in vec4 color;
in vec2 texCoord;
out vec4 fragColor;

uniform sampler2D tex;
uniform sampler2D mask_tex;

uniform float offset_x;
uniform float offset_y;
uniform float resolution_x;
uniform float resolution_y;
uniform float mask_resolution_x;
uniform float mask_resolution_y;

void main(void)
{
	vec4 col = texture2D(tex, texCoord);
	vec2 mask_coords = vec2((texCoord.x*resolution_x + offset_x)/mask_resolution_x, (texCoord.y*resolution_y + offset_y)/mask_resolution_y);
	vec4 mask = texture2D(mask_tex, mask_coords);
	fragColor = vec4(col.rgb, col.a*mask.a);
}