I am trying to use the `cairo_region_create_rectan...

# kotlin-native

[napperley]

I am trying to use the cairo_region_create_rectangles function ( https://www.cairographics.org/manual/cairo-Regions.html#cairo-region-create-rectangles ) from the Cairo library, but the function is after CValuesRef<cairo_rectangle_int_t>? as the first parameter and I don't know how to provide a CValuesRef that contains multiple struct pointers. Below is the code that fails to compile (the values variable doesn't match what the cairo_region_create_rectangles function is expecting):

// ...
fun createWithMultipleRectangles(vararg rectangles: IntRectangle): Region {
            val tmpArr = rectangles.map { it.cairoRect.ptr }.toTypedArray()
            val values = cValuesOf(*tmpArr)
            return Region(cairo_region_create_rectangles(values, rectangles.size))
        }
// ...

[napperley]

One way to do it is to do the following:

fun createWithMultipleRectangles(vararg rectangles: IntRectangle): Region = memScoped {
            val tmpArr = allocArray<_cairo_rectangle_int>(rectangles.size)
            rectangles.forEachIndexed { pos, item ->
                tmpArr[pos].height = item.height
                tmpArr[pos].width = item.width
                tmpArr[pos].x = item.xPos
                tmpArr[pos].y = item.yPos
            }
            return Region(cairo_region_create_rectangles(tmpArr, rectangles.size))
        }

Although this works (no compile errors) rectangles is deep copied, which isn't what I want to achieve. I want to pass through the _cairo_rectangle_int pointers to the function as the first parameter.