shader_type spatial;
// Persistent blood splats, drawn as one MultiMesh of flat quads (see blood_decals.gd).
// Unshaded and nearest-filtered to sit inside the PS1 look; alpha-blended so overlapping
// splats pool darker. depth_draw_never + the small normal offset the pool bakes into each
// transform keep the coplanar floor/wall quads from z-fighting the surface they stain.
render_mode unshaded, cull_disabled, shadows_disabled, depth_draw_never, blend_mix;

uniform sampler2D atlas : source_color, filter_nearest;
// Number of splat shapes packed side-by-side in the atlas (one row).
uniform int cells = 8;

varying flat float v_cell;
varying flat float v_shade;

void vertex() {
	// x = which atlas shape this instance uses; y = per-instance brightness (fresh vs old).
	v_cell  = INSTANCE_CUSTOM.x;
	v_shade = INSTANCE_CUSTOM.y;
}

void fragment() {
	float u = (UV.x + v_cell) / float(cells);
	vec4 c = texture(atlas, vec2(u, UV.y));
	ALBEDO = c.rgb * v_shade;
	ALPHA = c.a;
}