Texture coordinates

[Store]

Hey guys
i’m here to get a little help from shader experts
do you think i messed up this code? cause it’s giving me something like “colour sample patch” as output instead of shader output!
i mean this is a really simple and short code but why is this happening? something wrong with the coordinates? a difference between spark and shadertoy corrdinate system maybe?

precision highp float;

vec4 F (vec2 U, std::Texture2d iChannel1)
{
    vec2 R = std::getRenderTargetSize();
         U = fragment(floor(std::getRenderTargetSize() * std::getVertexTexCoord()));
    return iChannel1.sample(U/R.xy);
}
float ln (vec2 p, vec2 a, vec2 b)
{
    return length(p-a-(b-a)*clamp(dot(p-a,b-a)/dot(b-a,b-a),0.,1.));
}
vec4 T (vec2 U, std::Texture2d iChannel0, std::Texture2d iChannel1)
{
    vec2 R = std::getRenderTargetSize();
         U = fragment(floor(std::getRenderTargetSize() * std::getVertexTexCoord()));
    U -= F(U, iChannel1).xy;
    U -= F(U, iChannel1).xy;
    return iChannel0.sample(U/R.xy);
}
void mainImage( in float iFrame, in std::Texture2d iChannel0, in std::Texture2d iChannel1, out vec4 Q )
{
    vec2 R = std::getRenderTargetSize();
    vec2 U = fragment(floor(std::getRenderTargetSize() * std::getVertexTexCoord()));

    Q = 0.25 *
             (T(U + vec2(1.0, 0.0), iChannel0, iChannel1) +
              T(U - vec2(1.0, 0.0), iChannel0, iChannel1) +
              T(U + vec2(0.0, 1.0), iChannel0, iChannel1) +
              T(U - vec2(0.0, 1.0), iChannel0, iChannel1));
    
    if (U.x<2.||U.y<2.||R.x-U.x<2.||R.y-U.y<2.||iFrame < 1.0)
    Q = vec4(U, 0.0, 0.0);
}

[josh_beckwith]

Can you link to the shadertoy?

[Store]

it was a while ago and i lost the shadertoy link

[josh_beckwith]

I’m not sure what the channel outputs are supposed to be, or what the output is supposed to look like, but I’m getting a camera texture with a little yellow border.

test-shader.arprojpkg (21.2 KB)

[Store]

actually it is supposed to be a water simulation filter but first buffer shows the “colour sample” like thing and rest of the shaders show nothing
i can only think of wrong or messed up coordinates but everything is correct.
here is the complete code.
project file

[josh_beckwith]

I’m not sure where the problem is. The mouse position color sampler buffer wasn’t even working in that project you uploaded. I simplified the code a bit (not sure what that T function is doing, seems redundant). The main issue in that buffer was that the iMouse value was in pixels and it was being used to sample from a texture (which should be sampled in normalized coordinates)

If that’s the case, maybe the same thing is happening elsewhere in the code.

precision highp float;

// mouse

float ln (vec2 p, vec2 a, vec2 b)
{
    return length(p-a-(b-a)*clamp(dot(p-a,b-a)/dot(b-a,b-a),0.,1.));
}
void mainImage( in vec4 iMouse, in std::Texture2d BufferC, out vec4 C )
{
    vec2 R = std::getRenderTargetSize();
    vec2 U = fragment(std::getVertexTexCoord());

    vec4 M = iMouse;
    M.xy /= R;
    vec4 p = BufferC.sample(U);
    if (M.z>0.)
    {
        if (p.z>0.)
        C =  vec4(M.xy, p.xy);
        else
        C =  vec4(M.xy, M.xy);
    }
    else C = vec4(-R.xy, -R.xy);
}