临时

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Shader/2DCircularOutline.gdshader

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+shader_type canvas_item;
+
+uniform bool allow_out_of_bounds = true;
+uniform float outline_thickness: hint_range(0.0, 16.0, 1.0) = 1.0;
+uniform vec4 outline_color: source_color = vec4(1.0);
+uniform int quality: hint_range(1, 3, 1) = 2; // 1=低质量但快速, 2=平衡, 3=高质量但慢
+uniform bool use_fast_mode = true; // 快速模式，牺牲一点质量换取性能
+
+bool is_inside_usquare(vec2 x) {
+	return x == clamp(x, vec2(0.0), vec2(1.0));
+}
+
+vec4 blend(vec4 bottom, vec4 top) {
+    float alpha = top.a + bottom.a * (1.0 - top.a);
+    if (alpha < 0.0001) return vec4(0.0);
+
+    vec3 color = mix(bottom.rgb * bottom.a, top.rgb, top.a) / alpha;
+    return vec4(color, alpha);
+}
+
+void vertex() {
+	if (allow_out_of_bounds) VERTEX += (UV * 2.0 - 1.0) * outline_thickness;
+}
+
+void fragment() {
+	if (outline_thickness <= 0.0 || outline_color.a <= 0.0) {
+		COLOR = texture(TEXTURE, UV);
+	} else {
+		vec2 uv = UV;
+		vec4 texture_color = texture(TEXTURE, UV);
+
+		if (allow_out_of_bounds) {
+			vec2 texture_pixel_size = vec2(1.0) / (vec2(1.0) / TEXTURE_PIXEL_SIZE + vec2(outline_thickness * 2.0));
+			uv = (uv - texture_pixel_size * outline_thickness) * TEXTURE_PIXEL_SIZE / texture_pixel_size;
+
+			if (is_inside_usquare(uv)) {
+				texture_color = texture(TEXTURE, uv);
+			} else {
+				texture_color = vec4(0.0);
+			}
+		}
+
+		// 如果当前像素已经有alpha，且不是在边缘，可以跳过复杂计算
+		if (texture_color.a > 0.9) {
+			COLOR = texture_color;
+		} else {
+			float alpha = 0.0;
+
+			if (use_fast_mode) {
+				// 快速模式：使用较少的采样点
+				float step_size = max(1.0, outline_thickness / 4.0);
+				int max_samples = 32; // 限制最大采样数
+				int sample_count = 0;
+
+				for (float radius = step_size; radius <= outline_thickness && sample_count < max_samples; radius += step_size) {
+					// 使用8个方向的采样点
+					vec2 directions[8] = {
+						vec2(1.0, 0.0), vec2(-1.0, 0.0), vec2(0.0, 1.0), vec2(0.0, -1.0),
+						vec2(0.707, 0.707), vec2(-0.707, 0.707), vec2(0.707, -0.707), vec2(-0.707, -0.707)
+					};
+
+					for (int i = 0; i < 8; i++) {
+						vec2 sample_uv = uv + directions[i] * radius * TEXTURE_PIXEL_SIZE;
+						if (is_inside_usquare(sample_uv)) {
+							float sample_alpha = texture(TEXTURE, sample_uv).a;
+							alpha = max(alpha, sample_alpha);
+							sample_count++;
+							if (alpha > 0.99) break; // 早期退出
+						}
+					}
+					if (alpha > 0.99) break; // 早期退出
+				}
+			} else {
+				// 原始高质量模式，但有优化
+				int max_thickness = int(min(outline_thickness, float(8 + quality * 4))); // 限制最大厚度
+
+				for (int y = 1; y <= max_thickness; y++) {
+					for (int x = 0; x <= y; x++) {
+						float dist = length(vec2(float(x), float(y) - 0.5));
+						if (dist > outline_thickness) break;
+
+						vec2 offsets[8] = {
+							vec2(float(x), float(y)), vec2(float(-x), float(y)),
+							vec2(float(x), float(-y)), vec2(float(-x), float(-y)),
+							vec2(float(y), float(x)), vec2(float(-y), float(x)),
+							vec2(float(y), float(-x)), vec2(float(-y), float(-x))
+						};
+
+						for (int i = 0; i < 8; i++) {
+							vec2 sample_uv = uv + offsets[i] * TEXTURE_PIXEL_SIZE;
+							if (is_inside_usquare(sample_uv)) {
+								float sample_alpha = texture(TEXTURE, sample_uv).a;
+								alpha = max(alpha, sample_alpha);
+								if (alpha > 0.99) break; // 早期退出
+							}
+						}
+
+						if (alpha > 0.99) break; // 早期退出
+					}
+
+					if (alpha > 0.99) break; // 早期退出
+				}
+			}
+
+			COLOR = blend(vec4(outline_color.rgb, alpha * outline_color.a), texture_color);
+		}
+	}
+}