#include "render/IConstantMapping.h"

IConstantMapping::IConstantMapping()
	:lastSlotId(0)
{
}
IConstantMapping::~IConstantMapping()
{
}
uint32 IConstantMapping::GetAlignedSize()
{
	return (lastSlotId + 1) * HLSL_CONSTANT_SIZE * (mapping.size() > 0 ? 1 : 0);
}
void IConstantMapping::InsertConstant(const String& name, uint32 numRows, uint32 numCols)
{
	if(!numRows || !numCols) return;

	if(numRows == 1)
	{
		//try to insert variable in @white spaces@
		if(spaces.size() > 0)
		{
			for(ConstantCollectionItr it = spaces.begin(); it != spaces.end(); ++it)
			{
				if((*it).ColumnCount <= numCols) //found suitable white space! Fill it ^^
				{
					mapping.push_back(IConstantMappingData((*it).SlotID, (*it).SlotOffset, 1, numCols));
					(*it).SlotOffset += numCols;
					(*it).ColumnCount -= numCols;
					if((*it).ColumnCount <= 0)
						spaces.erase(it);
					return;
				}
			}
		}
		mapping.push_back(IConstantMappingData(lastSlotId++, 0, 1, numCols));
		if(numCols < 4)
			spaces.push_back(IConstantMappingData(lastSlotId, numCols, 1, 4 - numCols));
	}
	else
	{
		mapping.push_back(IConstantMappingData(lastSlotId, 0, numRows, numCols));
		lastSlotId+=numRows;
	}
}