initial commit

libraries/FastLED/src/fl/splat.cpp

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+
+#include "fl/tile2x2.h"
+#include "fl/splat.h"
+#include "fl/math.h"
+
+namespace fl {
+
+static u8 to_uint8(float f) {
+    // convert to [0..255] range
+    u8 i = static_cast<u8>(f * 255.0f + .5f);
+    return MIN(i, 255);
+}
+
+Tile2x2_u8 splat(vec2f xy) {
+    // 1) collect values.
+    float x = xy.x;
+    float y = xy.y;
+
+    // 2) integer cell indices
+    i16 cx = static_cast<i16>(floorf(x));
+    i16 cy = static_cast<i16>(floorf(y));
+
+    // 3) fractional offsets in [0..1)
+    float fx = x - cx;
+    float fy = y - cy;
+
+    // 4) bilinear weights
+    float w_ll = (1 - fx) * (1 - fy); // lower‑left
+    float w_lr = fx * (1 - fy);       // lower‑right
+    float w_ul = (1 - fx) * fy;       // upper‑left
+    float w_ur = fx * fy;             // upper‑right
+
+    // 5) build Tile2x2_u8 anchored at (cx,cy)
+    Tile2x2_u8 out(vec2<u16>(cx, cy));
+    out.lower_left() = to_uint8(w_ll);
+    out.lower_right() = to_uint8(w_lr);
+    out.upper_left() = to_uint8(w_ul);
+    out.upper_right() = to_uint8(w_ur);
+
+    return out;
+}
+
+}  // namespace