yz = mix(n_z.xy, n_z.zw, fade_xyz.y);
float n_xyz = mix(n_yz.x, n_yz.y, fade_xyz.x);
return 2.2 * n_xyz;
}
void main( void )
{
vec3 finaltCoord = (vec3( tCoord, 0.0 ) + tCoordOffset) * coordScale;
float n = abs( cnoise( finaltCoord ) ) * octMult.x + (abs(cnoise( finaltCoord * 2.0 )) / 2.0) * octMult.y + (abs(cnoise( finaltCoord * 4.0 )) / 4.0) * octMult.z;
gl_FragColor = vec4( vec3( n * colorMult.x, n * colorMult.y, n * colorMult.z ), 1.0);
}
Hope someone can shed some light on this...
Thanks!
Nils
