b9c7e1bdd9
While here, do not interpolate style properties that are not transitionable. The previous behavior was to switch from old to new value halfway through the transition; now the new value is used immediately, as in JS.
63 lines
1.8 KiB
C++
63 lines
1.8 KiB
C++
#include <mbgl/geometry/resample.hpp>
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#include <mbgl/util/interpolate.hpp>
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#include <cmath>
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namespace mbgl {
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const float minScale = 0.5f;
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const std::array<std::vector<float>, 4> minScaleArrays = {{
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/*1:*/ { minScale },
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/*2:*/ { minScale, 2 },
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/*4:*/ { minScale, 4, 2, 4 },
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/*8:*/ { minScale, 8, 4, 8, 2, 8, 4, 8 }
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}};
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Anchors resample(const std::vector<Coordinate> &vertices, float spacing,
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const float /*minScale*/, float maxScale, const float tilePixelRatio,
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const int start) {
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maxScale = std::round(std::fmax(std::fmin(8.0f, maxScale / 2.0f), 1.0f));
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spacing *= tilePixelRatio / maxScale;
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const size_t index = util::clamp<size_t>(std::floor(std::log(maxScale) / std::log(2)), 0, minScaleArrays.size() - 1);
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const std::vector<float> &minScales = minScaleArrays[index];
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const size_t len = minScales.size();
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float distance = 0.0f;
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float markedDistance = 0.0f;
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int added = start;
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Anchors points;
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auto end = vertices.end() - 1;
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int i = 0;
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for (auto it = vertices.begin(); it != end; it++, i++) {
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const Coordinate &a = *(it), b = *(it + 1);
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float segmentDist = util::dist<float>(a, b);
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float angle = util::angle_to(b, a);
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while (markedDistance + spacing < distance + segmentDist) {
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markedDistance += spacing;
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float t = (markedDistance - distance) / segmentDist,
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x = util::interpolate(a.x, b.x, t),
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y = util::interpolate(a.y, b.y, t),
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s = minScales[added % len];
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if (x >= 0 && x < 4096 && y >= 0 && y < 4096) {
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points.emplace_back(x, y, angle, s, i);
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}
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added++;
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}
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distance += segmentDist;
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}
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return points;
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}
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}
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