Merge commit 'e0b7d30fd437292c88141fb08d60681870b86c6e' as 'subprojects/pixpat'

1 files changed, 72 insertions, 0 deletions

diff --git a/subprojects/pixpat/pixpat-native/src/io/mono_rgb.h b/subprojects/pixpat/pixpat-native/src/io/mono_rgb.h
new file mode 100644
index 0000000..f2f8206
--- /dev/null
+++ b/subprojects/pixpat/pixpat-native/src/io/mono_rgb.h
@@ -0,0 +1,72 @@
+#pragma once
+
+// Single-channel RGB formats (R8). Storage carries one R component;
+// MonoRGBSource synthesizes G=B=R on read so cross-color-kind ColorXfm
+// produces sensible Y from R alone. MonoRGBSink encodes R and ignores
+// G/B/A (and zeroes any X padding). Symmetric to GraySource/GraySink
+// (io/gray.h) but for ColorKind::RGB on C::R.
+
+#include <array>
+
+#include "../layout.h"
+#include "detail.h"
+
+namespace pixpat
+{
+
+template <typename L>
+struct MonoRGBSource {
+	using Layout = L;
+	using Pixel  = RGB16;
+
+	static_assert(L::kind == ColorKind::RGB);
+	static_assert(L::num_planes == 1);
+
+	using P = typename L::template plane<0>;
+	static constexpr size_t r_idx = P::template find_pos<C::R>();
+	static_assert(r_idx < P::num_comps);
+
+	static RGB16 read(const Buffer<1>& buf, size_t x, size_t y,
+	                  [[maybe_unused]] size_t W,
+	                  [[maybe_unused]] size_t H) noexcept
+	{
+		const uint8_t* p = buf.data[0] + y * buf.stride[0]
+		                   + x * P::bytes_per_pixel;
+		const auto vals = P::unpack(detail::load_word<P>(p));
+		const uint16_t r = detail::decode_norm(P::comps[r_idx].bits, vals[r_idx]);
+		return RGB16{ r, r, r, uint16_t(0) };
+	}
+};
+
+template <typename L>
+struct MonoRGBSink {
+	using Layout = L;
+	using Pixel  = RGB16;
+
+	static_assert(L::kind == ColorKind::RGB);
+	static_assert(L::num_planes == 1);
+
+	using P = typename L::template plane<0>;
+	static constexpr size_t r_idx = P::template find_pos<C::R>();
+	static constexpr size_t x_idx = P::template find_pos<C::X>();
+	static constexpr bool has_x = (x_idx < P::num_comps);
+	static_assert(r_idx < P::num_comps);
+
+	static constexpr size_t block_h = 1;
+	static constexpr size_t block_w = 1;
+
+	static void write_block(Buffer<1>& buf, size_t bx, size_t by,
+	                        const RGB16 (&block)[1][1]) noexcept
+	{
+		std::array<uint16_t, P::num_comps> v{};
+		v[r_idx] = detail::encode_norm(P::comps[r_idx].bits, block[0][0].r);
+		if constexpr (has_x)
+			v[x_idx] = 0;
+
+		uint8_t* p = buf.data[0] + by * buf.stride[0]
+		             + bx * P::bytes_per_pixel;
+		detail::store_word<P>(p, P::pack(v));
+	}
+};
+
+} // namespace pixpat