C++ Rgb565Pixel

api/cpp/include/slint_platform.h

@@ -278,6 +278,49 @@ private:
     PhysicalRegion(cbindgen_private::types::IntRect inner) : inner(inner) { }
 };
 
+/// A 16bit pixel that has 5 red bits, 6 green bits and 5 blue bits
+struct Rgb565Pixel
+{
+    /// The red component, encoded in 5 bits.
+    uint16_t r : 5;
+    /// The green component, encoded in 6 bits.
+    uint16_t g : 6;
+    /// The blue component, encoded in 5 bits.
+    uint16_t b : 5;
+
+    /// Default constructor.
+    constexpr Rgb565Pixel() : r(0), g(0), b(0) { }
+
+    /// \brief Constructor that constructs from an Rgb8Pixel.
+    explicit constexpr Rgb565Pixel(const Rgb8Pixel &pixel)
+        : r(pixel.r >> 3), g(pixel.g >> 2), b(pixel.b >> 3)
+    {
+    }
+
+    /// \brief Get the red component as an 8-bit value.
+    ///
+    /// The bits are shifted so that the result is between 0 and 255.
+    /// \return The red component as an 8-bit value.
+    constexpr uint8_t red() const { return (r << 3) | (r >> 2); }
+
+    /// \brief Get the green component as an 8-bit value.
+    ///
+    /// The bits are shifted so that the result is between 0 and 255.
+    /// \return The green component as an 8-bit value.
+    constexpr uint8_t green() const { return (g << 2) | (g >> 4); }
+
+    /// \brief Get the blue component as an 8-bit value.
+    ///
+    /// The bits are shifted so that the result is between 0 and 255.
+    /// \return The blue component as an 8-bit value.
+    constexpr uint8_t blue() const { return (b << 3) | (b >> 2); }
+
+    /// \brief Convert to Rgb8Pixel.
+    constexpr operator Rgb8Pixel() const { return { red(), green(), blue() }; }
+
+    friend bool operator==(const Rgb565Pixel &, const Rgb565Pixel &) = default;
+};
+
 /// Slint's software renderer.
 ///
 /// To be used as a template parameter of the WindowAdapter.
@@ -322,11 +365,12 @@ public:
     ///
     /// The stride is the amount of pixels between two lines in the buffer.
     /// It is must be at least as large as the width of the window.
-    PhysicalRegion render(const Window &window, std::span<uint16_t> buffer,
+    PhysicalRegion render(const Window &window, std::span<Rgb565Pixel> buffer,
                           std::size_t pixel_stride) const
     {
         auto r = cbindgen_private::slint_software_renderer_render_rgb565(
-                inner, &window.window_handle().inner, buffer.data(), buffer.size(), pixel_stride);
+                inner, &window.window_handle().inner, reinterpret_cast<uint16_t *>(buffer.data()),
+                buffer.size(), pixel_stride);
         return PhysicalRegion { r };
     }
 };