#include<hgl/graph/vulkan/VKDevice.h>
#include<hgl/graph/vulkan/VKPhysicalDevice.h>
#include<hgl/graph/TileData.h>

namespace
{
	using namespace hgl;

    void AnalyseSize(uint &fw,uint &fh,const uint w,const uint h,const uint count,const uint32_t max_texture_size)
	{
		int total,tw,th,t;

		fw=fh=0;

		tw=max_texture_size;
		while(tw>=w)
		{
			th=max_texture_size;
			while(th>=h)
			{
				t=(tw/w)*(th/h);

				if(!fw)
				{
					fw=tw;
					fh=th;

					total=t;
				}
				else
				{
					if(t==count)
					{
						//正好，就要这么大的

						fw=tw;
						fh=th;

						return;
					}
					else
					if(t>count)                //要比要求的最大值大
					{
						if(t<total)            //找到最接近最大值的
						{
							//比现在选中的更节省
							fw=tw;
							fh=th;

							total=t;
						}
					}
				}

				th>>=1;
			}

			tw>>=1;
		}
	}//void AnalyseSize
}//namespace

VK_NAMESPACE_BEGIN
TileData *Device::CreateTileData(const VkFormat format,const uint width,const uint height,const uint count)
{
    if(!CheckVulkanFormat(format))
        return(nullptr);

    if(width<=0||height<=0||count<=0)
        return(nullptr);

    const uint32_t max_2d_texture=attr->physical_device->GetMaxImage2D();

    uint tex_width,tex_height;

	AnalyseSize(tex_width,tex_height,width,height,count,max_2d_texture);

	const VulkanFormat *vf=GetVulkanFormat(format);

	if(!vf)return(nullptr);

	Texture2D *tex=nullptr;

	if(vf->color>VulkanDataType::NONE
	 &&vf->color<VulkanDataType::END)
	{
		tex=CreateTexture2DColor(format,tex_width,tex_height);
	}
	else
	if(vf->depth>VulkanDataType::NONE
	 &&vf->depth<VulkanDataType::END)
	{
		tex=CreateTexture2DDepth(format,tex_width,tex_height);
	}
	else
		return(nullptr);

	return(new TileData(this,tex,width,height));
}
VK_NAMESPACE_END