Fixes in Perlin and Voronoi

Perlin and Voronoi have better randomness, and Voronoi color output is now tileable

addons/procedural_material/common.shader

@@ -18,7 +18,7 @@ float wave_constant(float x) {
 }
 
 float wave_sin(float x) {
-	return 0.5-0.5*cos(3.1415928*2.0*x);
+	return 0.5-0.5*cos(3.14159265359*2.0*x);
 }
 
 float wave_triangle(float x) {
@@ -122,6 +122,10 @@ vec3 blend_darken(vec2 uv, vec3 c1, vec3 c2, float opacity) {
 	return opacity*min(c1, c2) + (1.0-opacity)*c2;
 }
 
+vec3 blend_difference(vec2 uv, vec3 c1, vec3 c2, float opacity) {
+	return opacity*clamp(c2-c1, vec3(0.0), vec3(1.0)) + (1.0-opacity)*c2;
+}
+
 vec2 transform(vec2 uv, vec2 translate, float rotate, vec2 scale) {
 	vec2 rv;
 	uv -= vec2(0.5);
@@ -165,18 +169,18 @@ float colored_bricks(vec2 uv, vec2 count, float offset) {
 }
 
 float perlin(vec2 uv, vec2 size, int iterations, float persistence, int seed) {
-	uv += vec2(float(seed)*0.1234567);
+	vec2 seed2 = rand2(vec2(float(seed), 1.0-float(seed)));
     float rv = 0.0;
     float coef = 1.0;
     float acc = 0.0;
     for (int i = 0; i < iterations; ++i) {
     	vec2 step = vec2(1.0)/size;
-        float f0 = rand(floor(fract(uv)*size));
+		vec2 xy = seed2+floor(fract(uv)*size);
-        float f1 = rand(floor(fract(uv+vec2(step.x, 0.0))*size));
+        float f0 = rand(xy);
-        float f2 = rand(floor(fract(uv+vec2(0.0, step.y))*size));
+        float f1 = rand(xy+vec2(1.0, 0.0));
-        float f3 = rand(floor(fract(uv+vec2(step.x, step.y))*size));
+        float f2 = rand(xy+vec2(0.0, 1.0));
-        vec2 mixval = fract(uv*size);
+        float f3 = rand(xy+vec2(1.0, 1.0));
-        mixval = 0.5*(1.0-cos(3.1415928*mixval));
+        vec2 mixval = smoothstep(0.0, 1.0, fract(uv*size));
         rv += coef * mix(mix(f0, f1, mixval.x), mix(f2, f3, mixval.x), mixval.y);
         acc += coef;
         size *= 2.0;
@@ -187,7 +191,7 @@ float perlin(vec2 uv, vec2 size, int iterations, float persistence, int seed) {
 }
 
 vec4 voronoi(vec2 uv, vec2 size, float intensity, int seed) {
-	uv += vec2(float(seed)*0.1234567);
+	vec2 seed2 = rand2(vec2(float(seed), 1.0-float(seed)));
     uv *= size;
     float best_distance0 = 1.0;
     float best_distance1 = 1.0;
@@ -198,7 +202,7 @@ vec4 voronoi(vec2 uv, vec2 size, float intensity, int seed) {
     	for (int dy = -1; dy < 2; ++dy) {
             vec2 d = vec2(float(dx), float(dy));
             vec2 p = p0+d;
-            p += rand2(mod(p, size));
+            p += rand2(seed2+mod(p, size));
             float distance = length((uv - p) / size);
             if (best_distance0 > distance) {
             	best_distance1 = best_distance0;

addons/procedural_material/library.gd

@@ -16,7 +16,8 @@ func get_drag_data(position):
 		elif data.has("type") and data.type == "uniform":
 			preview = ColorRect.new()
 			preview.rect_size = Vector2(32, 32)
-			preview.color = Color(data.color.r, data.color.g, data.color.b, data.color.a)
+			if data.has("color"):
+				preview.color = Color(data.color.r, data.color.g, data.color.b, data.color.a)
 		else:
 			preview = Label.new()
 			preview.text = data.tree_item

addons/procedural_material/library/base.json

@@ -11,6 +11,10 @@
 		"tree_item":"Miscellaneous",
 		"collapsed":false
 	},
+	{
+		"tree_item":"Generators/Uniform",
+		"type":"uniform"
+	},
 	{
 		"tree_item":"Generators/Image",
 		"type":"image",

addons/procedural_material/nodes/blend.gd

@@ -15,7 +15,8 @@ const BLEND_TYPES = [
 	{ name="Burn", shortname="burn" },
 	{ name="Dodge", shortname="dodge" },
 	{ name="Lighten", shortname="lighten" },
-	{ name="Darken", shortname="darken" }
+	{ name="Darken", shortname="darken" },
+	{ name="Difference", shortname="difference" }
 ]
 
 func _ready():

addons/procedural_material/nodes/blend.tscn

@@ -80,7 +80,7 @@ group = null
 text = "Normal"
 flat = false
 align = 0
-items = [ "Normal", null, false, 0, null, "Dissolve", null, false, 1, null, "Multiply", null, false, 2, null, "Screen", null, false, 3, null, "Overlay", null, false, 4, null, "Hard Light", null, false, 5, null, "Soft Light", null, false, 6, null ]
+items = [ "Normal", null, false, 0, null, "Dissolve", null, false, 1, null, "Multiply", null, false, 2, null, "Screen", null, false, 3, null, "Overlay", null, false, 4, null, "Hard Light", null, false, 5, null, "Soft Light", null, false, 6, null, "Burn", null, false, 7, null, "Dodge", null, false, 8, null, "Lighten", null, false, 9, null, "Darken", null, false, 10, null ]
 selected = 0
 
 [node name="Label1" type="Label" parent="." index="1"]

addons/procedural_material/nodes/voronoi.gd

@@ -23,7 +23,7 @@ func _get_shader_code(uv, slot = 0):
 	elif slot == 1:
 		rv.f = name+"_"+str(variant_index)+"_xyzw.w"
 	else:
-		rv.rgb = "rand3("+name+"_"+str(variant_index)+"_xyzw.xy)"
+		rv.rgb = "rand3(fract("+name+"_"+str(variant_index)+"_xyzw.xy))"
 	return rv
 
 func _on_offset_changed():