// Simple Texture Shader

#type vertex
#version 430

layout(location = 0) in vec3 a_Position;
layout(location = 4) in vec2 a_TexCoord;

uniform mat4 u_MVP;

out vec2 v_TexCoord;

void main()
{
    vec4 position = u_MVP * vec4(a_Position, 1.0);
    gl_Position = position;

    v_TexCoord = a_TexCoord;
}

#type fragment
#version 430

layout(location = 0) out vec4 color;

uniform sampler2D u_Texture;
uniform float u_Scale;
uniform float u_Res;

in vec2 v_TexCoord;

/*void main()
{
	color = texture(u_Texture, v_TexCoord * 8.0);
}*/

float grid(vec2 st, float res)
{
    vec2 grid = fract(st);
    return step(res, grid.x) * step(res, grid.y);
}

void main()
{
    float scale = u_Scale;
    float resolution = u_Res;

    float x = grid(v_TexCoord * scale, resolution);
    color = vec4(vec3(0.2), 0.5) * (1.0 - x);
}