SiandClaude Opus 5.5
53dca6b4b8
Blur's box blur moves to effects/box_blur.hpp so both share it; Blur renders exactly as before. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
81 lines
2.8 KiB
C++
81 lines
2.8 KiB
C++
#pragma once
|
|
|
|
#include <algorithm>
|
|
#include <cstdint>
|
|
#include <string>
|
|
#include <utility>
|
|
|
|
#include "core/image.hpp"
|
|
#include "core/parallel.hpp"
|
|
|
|
namespace effector {
|
|
|
|
// One separable box blur pass. `stride` is the distance in bytes between two
|
|
// neighbouring samples along the blurred axis, `count` how many of them there
|
|
// are; the window is clamped at both ends.
|
|
inline void boxPass(const std::uint8_t* in, std::uint8_t* out, int count, std::size_t stride,
|
|
int radius) {
|
|
const int window = 2 * radius + 1;
|
|
int sum[3] = {0, 0, 0};
|
|
|
|
for (int c = 0; c < 3; ++c) {
|
|
sum[c] = in[c] * (radius + 1);
|
|
for (int i = 1; i <= radius; ++i) {
|
|
sum[c] += in[static_cast<std::size_t>(std::min(i, count - 1)) * stride + c];
|
|
}
|
|
}
|
|
|
|
for (int i = 0; i < count; ++i) {
|
|
for (int c = 0; c < 3; ++c) {
|
|
out[static_cast<std::size_t>(i) * stride + c] =
|
|
static_cast<std::uint8_t>(sum[c] / window);
|
|
}
|
|
const int add = std::min(i + radius + 1, count - 1);
|
|
const int drop = std::max(i - radius, 0);
|
|
for (int c = 0; c < 3; ++c) {
|
|
sum[c] += in[static_cast<std::size_t>(add) * stride + c] -
|
|
in[static_cast<std::size_t>(drop) * stride + c];
|
|
}
|
|
}
|
|
}
|
|
|
|
inline void blurHorizontal(const Image& src, Image& dst, int radius) {
|
|
parallelFor(static_cast<std::size_t>(src.height()), [&](std::size_t begin, std::size_t end) {
|
|
for (std::size_t y = begin; y < end; ++y) {
|
|
boxPass(src.row(static_cast<int>(y)), dst.row(static_cast<int>(y)), src.width(), 3,
|
|
radius);
|
|
}
|
|
});
|
|
}
|
|
|
|
inline void blurVertical(const Image& src, Image& dst, int radius) {
|
|
const std::size_t stride = src.stride();
|
|
parallelFor(static_cast<std::size_t>(src.width()), [&](std::size_t begin, std::size_t end) {
|
|
for (std::size_t x = begin; x < end; ++x) {
|
|
const std::size_t offset = x * 3;
|
|
boxPass(src.data() + offset, dst.data() + offset, src.height(), stride, radius);
|
|
}
|
|
});
|
|
}
|
|
|
|
// Blurs `canvas` in place: `passes` box blurs of `radius` along the axes
|
|
// `direction` names ("both", "horizontal" or "vertical"). Shared by the blur
|
|
// and the focus pull effects.
|
|
inline void boxBlur(Image& canvas, int radius, int passes, const std::string& direction) {
|
|
const int width = canvas.width();
|
|
const int height = canvas.height();
|
|
Image scratch(width, height);
|
|
for (int pass = 0; pass < passes; ++pass) {
|
|
if (direction != "vertical") {
|
|
blurHorizontal(canvas, scratch, std::min(radius, std::max(1, width - 1)));
|
|
std::swap(canvas, scratch);
|
|
}
|
|
if (direction != "horizontal") {
|
|
blurVertical(canvas, scratch, std::min(radius, std::max(1, height - 1)));
|
|
std::swap(canvas, scratch);
|
|
}
|
|
}
|
|
}
|
|
|
|
} // namespace effector
|