inline float_type interpolation_wrapper(float_type * buffer, index_type index)
{
/* the compiler will optimize this */
switch (interpolation)
{
case 0: // no interpolation
{
std::size_t table_index = std::size_t(std::floor(index));
return buffer[table_index];
}
case 1: // linear interpolation
{
return linearinterp(buffer, index);
}
case 3: // cubic interpolation (use heremite interpolation)
{
return cubicinterp(buffer, index);
}
default:
{
const uint interpolation_points = interpolation + 1;
std::size_t offset = std::size_t(std::floor(index));
return interpolate<interpolation_points>(buffer + offset, index - offset);
}
}
}
inline value_type linearinterp(value_type * buffer, index_type index)
{
std::size_t left_index = std::size_t(std::floor(index));
std::size_t right_index = left_index + 1;
index_type frac_pos = index - left_index;
return linearinterp(frac_pos, buffer[left_index], buffer[right_index]);
}
VOID DrawLerpFunction(HDC hDC,int startX,int endX,int startY,int endY,int elements,double power)
{
MoveToEx(hDC,startX,startY,NULL);
LineTo(hDC,endX,startY);
for(unsigned int i = startX; i <= endX; i += 8)
{
MoveToEx(hDC,i,startY + 2,NULL);
LineTo(hDC,i,startY - 3);
}
MoveToEx(hDC,startX,startY,NULL);
LineTo(hDC,startX,endY);
for(unsigned int i = endY; i <= startY; i += 8)
{
MoveToEx(hDC,startX + 2,i,NULL);
LineTo(hDC,startX - 3,i);
}
WCHAR text[256];
wsprintf(text,L"Linear (Power %g)",power);
RECT rect = {startX+10,endY,0,0};
DrawText(hDC,text,-1,&rect,DT_NOCLIP);
HGDIOBJ old = SelectObject(hDC,CreatePen(PS_DOT,1,RGB(192,192,192)));
for(int i = 0; i < elements; i += 16)
{
MoveToEx(hDC,double(startX) + double(endX - startX) / double(elements) * double(i),startY,NULL);
LineTo(hDC,double(startX) + double(endX - startX) / double(elements) * double(i),double(startY) + double(endY - startY) * linearinterp(0.0,1.0,double(i)/double(elements),power));
}
DeleteObject(SelectObject(hDC,old));
for(int i = 0; i < elements; ++i)
{
MoveToEx(hDC,double(startX) + double(endX - startX) / double(elements) * double(i),double(startY) + double(endY - startY) * linearinterp(0.0,1.0,double(i)/double(elements),power),NULL);
LineTo(hDC,double(startX) + double(endX - startX) / double(elements) * double(i+1),double(startY) + double(endY - startY) * linearinterp(0.0,1.0,double(i+1)/double(elements),power));
}
}
