#version 460 core

layout (points) in;
layout (triangle_strip, max_vertices = 4) out;

in vec3 outColor[];
in vec2 outCenter[];
in float outAngle[];

out vec3 finalColor;

uniform mat4 mvp;

float scale = 10.0f;

vec2 SetOffset(int vertice){
    vec2 offset;
    switch(vertice){
        default: break;
        case 0: break;
        case 1: offset.x = scale; break;
        case 2: offset.y = scale; break;
        case 3: offset.x = scale; offset.y = scale; break;
    }
    return offset;
}

void createVertex(int vertice){
    float inX = gl_in[0].gl_Position.x;
    float inY = gl_in[0].gl_Position.y;

    vec2 result = SetOffset(vertice);

    float bRotX = inX * scale + result.x;
    float bRotY = inY * scale + result.y;

    vec2 center = outCenter[0];
    float cx = center.x;
    float cy = center.y;
    float inRad = radians(outAngle[0]);
    float cr = cos(inRad);
    float sr = sin(inRad);
    float endX = cr * bRotX - sr * bRotY;
    float endY = sr * bRotX + cr * bRotY;

    gl_Position = mvp * vec4(endX, endY, 1.0, 1.0);
    // ^--- Line that results a chaos if I add the centering to the variables. (vec2 center)
    // gl_Position = mvp * vec4(endX + center.x, endY + center.y, 1.0, 1.0);

    finalColor = outColor[0];
    EmitVertex();
}


void main(void){
    createVertex(0);
    createVertex(1);
    createVertex(2);
    createVertex(3);
    EndPrimitive();
}