雷电芽衣andClaude
c864304695
A layered image editor for Linux and Omarchy, ported from Compositor (github.com/robbietilton/Compositor), whose Swift source is its specification. It reads and writes Compositor's .comp projects. Packages for Ubuntu, Fedora and Arch come from the release workflow; scripts/install/ holds one install script per distribution family, and flake.nix serves NixOS. Co-Authored-By: Claude <noreply@anthropic.com>
38 lines
1.7 KiB
C
38 lines
1.7 KiB
C
#include "LensPixels.h"
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#include <math.h>
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void lens_distort(const uint8_t *source, uint8_t *destination, size_t width, size_t height, size_t stride, double k) {
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double cx = width * 0.5, cy = height * 0.5;
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double halfDiagonal2 = cx * cx + cy * cy;
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for (size_t y = 0; y < height; ++y) {
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double dy = y + 0.5 - cy;
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uint8_t *out = destination + y * stride;
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for (size_t x = 0; x < width; ++x) {
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double dx = x + 0.5 - cx;
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double scale = 1.0 - k * (dx * dx + dy * dy) / halfDiagonal2;
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// Source position in pixel-center coordinates.
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double sx = cx + dx * scale - 0.5, sy = cy + dy * scale - 0.5;
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double fx0 = floor(sx), fy0 = floor(sy);
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double fx = sx - fx0, fy = sy - fy0;
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long x0 = (long)fx0, y0 = (long)fy0;
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double sums[4] = {0, 0, 0, 0};
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for (int j = 0; j < 2; ++j) {
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long row = y0 + j;
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if (row < 0 || row >= (long)height) continue;
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double wy = j ? fy : 1 - fy;
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if (wy == 0) continue;
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const uint8_t *line = source + (size_t)row * stride;
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for (int i = 0; i < 2; ++i) {
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long column = x0 + i;
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if (column < 0 || column >= (long)width) continue;
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double weight = wy * (i ? fx : 1 - fx);
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if (weight == 0) continue;
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const uint8_t *p = line + (size_t)column * 4;
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for (int c = 0; c < 4; ++c) sums[c] += weight * p[c];
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}
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}
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for (int c = 0; c < 4; ++c) out[x * 4 + c] = (uint8_t)lround(sums[c]);
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}
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}
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}
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