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+
+// LinearUpscale.h
+
+// Declares the functions for linearly upscaling arrays
+
+/*
+Upscaling means that the array is divided into same-size "cells", and each cell is
+linearly interpolated between its corners. The array's dimensions are therefore
+1 + CellSize * NumCells, for each direction.
+
+Upscaling is more efficient than linear interpolation, because the cell sizes are integral
+and therefore the cells' boundaries are on the array points.
+
+However, upscaling usually requires generating the "1 +" in each direction.
+
+Upscaling is implemented in templates, so that it's compatible with multiple datatypes.
+Therefore, there is no cpp file.
+*/
+
+
+
+
+/// Linearly interpolates values in the array between the equidistant anchor points; universal data type
+template<typename TYPE> void ArrayLinearUpscale2D(
+ TYPE * a_Array,
+ int a_SizeX, int a_SizeY, // Dimensions of the array
+ int a_AnchorStepX, int a_AnchorStepY // Distances between the anchor points in each direction
+)
+{
+ // First interpolate columns where the anchor points are:
+ int LastYCell = a_SizeY - a_AnchorStepY;
+ for (int y = 0; y < LastYCell; y += a_AnchorStepY)
+ {
+ int Idx = a_SizeX * y;
+ for (int x = 0; x < a_SizeX; x += a_AnchorStepX)
+ {
+ TYPE StartValue = a_Array[Idx];
+ TYPE EndValue = a_Array[Idx + a_SizeX * a_AnchorStepY];
+ TYPE Diff = EndValue - StartValue;
+ for (int CellY = 1; CellY < a_AnchorStepY; CellY++)
+ {
+ a_Array[Idx + a_SizeX * CellY] = StartValue + Diff * CellY / a_AnchorStepY;
+ } // for CellY
+ Idx += a_AnchorStepX;
+ } // for x
+ } // for y
+
+ // Now interpolate in rows, each row has values in the anchor columns
+ int LastXCell = a_SizeX - a_AnchorStepX;
+ for (int y = 0; y < a_SizeY; y++)
+ {
+ int Idx = a_SizeX * y;
+ for (int x = 0; x < LastXCell; x += a_AnchorStepX)
+ {
+ TYPE StartValue = a_Array[Idx];
+ TYPE EndValue = a_Array[Idx + a_AnchorStepX];
+ TYPE Diff = EndValue - StartValue;
+ for (int CellX = 1; CellX < a_AnchorStepX; CellX++)
+ {
+ a_Array[Idx + CellX] = StartValue + CellX * Diff / a_AnchorStepX;
+ } // for CellY
+ Idx += a_AnchorStepX;
+ }
+ }
+}
+
+
+
+
+