C++: implement creation of image from raw data

Issue #616

api/cpp/include/slint_image.h

@@ -11,6 +11,9 @@
 
 namespace slint {
 
+using cbindgen_private::types::Rgb8Pixel;
+using cbindgen_private::types::Rgba8Pixel;
+
 /// An image type that can be displayed by the Image element
 struct Image
 {
@@ -25,13 +28,33 @@ public:
         return img;
     }
 
-    /*
+    /// Construct an image from a vector of RGB pixel.
-    static Image load_from_argb(int width, int height, const SharedVector<uint32_t> &data) {
+    /// The size of the vector \a data should be \a width * \a height
+    static Image from_raw_data(unsigned int width, unsigned int height,
+                               const SharedVector<Rgb8Pixel> &data)
+    {
         Image img;
-        img.data = Data::EmbeddedRgbaImage(width, height, data);
+        img.data = Data::ImageInner_EmbeddedImage(
+                cbindgen_private::types::ImageCacheKey::Invalid(),
+                cbindgen_private::types::SharedImageBuffer::RGB8(
+                        cbindgen_private::types::SharedPixelBuffer<Rgb8Pixel> {
+                                .width = width, .height = height, .data = data }));
+        return img;
+    }
+
+    /// Construct an image from a vector of RGBA pixels.
+    /// The size of the vector \a data should be \a width * \a height
+    static Image from_raw_data(unsigned int width, unsigned int height,
+                               const SharedVector<Rgba8Pixel> &data)
+    {
+        Image img;
+        img.data = Data::ImageInner_EmbeddedImage(
+                cbindgen_private::types::ImageCacheKey::Invalid(),
+                cbindgen_private::types::SharedImageBuffer::RGBA8(
+                        cbindgen_private::types::SharedPixelBuffer<Rgba8Pixel> {
+                                .width = width, .height = height, .data = data }));
         return img;
     }
-    */
 
     /// Returns the size of the Image in pixels.
     Size<unsigned int> size() const { return cbindgen_private::types::slint_image_size(&data); }

api/cpp/tests/datastructures.cpp

@@ -172,6 +172,23 @@ TEST_CASE("Image")
         REQUIRE(actual_path.has_value());
         REQUIRE(*actual_path == SOURCE_DIR "/../../../logo/slint-logo-square-light-128x128.png");
     }
+
+    img = Image::from_raw_data(0, 0, SharedVector<Rgba8Pixel> {});
+    {
+        auto size = img.size();
+        REQUIRE(size.width == 0);
+        REQUIRE(size.height == 0);
+        REQUIRE(!img.path().has_value());
+    }
+    auto red = Rgb8Pixel { 0xff, 0, 0 };
+    auto blu = Rgb8Pixel { 0, 0, 0xff };
+    img = Image::from_raw_data(3, 2, SharedVector<Rgb8Pixel> { red, red, blu, red, blu, blu });
+    {
+        auto size = img.size();
+        REQUIRE(size.width == 3);
+        REQUIRE(size.height == 2);
+        REQUIRE(!img.path().has_value());
+    }
 }
 
 TEST_CASE("SharedVector")

internal/core/graphics/image.rs

@@ -670,7 +670,8 @@ pub(crate) mod ffi {
     use super::super::IntSize;
     use super::*;
 
-    /// Expand Rgb8Pixel so that cbindgen can see it. (is in fact rgb::RGB<u8>)
+    // Expand Rgb8Pixel so that cbindgen can see it. (is in fact rgb::RGB<u8>)
+    /// Represents a RGB pixel
     #[cfg(cbindgen)]
     #[repr(C)]
     struct Rgb8Pixel {
@@ -679,7 +680,8 @@ pub(crate) mod ffi {
         b: u8,
     }
 
-    /// Expand Rgba8Pixel so that cbindgen can see it. (is in fact rgb::RGBA<u8>)
+    // Expand Rgba8Pixel so that cbindgen can see it. (is in fact rgb::RGBA<u8>)
+    /// Represents a RGBA pixel
     #[cfg(cbindgen)]
     #[repr(C)]
     struct Rgba8Pixel {