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