Grid shader rework

level_designer/viewport/grid.gdshader

@@ -2,31 +2,47 @@ shader_type canvas_item;
 
 global uniform vec2 VIEWPORT_SIZE;
 
-uniform sampler2D grid_bg_texture : repeat_enable, filter_nearest;
-uniform sampler2D grid_origin_texture : repeat_enable, filter_nearest;
-uniform vec4 grid_bg_modulate : source_color = vec4(1.0);
-uniform vec4 grid_origin_modulate : source_color = vec4(1.0);
+uniform vec2 cell_size = vec2(32.0);
+uniform vec2 line_thickness = vec2(2.0);
 
-uniform vec2 grid_offset = vec2(0.0);
+uniform vec4 line_color : source_color = vec4(0.5);
+uniform vec4 bg_color : source_color = vec4(0);
 uniform float grid_fade_threshold : hint_range(0.0, 4.0) = 2.0;
 
+uniform vec2 grid_offset = vec2(0.0);
 uniform vec2 camera_position = vec2(0.0);
 uniform vec2 camera_zoom = vec2(1.0);
 
+// Function to get the color of grid at a given UV. Grid repeats every 1, 1 UV
+vec4 grid(vec2 uv) {
+	// We will be working within a tile, since they repeat
+	vec2 uv_within_tile = mod(uv, 1);
+
+	// Measure distance of tile_uv from 0.5 (center of the tile)
+	vec2 uv_distance_from_center = abs(vec2(0.5) - uv_within_tile);
+
+	// This distance must be less than this to lie on the line.
+	vec2 line_uv_thickness = line_thickness/(2.0*cell_size);
+
+	bool is_on_horizontal_line = uv_distance_from_center.y < line_uv_thickness.y;
+	bool is_on_vertical_line = uv_distance_from_center.x < line_uv_thickness.x;
+
+	if (is_on_horizontal_line || is_on_vertical_line) {
+		return line_color;
+	} else {
+		return bg_color;
+	}
+}
 
 void fragment() {
-	vec2 tex_size = vec2(textureSize(grid_bg_texture, 0));
-
+	// Find the tiled UV at this world position.
 	vec2 world_pos = (UV * VIEWPORT_SIZE) / camera_zoom + camera_position - (VIEWPORT_SIZE * 0.5) / camera_zoom;
-	vec2 offset_pos = world_pos - grid_offset + tex_size;
-	vec2 tiled_uv = offset_pos / tex_size;
-
-	vec2 cell = floor(offset_pos / tex_size);
-	bool near_origin = (cell == vec2(0.0));
+	vec2 offset_pos = world_pos - grid_offset + cell_size;
+	vec2 tiled_uv = offset_pos / cell_size;
 
+	// BG is made more transparent when zoomed out
 	float bg_alpha = smoothstep(0.0, grid_fade_threshold, camera_zoom.x);
-	vec4 bg = texture(grid_bg_texture, tiled_uv) * grid_bg_modulate * vec4(1.0, 1.0, 1.0, bg_alpha);
-	vec4 origin = texture(grid_origin_texture, tiled_uv) * grid_origin_modulate;
-
-	COLOR = mix(bg, origin, float(near_origin) * origin.a);
+	// The grid function gets the color at this UV. 
+	// This is multiplied with the alpha value above.
+	COLOR = grid(tiled_uv) * vec4(1.0, 1.0, 1.0, bg_alpha);
 }

level_designer/viewport/viewport.tscn

@@ -1,18 +1,17 @@
 [gd_scene format=3 uid="uid://ob44gpnyj5ja"]
 
 [ext_resource type="Shader" uid="uid://sxvlfpblfmai" path="res://level_designer/viewport/grid.gdshader" id="1_2bfex"]
-[ext_resource type="Texture2D" uid="uid://5d1xg84rwu1k" path="res://level_designer/viewport/grid.png" id="1_3d3a7"]
 [ext_resource type="Script" uid="uid://bhcjxobw61v12" path="res://level_designer/viewport/ld_camera.gd" id="2_3d3a7"]
 [ext_resource type="Script" uid="uid://dnq5lwh60selk" path="res://level_designer/viewport/grid.gd" id="3_2bfex"]
 
 [sub_resource type="ShaderMaterial" id="ShaderMaterial_bu805"]
 shader = ExtResource("1_2bfex")
-shader_parameter/grid_bg_texture = ExtResource("1_3d3a7")
-shader_parameter/grid_origin_texture = ExtResource("1_3d3a7")
-shader_parameter/grid_bg_modulate = Color(0, 0, 0, 0.2)
-shader_parameter/grid_origin_modulate = Color(0, 0, 0, 1)
-shader_parameter/grid_offset = Vector2(0, 0)
+shader_parameter/cell_size = Vector2(32, 32)
+shader_parameter/line_thickness = Vector2(2, 2)
+shader_parameter/line_color = Color(0.5, 0.5, 0.5, 0.5)
+shader_parameter/bg_color = Color(0, 0, 0, 0)
 shader_parameter/grid_fade_threshold = 1.0000000475
+shader_parameter/grid_offset = Vector2(0, 0)
 shader_parameter/camera_position = Vector2(0, 0)
 shader_parameter/camera_zoom = Vector2(1, 1)