Tiled texture plus offset texture overlay
I made this to explain how to offset and overlay a second texture over another at someone’s request.
Shader code
shader_type canvas_item;
uniform sampler2D white_texture: source_color, hint_default_white;
uniform float white_tile_frequency = 2.0;
uniform sampler2D red_texture: source_color, hint_default_black;
uniform vec2 red_begin = vec2(0.25, 0.25);
uniform vec2 red_end = vec2(0.75, 0.75);
void fragment() {
vec2 white_uv_tiled = mod(UV * white_tile_frequency, 1.0);
vec2 red_range = red_end - red_begin;
vec2 red_uv = (UV - red_begin) / red_range;
vec4 red_texture_color = texture(red_texture, red_uv);
// rather than using an if statement, do some convoluted math with step
// red_bound is 1.0 when inside the red's bounding rectangle, and 0.0 outside
vec2 red_bound_top = step(1.0, red_uv);
vec2 red_bound_lower = 1.0 - step(0.0, red_uv);
float red_bound = clamp(1.0-(red_bound_top.x + red_bound_top.y + red_bound_lower.x + red_bound_lower.y), 0.0, 1.0);
COLOR = mix(texture(white_texture, white_uv_tiled), red_texture_color, red_texture_color.a * red_bound);
}