Add the original shader code top colors.gd aswell.

game/addons/mat_maker_gd/nodes/common/colors.gd

@@ -3,6 +3,22 @@ extends Reference
 
 const Commons = preload("res://addons/mat_maker_gd/nodes/common/commons.gd")
 
+#adjust_hsv.mmg
+#brightness_contrast.mmg
+#greyscale.mmg
+
+#main node methods: adjust_hsv, brightness_contrast
+
+#vec3 rgb_to_hsv(vec3 c) {
+#	vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+#	vec4 p = c.g < c.b ? vec4(c.bg, K.wz) : vec4(c.gb, K.xy);
+#	vec4 q = c.r < p.x ? vec4(p.xyw, c.r) : vec4(c.r, p.yzx);
+#
+#	float d = q.x - min(q.w, q.y);
+#	float e = 1.0e-10;
+#	return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
+#}
+
 static func rgb_to_hsv(c : Vector3) -> Vector3:
 	var K : Color = Color(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
 	
@@ -25,6 +41,12 @@ static func rgb_to_hsv(c : Vector3) -> Vector3:
 	
 	return Vector3(abs(q.b + (q.a - q.g) / (6.0 * d + e)), d / (q.r + e), q.r);
 
+#vec3 hsv_to_rgb(vec3 c) {
+#	vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+#	vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+#	return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+#}
+
 static func hsv_to_rgb(c : Vector3) -> Vector3:
 	var K : Color = Color(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
 	
@@ -32,6 +54,18 @@ static func hsv_to_rgb(c : Vector3) -> Vector3:
 	
 	return c.z * lerp(Vector3(K.r, K.r, K.r), Commons.clampv3(p - Vector3(K.r, K.r, K.r), Vector3(), Vector3(1, 1, 1)), c.y);
 
+#adjust_hsv.mmg
+
+#vec4 $(name_uv)_rbga = $in($(uv));
+#vec3 $(name_uv)_hsv = rgb_to_hsv($(name_uv)_rbga.rgb);
+#$(name_uv)_hsv.x += $(hue);
+#$(name_uv)_hsv.y = clamp($(name_uv)_hsv.y*$(saturation), 0.0, 1.0);
+#$(name_uv)_hsv.z = clamp($(name_uv)_hsv.z*$(value), 0.0, 1.0);
+
+#hue, min: -0.5, max: 0.5, step: 0, default: 0
+#saturation, min: 0, max: 2, step: 0, default: 1
+#value, min: 0, max: 2, step: 0, default: 1
+
 static func adjust_hsv(color : Color, hue : float, saturation : float, value : float) -> Color:
 	var hsv : Vector3 = rgb_to_hsv(Vector3(color.r, color.g, color.b));
 	
@@ -43,6 +77,11 @@ static func adjust_hsv(color : Color, hue : float, saturation : float, value : f
 
 	return Color(h.x, h.y, h.z, color.a);
 
+#brightness, min: -1, max: 1, step: 0.01, default: 0
+#contrast, min: -1, max: 1, step: 0.01, default: 1
+
+#vec4(clamp($in($uv).rgb*$contrast+vec3($brightness)+0.5-$contrast*0.5, vec3(0.0), vec3(1.0)), $in($uv).a)
+
 static func brightness_contrast(color : Color, brightness : float, contrast : float) -> Color:
 	var bv : Vector3 = Vector3(brightness, brightness, brightness)
 	var cvv : Vector3 = Vector3(color.r * contrast, color.g * contrast, color.b * contrast)
@@ -53,18 +92,38 @@ static func brightness_contrast(color : Color, brightness : float, contrast : fl
 	
 	return Color(v.x, v.y, v.z, 1);
 
+#float gs_min(vec3 c) {
+#	return min(c.r, min(c.g, c.b));
+#}
+
 static func grayscale_min(c : Vector3) -> float:
 	return min(c.x, min(c.y, c.z));
 
+#float gs_max(vec3 c) {
+#	return max(c.r, max(c.g, c.b));
+#}
+
 static func grayscale_max(c : Vector3) -> float:
 	return max(c.x, max(c.y, c.z));
 
+#float gs_lightness(vec3 c) {
+#	return 0.5*(max(c.r, max(c.g, c.b)) + min(c.r, min(c.g, c.b)));
+#}
+
 static func grayscale_lightness(c : Vector3) -> float:
 	return 0.5*(max(c.x, max(c.y, c.z)) + min(c.x, min(c.y, c.z)));
 
+#float gs_average(vec3 c) {
+#	return 0.333333333333*(c.r + c.g + c.b);
+#}
+
 static func grayscale_average(c : Vector3) -> float:
 	return 0.333333333333*(c.x + c.y + c.z);
 
+#float gs_luminosity(vec3 c) {
+#	return 0.21 * c.r + 0.72 * c.g + 0.07 * c.b;
+#}
+
 static func grayscale_luminosity(c : Vector3) -> float:
 	return 0.21 * c.x + 0.72 * c.y + 0.07 * c.z;