#include <string.h>
#include <ui/Canvas.h>

namespace ui
{
    Canvas Canvas::create(u8* ptr, int width, int height)
    {
        return Canvas { .width = width, .height = height, .stride = width, .ptr = ptr };
    }

    Result<Canvas> Canvas::subcanvas(Point begin, int w, int h, bool clamp)
    {
        if (!clamp)
        {
            if (begin.x + w > width) return err(ERANGE);
            if (begin.y + h > height) return err(ERANGE);
        }
        else
        {
            if (begin.x + w > width) w = width - begin.x;
            if (begin.y + h > height) h = height - begin.y;
        }

        u8* p = ptr + begin.x * sizeof(Color) + (begin.y * sizeof(Color) * stride);

        return Canvas { .width = w, .height = h, .stride = stride, .ptr = p };
    }

    void Canvas::fill(Color color)
    {
        u8* p = ptr;
        for (int i = 0; i < height; i++)
        {
            u32* colorp = (u32*)p;
            for (int j = 0; j < width; j++)
            {
                *colorp = color.raw;
                colorp++;
            }
            p += stride * sizeof(Color);
        }
    }
}