#ifdef GL_ES
precision mediump float;
#endif

// OF built-in attributes.

uniform mat4 modelViewMatrix;

// Custom attributes.

uniform sampler2D uDepthTex; // Sampler for the depth space data
uniform sampler2D uWorldTex; // Transformation from kinect depth/color space to kinect world space
uniform sampler2D u_particle;

uniform ivec2 uFrameSize;
uniform ivec2 uDepthFrameSize;

uniform vec2 u_resolution;

out vec4 vPosition;
out vec2 vTexCoord;
flat out int vValid;

out float vTemperature;

void main()
{
    vTexCoord = vec2(gl_InstanceID % uFrameSize.x, gl_InstanceID / uFrameSize.x) / uDepthFrameSize;

    vValid = 1;

    // vValid = (depth != 0 && ray.x != 0 && ray.y != 0) ? 1 : 0;

    vec4 posWorld = texture2D(u_particle, vTexCoord);

    vTemperature = posWorld.w;

    posWorld.w = 1;

    // posWorld.xyz *= 65535;
    // // posWorld.xy = vTexCoord * 10000;
    // // posWorld.xy = posWorld.xz * 0.1;
    // // posWorld.z = 10;
    // vValid = posWorld.w > 0.0 ? 1 : 0;

    // posWorld.w = 1;

    // Flip X as OpenGL and K4A have different conventions on which direction is positive.
    // posWorld.x *= -1;

    vPosition = modelViewMatrix * posWorld;
}