WallyHackenslacker/Aerofoil
1
0
Fork 0
mirror of https://github.com/elasota/Aerofoil.git synced 2025-09-23 23:00:42 +00:00
Code Issues Projects Releases Wiki Activity

Implicit divide by 4 in ellipse plotter, disable debug asserts by default

Browse Source
This commit is contained in:
elasota
2020-01-22 01:48:02 -05:00
parent 06243e4d45
commit 27a1f89c15
2 changed files with 82 additions and 69 deletions
Download Patch File Download Diff File Expand all files Collapse all files

134
PortabilityLayer/EllipsePlotter.cpp
View File

@@ -24,9 +24,10 @@ namespace PortabilityLayer
, m_point(0, 0)
#if PL_DEBUG_ELLIPSE_PLOTTER
, m_2offsetFromCenter(0, 0)
, m_sqDistFromEdge(0)
#endif
, m_quadrant(Quadrant_PxPy)
, m_sqDistFromEdge(0)
, m_sqDistFromEdgeOver4RoundedUp(0)
{
}
@@ -54,12 +55,14 @@ namespace PortabilityLayer
const int64_t diameterSq = SquareInt64(m_diameters.m_x*m_diameters.m_y);
const int64_t sqDistX = SquareInt64(m_2offsetFromCenter.m_x*m_diameters.m_y);
const int64_t sqDistY = SquareInt64(m_2offsetFromCenter.m_y*m_diameters.m_x);
const int64_t xChangeCostDynamicFactor = static_cast<int64_t>(m_xChangeCostDynamicFactorOver4) * 4;
const int64_t yChangeCostDynamicFactor = static_cast<int64_t>(m_yChangeCostDynamicFactorOver4) * 4;
assert(m_sqDistFromEdge >= 0);
assert(sqDistX + sqDistY >= diameterSq);
assert(sqDistX + sqDistY - diameterSq == m_sqDistFromEdge);
assert(m_xChangeCostDynamicFactor == m_2offsetFromCenter.m_x * 4 * SquareInt32(m_diameters.m_y));
assert(m_yChangeCostDynamicFactor == m_2offsetFromCenter.m_y * 4 * SquareInt32(m_diameters.m_x));
assert(xChangeCostDynamicFactor == m_2offsetFromCenter.m_x * 4 * SquareInt32(m_diameters.m_y));
assert(yChangeCostDynamicFactor == m_2offsetFromCenter.m_y * 4 * SquareInt32(m_diameters.m_x));
Vec2i actualCoordinate = (m_2center + m_2offsetFromCenter);
actualCoordinate.m_x /= 2;
@@ -75,8 +78,8 @@ namespace PortabilityLayer
{
case Quadrant_PxPy:
{
const int32_t xStepCost = -m_xChangeCostDynamicFactor + m_xChangeCostStaticFactor;
const int32_t yStepCost = m_yChangeCostDynamicFactor + m_yChangeCostStaticFactor;
const int32_t xStepCost = -m_xChangeCostDynamicFactorOver4 + m_xChangeCostStaticFactorOver4;
const int32_t yStepCost = m_yChangeCostDynamicFactorOver4 + m_yChangeCostStaticFactorOver4;
const int32_t diagonalCostDelta = xStepCost + yStepCost;
@@ -85,7 +88,7 @@ namespace PortabilityLayer
// Diagonal movement will move closer to the edge (first octant)
IncrementY();
const int32_t distWithDiagonalMovement = m_sqDistFromEdge + xStepCost;
const int32_t distWithDiagonalMovement = m_sqDistFromEdgeOver4RoundedUp + xStepCost;
if (distWithDiagonalMovement >= 0)
{
DecrementX();
@@ -99,7 +102,7 @@ namespace PortabilityLayer
// Diagonal movement will move farther from the center (second octant)
DecrementX();
if (m_sqDistFromEdge < 0)
if (m_sqDistFromEdgeOver4RoundedUp < 0)
{
IncrementY();
plotDir = PlotDirection_NegX_PosY;
@@ -108,7 +111,7 @@ namespace PortabilityLayer
plotDir = PlotDirection_NegX_0Y;
}
if (m_xChangeCostDynamicFactor <= 0)
if (m_xChangeCostDynamicFactorOver4 <= 0)
m_quadrant = Quadrant_NxPy;
return plotDir;
@@ -117,8 +120,8 @@ namespace PortabilityLayer
case Quadrant_NxPy:
{
const int32_t xStepCost = -m_xChangeCostDynamicFactor + m_xChangeCostStaticFactor;
const int32_t yStepCost = -m_yChangeCostDynamicFactor + m_yChangeCostStaticFactor;
const int32_t xStepCost = -m_xChangeCostDynamicFactorOver4 + m_xChangeCostStaticFactorOver4;
const int32_t yStepCost = -m_yChangeCostDynamicFactorOver4 + m_yChangeCostStaticFactorOver4;
const int32_t diagonalCostDelta = xStepCost + yStepCost;
@@ -127,7 +130,7 @@ namespace PortabilityLayer
// Diagonal movement will move closer to the edge (first octant)
DecrementX();
const int32_t distWithDiagonalMovement = m_sqDistFromEdge + yStepCost;
const int32_t distWithDiagonalMovement = m_sqDistFromEdgeOver4RoundedUp + yStepCost;
if (distWithDiagonalMovement >= 0)
{
DecrementY();
@@ -141,7 +144,7 @@ namespace PortabilityLayer
// Diagonal movement will move farther from the center (second octant)
DecrementY();
if (m_sqDistFromEdge < 0)
if (m_sqDistFromEdgeOver4RoundedUp < 0)
{
DecrementX();
plotDir = PlotDirection_NegX_NegY;
@@ -150,7 +153,7 @@ namespace PortabilityLayer
plotDir = PlotDirection_0X_NegY;
}
if (m_yChangeCostDynamicFactor <= 0)
if (m_yChangeCostDynamicFactorOver4 <= 0)
m_quadrant = Quadrant_NxNy;
return plotDir;
@@ -159,8 +162,8 @@ namespace PortabilityLayer
case Quadrant_NxNy:
{
const int32_t xStepCost = m_xChangeCostDynamicFactor + m_xChangeCostStaticFactor;
const int32_t yStepCost = -m_yChangeCostDynamicFactor + m_yChangeCostStaticFactor;
const int32_t xStepCost = m_xChangeCostDynamicFactorOver4 + m_xChangeCostStaticFactorOver4;
const int32_t yStepCost = -m_yChangeCostDynamicFactorOver4 + m_yChangeCostStaticFactorOver4;
const int32_t diagonalCostDelta = xStepCost + yStepCost;
@@ -169,7 +172,7 @@ namespace PortabilityLayer
// Diagonal movement will move closer to the edge (first octant)
DecrementY();
const int32_t distWithDiagonalMovement = m_sqDistFromEdge + xStepCost;
const int32_t distWithDiagonalMovement = m_sqDistFromEdgeOver4RoundedUp + xStepCost;
if (distWithDiagonalMovement >= 0)
{
IncrementX();
@@ -183,7 +186,7 @@ namespace PortabilityLayer
// Diagonal movement will move farther from the center (second octant)
IncrementX();
if (m_sqDistFromEdge < 0)
if (m_sqDistFromEdgeOver4RoundedUp < 0)
{
DecrementY();
plotDir = PlotDirection_PosX_NegY;
@@ -192,7 +195,7 @@ namespace PortabilityLayer
plotDir = PlotDirection_PosX_0Y;
}
if (m_xChangeCostDynamicFactor >= 0)
if (m_xChangeCostDynamicFactorOver4 >= 0)
m_quadrant = Quadrant_PxNy;
return plotDir;
@@ -201,8 +204,8 @@ namespace PortabilityLayer
case Quadrant_PxNy:
{
const int32_t xStepCost = m_xChangeCostDynamicFactor + m_xChangeCostStaticFactor;
const int32_t yStepCost = m_yChangeCostDynamicFactor + m_yChangeCostStaticFactor;
const int32_t xStepCost = m_xChangeCostDynamicFactorOver4 + m_xChangeCostStaticFactorOver4;
const int32_t yStepCost = m_yChangeCostDynamicFactorOver4 + m_yChangeCostStaticFactorOver4;
const int32_t diagonalCostDelta = xStepCost + yStepCost;
@@ -211,7 +214,7 @@ namespace PortabilityLayer
// Diagonal movement will move closer to the edge (first octant)
IncrementX();
const int32_t distWithDiagonalMovement = m_sqDistFromEdge + yStepCost;
const int32_t distWithDiagonalMovement = m_sqDistFromEdgeOver4RoundedUp + yStepCost;
if (distWithDiagonalMovement >= 0)
{
IncrementY();
@@ -225,7 +228,7 @@ namespace PortabilityLayer
// Diagonal movement will move farther from the center
IncrementY();
if (m_sqDistFromEdge < 0)
if (m_sqDistFromEdgeOver4RoundedUp < 0)
{
IncrementX();
plotDir = PlotDirection_PosX_PosY;
@@ -234,7 +237,7 @@ namespace PortabilityLayer
plotDir = PlotDirection_0X_PosY;
}
if (m_yChangeCostDynamicFactor >= 0)
if (m_yChangeCostDynamicFactorOver4 >= 0)
m_quadrant = Quadrant_Finished;
return plotDir;
@@ -252,29 +255,31 @@ namespace PortabilityLayer
void EllipsePlotter::IncrementX()
{
const int32_t xStepCost = m_xChangeCostDynamicFactor + m_xChangeCostStaticFactor;
const int32_t xStepCost = m_xChangeCostDynamicFactorOver4 + m_xChangeCostStaticFactorOver4;
m_sqDistFromEdge += xStepCost;
m_xChangeCostDynamicFactor += m_xChangeCostDynamicFactorStep;
m_sqDistFromEdgeOver4RoundedUp += xStepCost;
m_xChangeCostDynamicFactorOver4 += m_xChangeCostDynamicFactorStepOver4;
m_point.m_x++;
#if PL_DEBUG_ELLIPSE_PLOTTER
m_2offsetFromCenter.m_x += 2;
m_sqDistFromEdge += xStepCost * 4;
#endif
}
bool EllipsePlotter::ConditionalIncrementX()
{
const int32_t xStepCost = m_xChangeCostDynamicFactor + m_xChangeCostStaticFactor;
const int32_t xStepCost = m_xChangeCostDynamicFactorOver4 + m_xChangeCostStaticFactorOver4;
if (m_sqDistFromEdge + xStepCost >= 0)
if (m_sqDistFromEdgeOver4RoundedUp + xStepCost >= 0)
{
m_sqDistFromEdge += xStepCost;
m_xChangeCostDynamicFactor += m_xChangeCostDynamicFactorStep;
m_sqDistFromEdgeOver4RoundedUp += xStepCost;
m_xChangeCostDynamicFactorOver4 += m_xChangeCostDynamicFactorStepOver4;
m_point.m_x++;
#if PL_DEBUG_ELLIPSE_PLOTTER
m_2offsetFromCenter.m_x += 2;
m_sqDistFromEdge += xStepCost * 4;
#endif
return true;
}
@@ -284,29 +289,31 @@ namespace PortabilityLayer
void EllipsePlotter::IncrementY()
{
const int32_t yStepCost = m_yChangeCostDynamicFactor + m_yChangeCostStaticFactor;
const int32_t yStepCost = m_yChangeCostDynamicFactorOver4 + m_yChangeCostStaticFactorOver4;
m_sqDistFromEdge += yStepCost;
m_yChangeCostDynamicFactor += m_yChangeCostDynamicFactorStep;
m_sqDistFromEdgeOver4RoundedUp += yStepCost;
m_yChangeCostDynamicFactorOver4 += m_yChangeCostDynamicFactorStepOver4;
m_point.m_y++;
#if PL_DEBUG_ELLIPSE_PLOTTER
m_2offsetFromCenter.m_y += 2;
m_sqDistFromEdge += yStepCost * 4;
#endif
}
bool EllipsePlotter::ConditionalIncrementY()
{
const int32_t yStepCost = m_yChangeCostDynamicFactor + m_yChangeCostStaticFactor;
const int32_t yStepCost = m_yChangeCostDynamicFactorOver4 + m_yChangeCostStaticFactorOver4;
if (m_sqDistFromEdge + yStepCost >= 0)
if (m_sqDistFromEdgeOver4RoundedUp + yStepCost >= 0)
{
m_sqDistFromEdge += yStepCost;
m_yChangeCostDynamicFactor += m_yChangeCostDynamicFactorStep;
m_sqDistFromEdgeOver4RoundedUp += yStepCost;
m_yChangeCostDynamicFactorOver4 += m_yChangeCostDynamicFactorStepOver4;
m_point.m_y++;
#if PL_DEBUG_ELLIPSE_PLOTTER
m_2offsetFromCenter.m_y += 2;
m_sqDistFromEdge += yStepCost * 4;
#endif
return true;
}
@@ -316,29 +323,31 @@ namespace PortabilityLayer
void EllipsePlotter::DecrementX()
{
const int32_t xStepCost = -m_xChangeCostDynamicFactor + m_xChangeCostStaticFactor;
const int32_t xStepCost = -m_xChangeCostDynamicFactorOver4 + m_xChangeCostStaticFactorOver4;
m_sqDistFromEdge += xStepCost;
m_xChangeCostDynamicFactor -= m_xChangeCostDynamicFactorStep;
m_sqDistFromEdgeOver4RoundedUp += xStepCost;
m_xChangeCostDynamicFactorOver4 -= m_xChangeCostDynamicFactorStepOver4;
m_point.m_x--;
#if PL_DEBUG_ELLIPSE_PLOTTER
m_2offsetFromCenter.m_x -= 2;
m_sqDistFromEdge += xStepCost * 4;
#endif
}
bool EllipsePlotter::ConditionalDecrementX()
{
const int32_t xStepCost = -m_xChangeCostDynamicFactor + m_xChangeCostStaticFactor;
const int32_t xStepCost = -m_xChangeCostDynamicFactorOver4 + m_xChangeCostStaticFactorOver4;
if (m_sqDistFromEdge + xStepCost >= 0)
if (m_sqDistFromEdgeOver4RoundedUp + xStepCost >= 0)
{
m_sqDistFromEdge += xStepCost;
m_xChangeCostDynamicFactor -= m_xChangeCostDynamicFactorStep;
m_sqDistFromEdgeOver4RoundedUp += xStepCost;
m_xChangeCostDynamicFactorOver4 -= m_xChangeCostDynamicFactorStepOver4;
m_point.m_x--;
#if PL_DEBUG_ELLIPSE_PLOTTER
m_2offsetFromCenter.m_x -= 2;
m_sqDistFromEdge += xStepCost * 4;
#endif
return true;
}
@@ -348,29 +357,31 @@ namespace PortabilityLayer
void EllipsePlotter::DecrementY()
{
const int32_t yStepCost = -m_yChangeCostDynamicFactor + m_yChangeCostStaticFactor;
const int32_t yStepCost = -m_yChangeCostDynamicFactorOver4 + m_yChangeCostStaticFactorOver4;
m_sqDistFromEdge += yStepCost;
m_yChangeCostDynamicFactor -= m_yChangeCostDynamicFactorStep;
m_sqDistFromEdgeOver4RoundedUp += yStepCost;
m_yChangeCostDynamicFactorOver4 -= m_yChangeCostDynamicFactorStepOver4;
m_point.m_y--;
#if PL_DEBUG_ELLIPSE_PLOTTER
m_2offsetFromCenter.m_y -= 2;
m_sqDistFromEdge += yStepCost * 4;
#endif
}
bool EllipsePlotter::ConditionalDecrementY()
{
const int32_t yStepCost = -m_yChangeCostDynamicFactor + m_yChangeCostStaticFactor;
const int32_t yStepCost = -m_yChangeCostDynamicFactorOver4 + m_yChangeCostStaticFactorOver4;
if (m_sqDistFromEdge + yStepCost >= 0)
if (m_sqDistFromEdgeOver4RoundedUp + yStepCost >= 0)
{
m_sqDistFromEdge += yStepCost;
m_yChangeCostDynamicFactor -= m_yChangeCostDynamicFactorStep;
m_sqDistFromEdgeOver4RoundedUp += yStepCost;
m_yChangeCostDynamicFactorOver4 -= m_yChangeCostDynamicFactorStepOver4;
m_point.m_y--;
#if PL_DEBUG_ELLIPSE_PLOTTER
m_2offsetFromCenter.m_y -= 2;
m_sqDistFromEdge += yStepCost * 4;
#endif
return true;
}
@@ -398,27 +409,28 @@ namespace PortabilityLayer
#if PL_DEBUG_ELLIPSE_PLOTTER
m_2offsetFromCenter = offsetFromCenterTimes2;
m_sqDistFromEdge = SquareInt32(offsetFromCenterTimes2.m_x * m_diameters.m_y) + SquareInt32(offsetFromCenterTimes2.m_y * m_diameters.m_x) - SquareInt32(m_diameters.m_x * m_diameters.m_y);
#endif
m_sqDistFromEdge = SquareInt32(offsetFromCenterTimes2.m_x * m_diameters.m_y) + SquareInt32(offsetFromCenterTimes2.m_y * m_diameters.m_x) - SquareInt32(m_diameters.m_x * m_diameters.m_y);
m_sqDistFromEdgeOver4RoundedUp = (SquareInt32(offsetFromCenterTimes2.m_x * m_diameters.m_y) + SquareInt32(offsetFromCenterTimes2.m_y * m_diameters.m_x) - SquareInt32(m_diameters.m_x * m_diameters.m_y) + 3) >> 2;
const int32_t xCostMultiplier = 4 * SquareInt32(m_diameters.m_y);
const int32_t yCostMultiplier = 4 * SquareInt32(m_diameters.m_x);
const int32_t xCostMultiplierOver4 = SquareInt32(m_diameters.m_y);
const int32_t yCostMultiplierOver4 = SquareInt32(m_diameters.m_x);
m_xChangeCostDynamicFactorStep = 2 * xCostMultiplier;
m_yChangeCostDynamicFactorStep = 2 * yCostMultiplier;
m_xChangeCostStaticFactor = 4 * SquareInt32(m_diameters.m_y);
m_yChangeCostStaticFactor = 4 * SquareInt32(m_diameters.m_x);
m_xChangeCostDynamicFactorStepOver4 = 2 * xCostMultiplierOver4;
m_yChangeCostDynamicFactorStepOver4 = 2 * yCostMultiplierOver4;
m_xChangeCostStaticFactorOver4 = SquareInt32(m_diameters.m_y);
m_yChangeCostStaticFactorOver4 = SquareInt32(m_diameters.m_x);
m_xChangeCostDynamicFactor = offsetFromCenterTimes2.m_x * xCostMultiplier;
m_yChangeCostDynamicFactor = offsetFromCenterTimes2.m_y * yCostMultiplier;
m_xChangeCostDynamicFactorOver4 = offsetFromCenterTimes2.m_x * xCostMultiplierOver4;
m_yChangeCostDynamicFactorOver4 = offsetFromCenterTimes2.m_y * yCostMultiplierOver4;
// On very wide ellipses (like 36x4), the point in the last column below the center may not be the first point in the row
// that is outside of the ellipse.
// Since the algorithm here is based on cost minimization, it is allowed to intersect the ellipse if the start and end points
// are both on or outside of the ellipse, so this violates the invariants.
// Therefore, we need to decrement X until this is not the case.
while (m_xChangeCostDynamicFactor - m_xChangeCostStaticFactor <= m_sqDistFromEdge)
while (m_xChangeCostDynamicFactorOver4 - m_xChangeCostStaticFactorOver4 <= m_sqDistFromEdgeOver4RoundedUp)
DecrementX();
}
}