Make alpha affect all of the blend modes besides Normal and Screen

There may still be some semi-transparency issues in blend modes, some extra testing is required

src/Shaders/BlendLayers.gdshader

@@ -55,12 +55,11 @@ vec3 rgb_to_hsl(vec3 rgb)
 
 
 vec4 blend(int blend_type, vec4 current_color, vec4 prev_color, float opacity) {
-	vec4 result;
-	if (current_color.a <= 0.001 || opacity <= 0.001) {
+	current_color.a *= opacity;  // Combine the layer opacity
+	if (current_color.a <= 0.001) {
 		return prev_color;
 	}
-	current_color.rgb = current_color.rgb * opacity; // Premultiply with the layer texture's alpha to prevent semi transparent pixels from being too bright (ALL LAYER TYPES!)
-	current_color.a = current_color.a * opacity;  // Combine the layer opacity
+	vec4 result;
 	switch(blend_type) {
 		case 1: // Darken
 			result.rgb = min(prev_color.rgb, current_color.rgb);
@@ -78,7 +77,7 @@ vec4 blend(int blend_type, vec4 current_color, vec4 prev_color, float opacity) {
 			result.rgb = max(prev_color.rgb, current_color.rgb);
 			break;
 		case 6: // Screen
-			result.rgb = mix(prev_color.rgb, 1.0 - (1.0 - prev_color.rgb) * (1.0 - current_color.rgb), current_color.a);
+			result.rgb = 1.0 - (1.0 - prev_color.rgb) * (1.0 - current_color.rgb);
 			break;
 		case 7: // Color dodge
 			result.rgb = prev_color.rgb / (1.0 - current_color.rgb);
@@ -128,9 +127,10 @@ vec4 blend(int blend_type, vec4 current_color, vec4 prev_color, float opacity) {
 			result.rgb = hsl_to_rgb(vec3(prev_hsl.r, prev_hsl.g, current_hsl.b));
 			break;
 		default: // Normal (case 0)
-			result.rgb = prev_color.rgb * (1.0 - current_color.a) + current_color.rgb;
+			result.rgb = current_color.rgb;
 			break;
 	}
+	result.rgb = mix(prev_color.rgb, result.rgb, current_color.a);
 	result.a = prev_color.a * (1.0 - current_color.a) + current_color.a;
 	result = clamp(result, 0.0, 1.0);
 	return mix(current_color, result, prev_color.a);

src/Tools/DesignTools/LineTool.tscn

@@ -9,13 +9,12 @@ script = ExtResource("2")
 
 [node name="ThicknessSlider" parent="." index="2" instance=ExtResource("3")]
 layout_mode = 2
-focus_mode = 2
-theme_type_variation = &"ValueSlider"
 min_value = 1.0
 value = 1.0
 prefix = "Size:"
 suffix = "px"
-is_global = true
+global_increment_action = "brush_size_increment"
+global_decrement_action = "brush_size_decrement"
 
 [node name="Brush" parent="." index="3"]
 visible = false

src/UI/Timeline/AnimationTimeline.gd

@@ -116,7 +116,7 @@ func _notification(what: int) -> void:
 		drag_highlight.hide()
 	elif what == NOTIFICATION_THEME_CHANGED:
 		if is_instance_valid(layer_settings_container):
-			layer_container.custom_minimum_size.x = layer_settings_container.size.x
+			layer_container.custom_minimum_size.x = layer_settings_container.size.x + 12
 
 
 func _input(event: InputEvent) -> void: