uniform sampler2D u_Texture0;
uniform sampler2D u_Texture1;
uniform sampler2D u_Texture2;

// https://qiita.com/zinziroge/items/3676b4e0f7715fa60336
// C:\Users\jeong\testing\theta_uvc_blender_mdk_ver.0.3.0
// https://gist.github.com/dinhnhat0401/12910a5fee2e380051c55e5db752b279


varying vec2 v_TexCoords0;
varying vec2 v_TexCoords1;
varying vec2 v_TexCoords2;

#define v_TexCoords1 v_TexCoords0
#define v_TexCoords2 v_TexCoords0
#define v_TexCoords3 v_TexCoords0

uniform float u_opacity;
uniform mat4 u_colorMatrix;

uniform mat3 tune360;

void main(void)
{
    vec2 fc = v_TexCoords0.st;
    vec2 src;

    // Y 축은 상단이 1.0, 하단이 0.0
    // 원점 확인
    if(fc.x < 0.5) // left
    {
        // 좌측 이미지(0.5,1.0)-> 상단이미지(1.0,0.5)
        src = vec2(fc.x*2.0,0.5+(fc.y*0.5));
    }
    else // right
    {
        // 후측 이미지(0.5,1.0)-> 상단이미지(1.0,0.5)
        src = vec2((fc.x*2.0)-1.0,fc.y*0.5);
    }


    gl_FragColor = clamp(u_colorMatrix
                             * vec4(texture2D(u_Texture0, src).r,
                                    texture2D(u_Texture1, src).r,
                                    texture2D(u_Texture2, src).r,
                                    1.0), 0.0, 1.0);
}