46 lines
1.2 KiB
Rust
46 lines
1.2 KiB
Rust
use super::CodePiece;
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use crate::impl_code_piece;
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use glsl::syntax::ShaderStage;
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use glsl::syntax::TranslationUnit;
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use glsl::transpiler::glsl::show_translation_unit;
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use glsl_quasiquote::glsl;
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pub struct Mercator(pub ShaderStage);
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impl Mercator {
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pub fn new() -> Self {
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let raw = glsl! {
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uniform float R;
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vec2 mercatorProject(vec2 loc) {
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// 将经纬度从度转换为弧度
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float lonRad = radians(loc.x);
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float latRad = radians(loc.y);
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// X轴投影 (线性映射经度)
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float x = R * lonRad;
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// Y轴投影 (非线性映射纬度)
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float y = R * log(tan(latRad / 2.0 + radians(45.0)));
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return vec2(x, y);
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}
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vec2 mercatorInverse(vec2 loc) {
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// 计算经度 (lon)，线性反映射
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float lon = degrees(loc.x / R); // 将弧度转换为度数
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// 计算纬度 (lat)，非线性反映射
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float lat = degrees(2.0 * atan(exp(loc.y / R)) - radians(90.0));
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return vec2(lon, lat); // 返回经纬度 (lon, lat)
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}
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};
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Self(raw)
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}
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}
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impl_code_piece!(Mercator, 0);
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