draw_view.hpp

#ifndef PASTELGFX_DRAW_VIEW_HPP
#define PASTELGFX_DRAW_VIEW_HPP

#include "pastel/geometry/intersect/intersect_alignedbox_alignedbox.h"

#include "pastel/gfx/drawing/draw_view.h"
#include "pastel/gfx/color/colormixer/assign_colormixer.h"

#include "pastel/sys/view/view_visit.h"
#include "pastel/sys/view/subview.h"

namespace Pastel
{

    namespace DrawView_
    {

        template <typename ColorMixer>
        class Visitor
        {
        public:
            explicit Visitor(
                const ColorMixer& colorMixer)
                : colorMixer_(colorMixer)
            {
            }

            template <typename Texture, typename Image>
            void operator()(
                const Texture& texture,
                Image& image) const
            {
                image = colorMixer_(image, texture);
            }

        private:
            const ColorMixer& colorMixer_;
        };

    }

    template <integer N,
        typename Texture_Element, typename Texture_View,
        typename Image_Element, typename Image_View,
        typename ColorMixer>
    void drawView(
        const ConstView<N, Texture_Element, Texture_View>& texture,
        const Vector<integer, N>& position,
        const View<N, Image_Element, Image_View>& image,
        const ColorMixer& colorMixer)
    {
        AlignedBox<integer, N> textureBox(
            position, position + texture.extent());
        AlignedBox<integer, N> imageBox(
            Vector<integer, N>(0), image.extent());

        AlignedBox<integer, N> clippedTextureBox;
        if (!intersect(textureBox, imageBox, clippedTextureBox))
        {
            return;
        }

        DrawView_::Visitor<ColorMixer> visitor(colorMixer);

        visit(constSubView(texture, clippedTextureBox - position),
            subView(image, clippedTextureBox), visitor);
    }

    template <integer N,
        typename Texture_Element, typename Texture_View,
        typename Image_Element, typename Image_View>
    void drawView(
        const ConstView<N, Texture_Element, Texture_View>& texture,
        const Vector<integer, N>& position,
        const View<N, Image_Element, Image_View>& image)
    {
        drawView(texture, position, image, assignColorMixer<Image_Element>());
    }

}

#endif