//shader dotmatrix2_vertex

#version 440 core
layout(location = 0) in vec3 aPos;
layout(location = 1) in vec2 aUV;

out VS_OUT {
  vec2 uv;
} vs_out;

uniform mat4 transform;

void main() {
  gl_Position = transform * vec4(aPos, 1);
  vs_out.uv = aUV;
}

//shader dotmatrix2_fragment
#version 440 core
out vec4 FragColor;
in vec2 uv2;
in vec2 dots2;
flat in uvec2 dots3;

layout(shared, binding = 2) uniform DotMatrix {
  uvec2 dots;
  float k1;
  float k2;
  float k3;
  float max;
};

float fc(float x) { return (x+1)/2; }
float fd(float x) { return (2*x-1); }

float ntsf(float x,float k) {
  x = clamp(x,-1.0,1.0);
  return (x-x*k)/(k - abs(x) * 2.0 * k + 1.0);
}

float ntsf3(float x,float k1,float k2,float k3) {
  return fd(ntsf(fc(ntsf(fd(ntsf(fc(x),k1)),k2)),k3));
}

float ntsf3s(float x,float k1,float k2,float k3) {
  return sign(x) * ntsf3(2*abs(x)-1,k1,k2,k3)/2+0.5;
}

void main() {
  //  unsigned int c2 = int(dots2.x*4096);
  //unsigned int c1 = int(dots2.y*4096);
  unsigned int c2 = dots3.x;
  unsigned int c1 = dots3.y;

  //c1=0xaaaaaaaa;
  //c2=0x55555555;

#if 1
  float s = 1.0/8.0;
  unsigned int i=0;
  float v=0;
  for(float y=0;y<1;y+=s) {
    for(float x=0;x<1;x+=s) {
      vec2 p = (uv2-1.0/16.0);
      if((((i<32?c1:c2)>>(31-(i&31))) & 1) != 0) {
        float e = distance(vec2(x,y),p);
        if(e<max) {
          v +=  clamp(ntsf3s(1-e,k1,k2,k3),0,1)*1.5;
        }
      }
      i++;
    }
  }
#endif

  FragColor = vec4(vec3(0,1,0),v*0.5);
  //FragColor = vec4(vec3(1,0,0),1);
}

//shader dotmatrix2_geometry
#version 440 core
layout (triangles) in;
layout (triangle_strip, max_vertices = 100) out;
layout(shared, binding = 3) uniform DotMatrixFont {
  int px;
  int py;
  float size;
  uvec2 patterns[256];
};
layout(shared, binding = 4) uniform String {
  int string[256];
};

in VS_OUT {
  vec2 uv;
} gs_in[];

out vec2 uv2;
out vec2 dots2;
flat out uvec2 dots3;

void main() {
  int i;

  int count=0;
  for(int ci=0;;ci++) {
    int ch4 = string[ci];
    for(int bi=0;bi<4;bi++,ch4>>=8) {
      int ch = ch4 & 0xff;
      if(ch==0) {
	return;
      }
      dots3 = patterns[ch];
      for(i = 0; i < 3; i++) {
	uv2 = gs_in[i].uv;
	gl_Position = gl_in[i].gl_Position + vec4(count*size*6.0/8,0,0,0);
	EmitVertex();
      }
      EndPrimitive();
      count++;
    }
  }

}