# split pd-maths into pd-core and pd-image (0.2.3)

source/image/img_blur.cpp

@@ -0,0 +1,88 @@
+/*
+MIT License
+
+Copyright (c) 2024 - 2025 tobid7
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+ */
+
+#include <cstring>
+#include <memory>
+#include <pd/image/img_blur.hpp>
+#include <pd/image/img_convert.hpp>
+
+namespace PD {
+namespace ImgBlur {
+std::vector<float> GaussianKernel(int r, float si) {
+  /// Define radius as r to be shorter
+  int size = 2 * r + 1;
+  std::vector<float> kernel(size);
+  float sum = 0.0f;
+
+  for (int i = -r; i <= r; i++) {
+    kernel[i + r] = exp(-0.5f * (i * i) / (si * si));
+    sum += kernel[i + r];
+  }
+
+  for (int i = 0; i < size; i++) {
+    kernel[i] /= sum;
+  }
+  return kernel;
+}
+void GaussianBlur(std::vector<u8> &buf, int w, int h, float radius, float si,
+                  std::function<int(int, int, int)> idxfn) {
+  GaussianBlur(buf.data(), w, h, 4, radius, si, idxfn);
+}
+
+void GaussianBlur(void *buf, int w, int h, int bpp, float radius, float si,
+                  std::function<int(int, int, int)> idxfn) {
+  if (bpp != 4 && bpp != 3) {
+    return;
+  }
+  std::vector<float> kernel = GaussianKernel(radius, si);
+  int hks = kernel.size() / 2;
+  int end = w * h * bpp;
+  std::vector<unsigned char> res((u8 *)buf, ((u8 *)buf) + end);
+  ImgConvert::Reverse32(res, w, h);
+  for (int y = 0; y < h; y++) {
+    for (int x = 0; x < w; x++) {
+      float r = 0.0f, g = 0.0f, b = 0.0f;
+      for (int ky = -hks; ky <= hks; ky++) {
+        for (int kx = -hks; kx <= hks; kx++) {
+          int xoff = std::min(std::max(x + kx, 0), w - 1);
+          int yoff = std::min(std::max(y + ky, 0), h - 1);
+          int idx = idxfn(xoff, yoff, w) * 4;
+
+          float weight = kernel[ky + hks] * kernel[kx + hks];
+          r += ((u8 *)buf)[idx] * weight;
+          g += ((u8 *)buf)[idx + 1] * weight;
+          b += ((u8 *)buf)[idx + 2] * weight;
+        }
+      }
+      int idx = idxfn(x, y, w) * bpp;
+      res[idx] = std::min(std::max(int(r), 0), 255);
+      res[idx + 1] = std::min(std::max(int(g), 0), 255);
+      res[idx + 2] = std::min(std::max(int(b), 0), 255);
+    }
+  }
+  ImgConvert::Reverse32(res, w, h);
+  std::memcpy(buf, res.data(), res.size());
+}
+}  // namespace ImgBlur
+}  // namespace PD

source/image/img_convert.cpp

@@ -0,0 +1,54 @@
+/*
+MIT License
+Copyright (c) 2024 - 2025 René Amthor (tobid7)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+ */
+
+#include <pd/image/img_convert.hpp>
+
+namespace PD::ImgConvert {
+void RGB24toRGBA32(std::vector<u8> &out, const std::vector<u8> &in,
+                   const int &w, const int &h) {
+  // Converts RGB24 to RGBA32
+  for (int y = 0; y < h; y++) {
+    for (int x = 0; x < w; x++) {
+      int src = (y * w + x) * 3;
+      int dst = (y * w + x) * 4;
+      out[dst + 0] = in[src + 0];
+      out[dst + 1] = in[src + 1];
+      out[dst + 2] = in[src + 2];
+      out[dst + 3] = 255;
+    }
+  }
+}
+void Reverse32(std::vector<u8> &buf, const int &w, const int &h) {
+  for (int x = 0; x < w; x++) {
+    for (int y = 0; y < h; y++) {
+      int i = y * w + x;
+      u8 t0 = buf[i + 0];
+      u8 t1 = buf[i + 1];
+      buf[i + 0] = buf[i + 3];
+      buf[i + 1] = buf[i + 2];
+      buf[i + 3] = t0;
+      buf[i + 2] = t1;
+    }
+  }
+}
+}  // namespace PD::ImgConvert