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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.
+
+InPlace upscaling works on a single array and assumes that the values to work on have already
+been interspersed into the array to the cell boundaries.
+Specifically, a_Array[x * a_AnchorStepX + y * a_AnchorStepY] contains the anchor value.
+
+Regular upscaling takes two arrays and "moves" the input from src to dst; src is expected packed.
+*/
+
+
+
+
+/**
+Linearly interpolates values in the array between the equidistant anchor points (upscales).
+Works in-place (input is already present at the correct output coords)
+*/
+template<typename TYPE> void LinearUpscale2DArrayInPlace(
+ 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;
+ }
+ }
+}
+
+
+
+
+
+/**
+Linearly interpolates values in the array between the equidistant anchor points (upscales).
+Works on two arrays, input is packed and output is to be completely constructed.
+*/
+template<typename TYPE> void LinearUpscale2DArray(
+ TYPE * a_Src, ///< Source array of size a_SrcSizeX x a_SrcSizeY
+ int a_SrcSizeX, int a_SrcSizeY, ///< Dimensions of the src array
+ TYPE * a_Dst, ///< Dest array, of size (a_SrcSizeX * a_UpscaleX + 1) x (a_SrcSizeY * a_UpscaleY + 1)
+ int a_UpscaleX, int a_UpscaleY ///< Upscale factor for each direction
+)
+{
+ // For optimization reasons, we're storing the upscaling ratios in a fixed-size arrays of these sizes
+ // Feel free to enlarge them if needed, but keep in mind that they're on the stack
+ const int MAX_UPSCALE_X = 128;
+ const int MAX_UPSCALE_Y = 128;
+
+ ASSERT(a_Src != NULL);
+ ASSERT(a_Dst != NULL);
+ ASSERT(a_SrcSizeX > 0);
+ ASSERT(a_SrcSizeY > 0);
+ ASSERT(a_UpscaleX > 0);
+ ASSERT(a_UpscaleY > 0);
+ ASSERT(a_UpscaleX <= MAX_UPSCALE_X);
+ ASSERT(a_UpscaleY <= MAX_UPSCALE_Y);
+
+ // Pre-calculate the upscaling ratios:
+ TYPE RatioX[MAX_UPSCALE_X];
+ TYPE RatioY[MAX_UPSCALE_Y];
+ for (int x = 0; x <= a_UpscaleX; x++)
+ {
+ RatioX[x] = (TYPE)x / a_UpscaleX;
+ }
+ for (int y = 0; y <= a_UpscaleY; y++)
+ {
+ RatioY[y] = (TYPE)y / a_UpscaleY;
+ }
+
+ // Interpolate each XY cell:
+ int DstSizeX = (a_SrcSizeX - 1) * a_UpscaleX + 1;
+ int DstSizeY = (a_SrcSizeY - 1) * a_UpscaleY + 1;
+ for (int y = 0; y < (a_SrcSizeY - 1); y++)
+ {
+ int DstY = y * a_UpscaleY;
+ int idx = y * a_SrcSizeX;
+ for (int x = 0; x < (a_SrcSizeX - 1); x++, idx++)
+ {
+ int DstX = x * a_UpscaleX;
+ TYPE LoXLoY = a_Src[idx];
+ TYPE LoXHiY = a_Src[idx + a_SrcSizeX];
+ TYPE HiXLoY = a_Src[idx + 1];
+ TYPE HiXHiY = a_Src[idx + 1 + a_SrcSizeX];
+ for (int CellY = 0; CellY <= a_UpscaleY; CellY++)
+ {
+ int DestIdx = (DstY + CellY) * DstSizeX + DstX;
+ ASSERT(DestIdx + a_UpscaleX < DstSizeX * DstSizeY);
+ TYPE LoXInY = LoXLoY + (LoXHiY - LoXLoY) * RatioY[CellY];
+ TYPE HiXInY = HiXLoY + (HiXHiY - HiXLoY) * RatioY[CellY];
+ for (int CellX = 0; CellX <= a_UpscaleX; CellX++, DestIdx++)
+ {
+ a_Dst[DestIdx] = LoXInY + (HiXInY - LoXInY) * RatioX[CellX];
+ }
+ } // for CellY
+ } // for x
+ } // for y
+}
+
+
+
+
+
+/**
+Linearly interpolates values in the array between the equidistant anchor points (upscales).
+Works on two arrays, input is packed and output is to be completely constructed.
+*/
+template<typename TYPE> void LinearUpscale3DArray(
+ TYPE * a_Src, ///< Source array of size a_SrcSizeX x a_SrcSizeY x a_SrcSizeZ
+ int a_SrcSizeX, int a_SrcSizeY, int a_SrcSizeZ, ///< Dimensions of the src array
+ TYPE * a_Dst, ///< Dest array, of size (a_SrcSizeX * a_UpscaleX + 1) x (a_SrcSizeY * a_UpscaleY + 1) x (a_SrcSizeZ * a_UpscaleZ + 1)
+ int a_UpscaleX, int a_UpscaleY, int a_UpscaleZ ///< Upscale factor for each direction
+)
+{
+ // For optimization reasons, we're storing the upscaling ratios in a fixed-size arrays of these sizes
+ // Feel free to enlarge them if needed, but keep in mind that they're on the stack
+ const int MAX_UPSCALE_X = 128;
+ const int MAX_UPSCALE_Y = 128;
+ const int MAX_UPSCALE_Z = 128;
+
+ ASSERT(a_Src != NULL);
+ ASSERT(a_Dst != NULL);
+ ASSERT(a_SrcSizeX > 0);
+ ASSERT(a_SrcSizeY > 0);
+ ASSERT(a_SrcSizeZ > 0);
+ ASSERT(a_UpscaleX > 0);
+ ASSERT(a_UpscaleY > 0);
+ ASSERT(a_UpscaleZ > 0);
+ ASSERT(a_UpscaleX <= MAX_UPSCALE_X);
+ ASSERT(a_UpscaleY <= MAX_UPSCALE_Y);
+ ASSERT(a_UpscaleZ <= MAX_UPSCALE_Z);
+
+ // Pre-calculate the upscaling ratios:
+ TYPE RatioX[MAX_UPSCALE_X];
+ TYPE RatioY[MAX_UPSCALE_Y];
+ TYPE RatioZ[MAX_UPSCALE_Z];
+ for (int x = 0; x <= a_UpscaleX; x++)
+ {
+ RatioX[x] = (TYPE)x / a_UpscaleX;
+ }
+ for (int y = 0; y <= a_UpscaleY; y++)
+ {
+ RatioY[y] = (TYPE)y / a_UpscaleY;
+ }
+ for (int z = 0; z <= a_UpscaleZ; z++)
+ {
+ RatioZ[z] = (TYPE)z / a_UpscaleZ;
+ }
+
+ // Interpolate each XYZ cell:
+ int DstSizeX = (a_SrcSizeX - 1) * a_UpscaleX + 1;
+ int DstSizeY = (a_SrcSizeY - 1) * a_UpscaleY + 1;
+ int DstSizeZ = (a_SrcSizeZ - 1) * a_UpscaleZ + 1;
+ for (int z = 0; z < (a_SrcSizeZ - 1); z++)
+ {
+ int DstZ = z * a_UpscaleZ;
+ for (int y = 0; y < (a_SrcSizeY - 1); y++)
+ {
+ int DstY = y * a_UpscaleY;
+ int idx = y * a_SrcSizeX + z * a_SrcSizeX * a_SrcSizeY;
+ for (int x = 0; x < (a_SrcSizeX - 1); x++, idx++)
+ {
+ int DstX = x * a_UpscaleX;
+ TYPE LoXLoYLoZ = a_Src[idx];
+ TYPE LoXLoYHiZ = a_Src[idx + a_SrcSizeX * a_SrcSizeY];
+ TYPE LoXHiYLoZ = a_Src[idx + a_SrcSizeX];
+ TYPE LoXHiYHiZ = a_Src[idx + a_SrcSizeX + a_SrcSizeX * a_SrcSizeY];
+ TYPE HiXLoYLoZ = a_Src[idx + 1];
+ TYPE HiXLoYHiZ = a_Src[idx + 1 + a_SrcSizeX * a_SrcSizeY];
+ TYPE HiXHiYLoZ = a_Src[idx + 1 + a_SrcSizeX];
+ TYPE HiXHiYHiZ = a_Src[idx + 1 + a_SrcSizeX + a_SrcSizeX * a_SrcSizeY];
+ for (int CellZ = 0; CellZ <= a_UpscaleZ; CellZ++)
+ {
+ TYPE LoXLoYInZ = LoXLoYLoZ + (LoXLoYHiZ - LoXLoYLoZ) * RatioZ[CellZ];
+ TYPE LoXHiYInZ = LoXHiYLoZ + (LoXHiYHiZ - LoXHiYLoZ) * RatioZ[CellZ];
+ TYPE HiXLoYInZ = HiXLoYLoZ + (HiXLoYHiZ - HiXLoYLoZ) * RatioZ[CellZ];
+ TYPE HiXHiYInZ = HiXHiYLoZ + (HiXHiYHiZ - HiXHiYLoZ) * RatioZ[CellZ];
+ for (int CellY = 0; CellY <= a_UpscaleY; CellY++)
+ {
+ int DestIdx = (DstZ + CellZ) * DstSizeX * DstSizeY + (DstY + CellY) * DstSizeX + DstX;
+ ASSERT(DestIdx + a_UpscaleX < DstSizeX * DstSizeY * DstSizeZ);
+ TYPE LoXInY = LoXLoYInZ + (LoXHiYInZ - LoXLoYInZ) * RatioY[CellY];
+ TYPE HiXInY = HiXLoYInZ + (HiXHiYInZ - HiXLoYInZ) * RatioY[CellY];
+ for (int CellX = 0; CellX <= a_UpscaleX; CellX++, DestIdx++)
+ {
+ a_Dst[DestIdx] = LoXInY + (HiXInY - LoXInY) * RatioX[CellX];
+ }
+ } // for CellY
+ } // for CellZ
+ } // for x
+ } // for y
+ } // for z
+}
+
+
+
+
+
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