layout (binding = TEX_ATLAS) uniform sampler2DArray tex_atlas;

struct AtlasPart {
	vec2 uv0;
	vec2 uv1;
	int zpos;
	int edges; // 0 = repeat, 1 = clamp
};

layout(std140, binding = SSBO_ATLAS_BUFFER) readonly buffer AtlasBuffer {
	AtlasPart atlas[];
};

vec4 atlas_read_texture(uint tex, vec2 uv) {
	AtlasPart a = atlas[tex];
	uv = (a.edges == 0 ? fract(uv) : clamp(uv, 0.f, 1.f)) * (a.uv1 - a.uv0) + a.uv0;
	return texture(tex_atlas, vec3(uv, a.zpos));
}