move image scaling functions to their own unit, as -O2

1 files changed, 98 insertions, 0 deletions

diff --git a/source/core/StarImageScaling.cpp b/source/core/StarImageScaling.cpp
new file mode 100644
index 0000000..96837aa
--- /dev/null
+++ b/source/core/StarImageScaling.cpp
@@ -0,0 +1,98 @@
+#include "StarImage.hpp"
+#include "StarImageScaling.hpp"
+#include "StarInterpolation.hpp"
+
+namespace Star {
+
+Image scaleNearest(Image const& srcImage, Vec2F const& scale) {
+  Vec2U srcSize = srcImage.size();
+  Vec2U destSize = Vec2U::round(vmult(Vec2F(srcSize), scale));
+  destSize[0] = max(destSize[0], 1u);
+  destSize[1] = max(destSize[1], 1u);
+
+  Image destImage(destSize, srcImage.pixelFormat());
+
+  for (unsigned y = 0; y < destSize[1]; ++y) {
+    for (unsigned x = 0; x < destSize[0]; ++x)
+      destImage.set({x, y}, srcImage.clamp(Vec2I::round(vdiv(Vec2F(x, y), scale))));
+  }
+  return destImage;
+}
+
+Image scaleBilinear(Image const& srcImage, Vec2F const& scale) {
+  Vec2U srcSize = srcImage.size();
+  Vec2U destSize = Vec2U::round(vmult(Vec2F(srcSize), scale));
+  destSize[0] = max(destSize[0], 1u);
+  destSize[1] = max(destSize[1], 1u);
+
+  Image destImage(destSize, srcImage.pixelFormat());
+
+  for (unsigned y = 0; y < destSize[1]; ++y) {
+    for (unsigned x = 0; x < destSize[0]; ++x) {
+      auto pos = vdiv(Vec2F(x, y), scale);
+      auto ipart = Vec2I::floor(pos);
+      auto fpart = pos - Vec2F(ipart);
+
+      auto result = lerp(fpart[1], lerp(fpart[0], Vec4F(srcImage.clamp(ipart[0], ipart[1])), Vec4F(srcImage.clamp(ipart[0] + 1, ipart[1]))), lerp(fpart[0],
+            Vec4F(srcImage.clamp(ipart[0], ipart[1] + 1)), Vec4F(srcImage.clamp(ipart[0] + 1, ipart[1] + 1))));
+
+      destImage.set({x, y}, Vec4B(result));
+    }
+  }
+
+  return destImage;
+}
+
+Image scaleBicubic(Image const& srcImage, Vec2F const& scale) {
+  Vec2U srcSize = srcImage.size();
+  Vec2U destSize = Vec2U::round(vmult(Vec2F(srcSize), scale));
+  destSize[0] = max(destSize[0], 1u);
+  destSize[1] = max(destSize[1], 1u);
+
+  Image destImage(destSize, srcImage.pixelFormat());
+
+  for (unsigned y = 0; y < destSize[1]; ++y) {
+    for (unsigned x = 0; x < destSize[0]; ++x) {
+      auto pos = vdiv(Vec2F(x, y), scale);
+      auto ipart = Vec2I::floor(pos);
+      auto fpart = pos - Vec2F(ipart);
+
+      Vec4F a = cubic4(fpart[0],
+          Vec4F(srcImage.clamp(ipart[0], ipart[1])),
+          Vec4F(srcImage.clamp(ipart[0] + 1, ipart[1])),
+          Vec4F(srcImage.clamp(ipart[0] + 2, ipart[1])),
+          Vec4F(srcImage.clamp(ipart[0] + 3, ipart[1])));
+
+      Vec4F b = cubic4(fpart[0],
+          Vec4F(srcImage.clamp(ipart[0], ipart[1] + 1)),
+          Vec4F(srcImage.clamp(ipart[0] + 1, ipart[1] + 1)),
+          Vec4F(srcImage.clamp(ipart[0] + 2, ipart[1] + 1)),
+          Vec4F(srcImage.clamp(ipart[0] + 3, ipart[1] + 1)));
+
+      Vec4F c = cubic4(fpart[0],
+          Vec4F(srcImage.clamp(ipart[0], ipart[1] + 2)),
+          Vec4F(srcImage.clamp(ipart[0] + 1, ipart[1] + 2)),
+          Vec4F(srcImage.clamp(ipart[0] + 2, ipart[1] + 2)),
+          Vec4F(srcImage.clamp(ipart[0] + 3, ipart[1] + 2)));
+
+      Vec4F d = cubic4(fpart[0],
+          Vec4F(srcImage.clamp(ipart[0], ipart[1] + 3)),
+          Vec4F(srcImage.clamp(ipart[0] + 1, ipart[1] + 3)),
+          Vec4F(srcImage.clamp(ipart[0] + 2, ipart[1] + 3)),
+          Vec4F(srcImage.clamp(ipart[0] + 3, ipart[1] + 3)));
+
+      auto result = cubic4(fpart[1], a, b, c, d);
+
+      destImage.set({x, y}, Vec4B(
+          clamp(result[0], 0.0f, 255.0f),
+          clamp(result[1], 0.0f, 255.0f),
+          clamp(result[2], 0.0f, 255.0f),
+          clamp(result[3], 0.0f, 255.0f)
+        ));
+    }
+  }
+
+  return destImage;
+}
+
+}
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