#version 410

in vec2 xy;
in vec2 uv;


// part attrs
in float partSlot;
uniform sampler2D partValues;
uniform float partIndex_color;

// part transform, in four columns
uniform float partIndex_colorA;
uniform float partIndex_colorB;
uniform float partIndex_shape;  // xyzw-> radiusLow, radiusHigh, alpha, currentValue

out vec2 uvV;

// per-part settings
out vec4 colorA;
out vec4 colorB;
out float radiusLow;
out float radiusHigh;
out float alpha;
out float currentValue;

void main(void)
{
    // Draw against the very back of the visible cube.
    float z = 0.999999;
    vec4 pos = vec4(xy.x, xy.y, z, 1.0);
    gl_Position = pos;
    
    // pass uv right through
    uvV = uv;
    
    // pass the part values through, too
    colorA = texture(partValues, vec2(partIndex_colorA, partSlot));
    colorB = texture(partValues, vec2(partIndex_colorB, partSlot));
    vec4 shape = texture(partValues, vec2(partIndex_shape, partSlot));
    radiusLow = shape.x;
    radiusHigh = shape.y;
    alpha = shape.z;
    currentValue = shape.w;
}