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

// 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;

// DEFISH
float PI = 3.14159265358979;
float _THETA_S_Y_SCALE = 640.0/720.0;//(1080.0 / 1920.0);

float radius    = 1.0;
//uniform vec4 uvOffset;
//uniform vec2 radiusOffset;
uniform mat4 tune360;   // [0] = left [wzr], [1] right [yxr]
uniform int resolution;     // 0:FHD, 1:HD, 2:SD

void main(void)
{
    vec2 st = v_TexCoords0.st;
    bool front = (tune360[0][0] > 0.5);

    vec2 fc;
    if (front)
    {
        fc = vec2(st.x,min(st.y*0.5,0.499));    // 이거 왜하는거지???
    }
    else
    {
        fc = vec2(st.x,0.5001+st.y*0.5);
    }

    // CLIP LEFT 1PX
    if(resolution == 2)
    {
        //fc.x = clamp(fc.x,0.0,0.90);
        //gl_FragColor = vec4(1.0,0.0,0.0,1.0);
        //return;
    }

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