bulk copy of latest physfs to our misc/libphysfs since this seems to fix an off-by-1 error reliably hit in readln read of 1 byte probably introduced in the addition of the buffered read. Whether this is excessive or whether libphysfs should even be maintained by us is another matter. But at least we shouldn't crash
(*
* Hedgewars, a free turn based strategy game
* Copyright (c) 2004-2015 Andrey Korotaev <unC0Rr@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*)
{$INCLUDE "options.inc"}
unit uCollisions;
interface
uses uFloat, uTypes;
const cMaxGearArrayInd = 1023;
type PGearArray = ^TGearArray;
TGearArray = record
ar: array[0..cMaxGearArrayInd] of PGear;
Count: Longword
end;
procedure initModule;
procedure freeModule;
procedure AddCI(Gear: PGear);
procedure DeleteCI(Gear: PGear);
function CheckGearsCollision(Gear: PGear): PGearArray;
function TestCollisionXwithGear(Gear: PGear; Dir: LongInt): Word;
function TestCollisionYwithGear(Gear: PGear; Dir: LongInt): Word;
function TestCollisionXKick(Gear: PGear; Dir: LongInt): Word;
function TestCollisionYKick(Gear: PGear; Dir: LongInt): Word;
function TestCollisionX(Gear: PGear; Dir: LongInt): Word;
function TestCollisionY(Gear: PGear; Dir: LongInt): Word;
function TestCollisionXwithXYShift(Gear: PGear; ShiftX: hwFloat; ShiftY: LongInt; Dir: LongInt): Word; inline;
function TestCollisionXwithXYShift(Gear: PGear; ShiftX: hwFloat; ShiftY: LongInt; Dir: LongInt; withGear: boolean): Word;
function TestCollisionYwithXYShift(Gear: PGear; ShiftX, ShiftY: LongInt; Dir: LongInt): Word; inline;
function TestCollisionYwithXYShift(Gear: PGear; ShiftX, ShiftY: LongInt; Dir: LongInt; withGear: boolean): Word;
function TestRectangleForObstacle(x1, y1, x2, y2: LongInt; landOnly: boolean): boolean;
function CheckCoordInWater(X, Y: LongInt): boolean; inline;
// returns: negative sign if going downhill to left, value is steepness (noslope/error = _0, 45 = _0_5)
function CalcSlopeBelowGear(Gear: PGear): hwFloat;
function CalcSlopeNearGear(Gear: PGear; dirX, dirY: LongInt): hwFloat;
function CalcSlopeTangent(Gear: PGear; collisionX, collisionY: LongInt; var outDeltaX, outDeltaY: LongInt; TestWord: LongWord): boolean;
implementation
uses uConsts, uLandGraphics, uVariables;
type TCollisionEntry = record
X, Y, Radius: LongInt;
cGear: PGear;
end;
const MAXRECTSINDEX = 1023;
var Count: Longword;
cinfos: array[0..MAXRECTSINDEX] of TCollisionEntry;
ga: TGearArray;
procedure AddCI(Gear: PGear);
begin
if (Gear^.CollisionIndex >= 0) or (Count > MAXRECTSINDEX) or
((Count > MAXRECTSINDEX-200) and ((Gear^.Kind = gtMine) or (Gear^.Kind = gtSMine) or (Gear^.Kind = gtKnife))) then
exit;
with cinfos[Count] do
begin
X:= hwRound(Gear^.X);
Y:= hwRound(Gear^.Y);
Radius:= Gear^.Radius;
ChangeRoundInLand(X, Y, Radius - 1, true, ((CurrentHedgehog <> nil) and (Gear = CurrentHedgehog^.Gear)) or ((Gear^.Kind = gtCase) and (Gear^.State and gstFrozen = 0)), Gear^.Kind = gtHedgehog);
cGear:= Gear
end;
Gear^.CollisionIndex:= Count;
inc(Count);
end;
procedure DeleteCI(Gear: PGear);
begin
if Gear^.CollisionIndex >= 0 then
begin
with cinfos[Gear^.CollisionIndex] do
ChangeRoundInLand(X, Y, Radius - 1, false, ((CurrentHedgehog <> nil) and (Gear = CurrentHedgehog^.Gear)) or ((Gear^.Kind = gtCase) and (Gear^.State and gstFrozen = 0)), Gear^.Kind = gtHedgehog);
cinfos[Gear^.CollisionIndex]:= cinfos[Pred(Count)];
cinfos[Gear^.CollisionIndex].cGear^.CollisionIndex:= Gear^.CollisionIndex;
Gear^.CollisionIndex:= -1;
dec(Count)
end;
end;
function CheckCoordInWater(X, Y: LongInt): boolean; inline;
begin
CheckCoordInWater:= (Y > cWaterLine)
or ((WorldEdge = weSea) and ((X < LongInt(leftX)) or (X > LongInt(rightX))));
end;
function CheckGearsCollision(Gear: PGear): PGearArray;
var mx, my, tr: LongInt;
i: Longword;
begin
CheckGearsCollision:= @ga;
ga.Count:= 0;
if Count = 0 then
exit;
mx:= hwRound(Gear^.X);
my:= hwRound(Gear^.Y);
tr:= Gear^.Radius + 2;
for i:= 0 to Pred(Count) do
with cinfos[i] do
if (Gear <> cGear) and
(sqr(mx - x) + sqr(my - y) <= sqr(Radius + tr)) then
begin
ga.ar[ga.Count]:= cinfos[i].cGear;
inc(ga.Count)
end
end;
function TestCollisionXwithGear(Gear: PGear; Dir: LongInt): Word;
var x, y, i: LongInt;
begin
// Special case to emulate the old intersect gear clearing, but with a bit of slop for pixel overlap
if (Gear^.CollisionMask = lfNotCurrentMask) and (Gear^.Kind <> gtHedgehog) and (Gear^.Hedgehog <> nil) and (Gear^.Hedgehog^.Gear <> nil) and
((hwRound(Gear^.Hedgehog^.Gear^.X) + Gear^.Hedgehog^.Gear^.Radius + 16 < hwRound(Gear^.X) - Gear^.Radius) or
(hwRound(Gear^.Hedgehog^.Gear^.X) - Gear^.Hedgehog^.Gear^.Radius - 16 > hwRound(Gear^.X) + Gear^.Radius)) then
Gear^.CollisionMask:= $FFFF;
x:= hwRound(Gear^.X);
if Dir < 0 then
x:= x - Gear^.Radius
else
x:= x + Gear^.Radius;
if (x and LAND_WIDTH_MASK) = 0 then
begin
y:= hwRound(Gear^.Y) - Gear^.Radius + 1;
i:= y + Gear^.Radius * 2 - 2;
repeat
if (y and LAND_HEIGHT_MASK) = 0 then
if Land[y, x] and Gear^.CollisionMask <> 0 then
exit(Land[y, x] and Gear^.CollisionMask);
inc(y)
until (y > i);
end;
TestCollisionXwithGear:= 0
end;
function TestCollisionYwithGear(Gear: PGear; Dir: LongInt): Word;
var x, y, i: LongInt;
begin
// Special case to emulate the old intersect gear clearing, but with a bit of slop for pixel overlap
if (Gear^.CollisionMask = lfNotCurrentMask) and (Gear^.Kind <> gtHedgehog) and (Gear^.Hedgehog <> nil) and (Gear^.Hedgehog^.Gear <> nil) and
((hwRound(Gear^.Hedgehog^.Gear^.Y) + Gear^.Hedgehog^.Gear^.Radius + 16 < hwRound(Gear^.Y) - Gear^.Radius) or
(hwRound(Gear^.Hedgehog^.Gear^.Y) - Gear^.Hedgehog^.Gear^.Radius - 16 > hwRound(Gear^.Y) + Gear^.Radius)) then
Gear^.CollisionMask:= $FFFF;
y:= hwRound(Gear^.Y);
if Dir < 0 then
y:= y - Gear^.Radius
else
y:= y + Gear^.Radius;
if (y and LAND_HEIGHT_MASK) = 0 then
begin
x:= hwRound(Gear^.X) - Gear^.Radius + 1;
i:= x + Gear^.Radius * 2 - 2;
repeat
if (x and LAND_WIDTH_MASK) = 0 then
if Land[y, x] and Gear^.CollisionMask <> 0 then
begin
exit(Land[y, x] and Gear^.CollisionMask)
end;
inc(x)
until (x > i);
end;
TestCollisionYwithGear:= 0
end;
function TestCollisionXKick(Gear: PGear; Dir: LongInt): Word;
var x, y, mx, my, i: LongInt;
pixel: Word;
begin
pixel:= 0;
x:= hwRound(Gear^.X);
if Dir < 0 then
x:= x - Gear^.Radius
else
x:= x + Gear^.Radius;
if (x and LAND_WIDTH_MASK) = 0 then
begin
y:= hwRound(Gear^.Y) - Gear^.Radius + 1;
i:= y + Gear^.Radius * 2 - 2;
repeat
if (y and LAND_HEIGHT_MASK) = 0 then
begin
if Land[y, x] and Gear^.CollisionMask <> 0 then
begin
if Land[y, x] and Gear^.CollisionMask > 255 then
exit(Land[y, x] and Gear^.CollisionMask)
else
pixel:= Land[y, x] and Gear^.CollisionMask;
end;
end;
inc(y)
until (y > i);
end;
TestCollisionXKick:= pixel;
if pixel <> 0 then
begin
if hwAbs(Gear^.dX) < cHHKick then
exit;
if (Gear^.State and gstHHJumping <> 0)
and (hwAbs(Gear^.dX) < _0_4) then
exit;
mx:= hwRound(Gear^.X);
my:= hwRound(Gear^.Y);
for i:= 0 to Pred(Count) do
with cinfos[i] do
if (Gear <> cGear) and
((mx > x) xor (Dir > 0)) and
(
((cGear^.Kind in [gtHedgehog, gtMine, gtKnife]) and ((Gear^.State and gstNotKickable) = 0)) or
// only apply X kick if the barrel is knocked over
((cGear^.Kind = gtExplosives) and ((cGear^.State and gsttmpflag) <> 0))
) and
(sqr(mx - x) + sqr(my - y) <= sqr(Radius + Gear^.Radius + 2)) then
begin
with cGear^ do
begin
dX:= Gear^.dX;
dY:= Gear^.dY * _0_5;
State:= State or gstMoving;
if Kind = gtKnife then State:= State and (not gstCollision);
Active:= true
end;
DeleteCI(cGear);
exit(0);
end
end
end;
function TestCollisionYKick(Gear: PGear; Dir: LongInt): Word;
var x, y, mx, my, myr, i: LongInt;
pixel: Word;
begin
pixel:= 0;
y:= hwRound(Gear^.Y);
if Dir < 0 then
y:= y - Gear^.Radius
else
y:= y + Gear^.Radius;
if (y and LAND_HEIGHT_MASK) = 0 then
begin
x:= hwRound(Gear^.X) - Gear^.Radius + 1;
i:= x + Gear^.Radius * 2 - 2;
repeat
if (x and LAND_WIDTH_MASK) = 0 then
if Land[y, x] > 0 then
begin
if Land[y, x] and Gear^.CollisionMask > 255 then
exit(Land[y, x] and Gear^.CollisionMask)
else // if Land[y, x] <> 0 then
pixel:= Land[y, x] and Gear^.CollisionMask;
end;
inc(x)
until (x > i);
end;
TestCollisionYKick:= pixel;
if pixel <> 0 then
begin
if hwAbs(Gear^.dY) < cHHKick then
exit;
if (Gear^.State and gstHHJumping <> 0) and (not Gear^.dY.isNegative) and (Gear^.dY < _0_4) then
exit;
mx:= hwRound(Gear^.X);
my:= hwRound(Gear^.Y);
myr:= my+Gear^.Radius;
for i:= 0 to Pred(Count) do
with cinfos[i] do
if (Gear <> cGear) and
((myr > y) xor (Dir > 0)) and
(Gear^.State and gstNotKickable = 0) and
(cGear^.Kind in [gtHedgehog, gtMine, gtKnife, gtExplosives]) and
(sqr(mx - x) + sqr(my - y) <= sqr(Radius + Gear^.Radius + 2)) then
begin
with cGear^ do
begin
if (Kind <> gtExplosives) or ((State and gsttmpflag) <> 0) then
dX:= Gear^.dX * _0_5;
dY:= Gear^.dY;
State:= State or gstMoving;
if Kind = gtKnife then State:= State and (not gstCollision);
Active:= true
end;
DeleteCI(cGear);
exit(0)
end
end
end;
function TestCollisionXwithXYShift(Gear: PGear; ShiftX: hwFloat; ShiftY: LongInt; Dir: LongInt): Word; inline;
begin
TestCollisionXwithXYShift:= TestCollisionXwithXYShift(Gear, ShiftX, ShiftY, Dir, true);
end;
function TestCollisionXwithXYShift(Gear: PGear; ShiftX: hwFloat; ShiftY: LongInt; Dir: LongInt; withGear: boolean): Word;
begin
Gear^.X:= Gear^.X + ShiftX;
Gear^.Y:= Gear^.Y + int2hwFloat(ShiftY);
if withGear then
TestCollisionXwithXYShift:= TestCollisionXwithGear(Gear, Dir)
else TestCollisionXwithXYShift:= TestCollisionX(Gear, Dir);
Gear^.X:= Gear^.X - ShiftX;
Gear^.Y:= Gear^.Y - int2hwFloat(ShiftY)
end;
function TestCollisionX(Gear: PGear; Dir: LongInt): Word;
var x, y, i: LongInt;
begin
x:= hwRound(Gear^.X);
if Dir < 0 then
x:= x - Gear^.Radius
else
x:= x + Gear^.Radius;
if (x and LAND_WIDTH_MASK) = 0 then
begin
y:= hwRound(Gear^.Y) - Gear^.Radius + 1;
i:= y + Gear^.Radius * 2 - 2;
repeat
if (y and LAND_HEIGHT_MASK) = 0 then
if Land[y, x] and Gear^.CollisionMask > 255 then
exit(Land[y, x] and Gear^.CollisionMask);
inc(y)
until (y > i);
end;
TestCollisionX:= 0
end;
function TestCollisionY(Gear: PGear; Dir: LongInt): Word;
var x, y, i: LongInt;
begin
y:= hwRound(Gear^.Y);
if Dir < 0 then
y:= y - Gear^.Radius
else
y:= y + Gear^.Radius;
if (y and LAND_HEIGHT_MASK) = 0 then
begin
x:= hwRound(Gear^.X) - Gear^.Radius + 1;
i:= x + Gear^.Radius * 2 - 2;
repeat
if (x and LAND_WIDTH_MASK) = 0 then
if Land[y, x] and Gear^.CollisionMask > 255 then
exit(Land[y, x] and Gear^.CollisionMask);
inc(x)
until (x > i);
end;
TestCollisionY:= 0
end;
function TestCollisionYwithXYShift(Gear: PGear; ShiftX, ShiftY: LongInt; Dir: LongInt): Word; inline;
begin
TestCollisionYwithXYShift:= TestCollisionYwithXYShift(Gear, ShiftX, ShiftY, Dir, true);
end;
function TestCollisionYwithXYShift(Gear: PGear; ShiftX, ShiftY: LongInt; Dir: LongInt; withGear: boolean): Word;
begin
Gear^.X:= Gear^.X + int2hwFloat(ShiftX);
Gear^.Y:= Gear^.Y + int2hwFloat(ShiftY);
if withGear then
TestCollisionYwithXYShift:= TestCollisionYwithGear(Gear, Dir)
else
TestCollisionYwithXYShift:= TestCollisionY(Gear, Dir);
Gear^.X:= Gear^.X - int2hwFloat(ShiftX);
Gear^.Y:= Gear^.Y - int2hwFloat(ShiftY)
end;
function TestRectangleForObstacle(x1, y1, x2, y2: LongInt; landOnly: boolean): boolean;
var x, y: LongInt;
TestWord: LongWord;
begin
TestRectangleForObstacle:= true;
if landOnly then
TestWord:= 255
else
TestWord:= 0;
if x1 > x2 then
begin
x := x1;
x1 := x2;
x2 := x;
end;
if y1 > y2 then
begin
y := y1;
y1 := y2;
y2 := y;
end;
if (hasBorder and ((y1 < 0) or (x1 < 0) or (x2 > LAND_WIDTH))) then
exit;
for y := y1 to y2 do
for x := x1 to x2 do
if ((y and LAND_HEIGHT_MASK) = 0) and ((x and LAND_WIDTH_MASK) = 0) and (Land[y, x] > TestWord) then
exit;
TestRectangleForObstacle:= false
end;
function CalcSlopeTangent(Gear: PGear; collisionX, collisionY: LongInt; var outDeltaX, outDeltaY: LongInt; TestWord: LongWord): boolean;
var ldx, ldy, rdx, rdy: LongInt;
i, j, k, mx, my, li, ri, jfr, jto, tmpo : ShortInt;
tmpx, tmpy: LongWord;
dx, dy, s: hwFloat;
offset: array[0..7,0..1] of ShortInt;
isColl: Boolean;
begin
CalcSlopeTangent:= false;
dx:= Gear^.dX;
dy:= Gear^.dY;
// we start searching from the direction the gear came from
if (dx.QWordValue > _0_995.QWordValue )
or (dy.QWordValue > _0_995.QWordValue ) then
begin // scale
s := _0_995 / Distance(dx,dy);
dx := s * dx;
dy := s * dy;
end;
mx:= hwRound(Gear^.X-dx) - hwRound(Gear^.X);
my:= hwRound(Gear^.Y-dy) - hwRound(Gear^.Y);
li:= -1;
ri:= -1;
// go around collision pixel, checking for first/last collisions
// this will determinate what angles will be tried to crawl along
for i:= 0 to 7 do
begin
offset[i,0]:= mx;
offset[i,1]:= my;
// multiplicator k tries to skip small pixels/gaps when possible
for k:= 4 downto 1 do
begin
tmpx:= collisionX + k * mx;
tmpy:= collisionY + k * my;
if (((tmpy) and LAND_HEIGHT_MASK) = 0) and (((tmpx) and LAND_WIDTH_MASK) = 0) then
if (Land[tmpy,tmpx] > TestWord) then
begin
// remember the index belonging to the first and last collision (if in 1st half)
if (i <> 0) then
begin
if (ri = -1) then
ri:= i
else
li:= i;
end;
end;
end;
if i = 7 then
break;
// prepare offset for next check (clockwise)
if (mx = -1) and (my <> -1) then
my:= my - 1
else if (my = -1) and (mx <> 1) then
mx:= mx + 1
else if (mx = 1) and (my <> 1) then
my:= my + 1
else
mx:= mx - 1;
end;
ldx:= collisionX;
ldy:= collisionY;
rdx:= collisionX;
rdy:= collisionY;
// edge-crawl
for i:= 0 to 8 do
begin
// using mx,my as temporary value buffer here
jfr:= 8+li+1;
jto:= 8+li-1;
isColl:= false;
for j:= jfr downto jto do
begin
tmpo:= j mod 8;
// multiplicator k tries to skip small pixels/gaps when possible
for k:= 3 downto 1 do
begin
tmpx:= ldx + k * offset[tmpo,0];
tmpy:= ldy + k * offset[tmpo,1];
if (((tmpy) and LAND_HEIGHT_MASK) = 0) and (((tmpx) and LAND_WIDTH_MASK) = 0)
and (Land[tmpy,tmpx] > TestWord) then
begin
ldx:= tmpx;
ldy:= tmpy;
isColl:= true;
break;
end;
end;
if isColl then
break;
end;
jfr:= 8+ri-1;
jto:= 8+ri+1;
isColl:= false;
for j:= jfr to jto do
begin
tmpo:= j mod 8;
for k:= 3 downto 1 do
begin
tmpx:= rdx + k * offset[tmpo,0];
tmpy:= rdy + k * offset[tmpo,1];
if (((tmpy) and LAND_HEIGHT_MASK) = 0) and (((tmpx) and LAND_WIDTH_MASK) = 0)
and (Land[tmpy,tmpx] > TestWord) then
begin
rdx:= tmpx;
rdy:= tmpy;
isColl:= true;
break;
end;
end;
if isColl then
break;
end;
end;
ldx:= rdx - ldx;
ldy:= rdy - ldy;
if ((ldx = 0) and (ldy = 0)) then
exit;
outDeltaX:= ldx;
outDeltaY:= ldy;
CalcSlopeTangent:= true;
end;
function CalcSlopeNearGear(Gear: PGear; dirX, dirY: LongInt): hwFloat;
var dx, dy: hwFloat;
collX, collY, i, y, x, gx, gy, sdx, sdy: LongInt;
isColl, bSucc: Boolean;
begin
if dirY <> 0 then
begin
y:= hwRound(Gear^.Y) + Gear^.Radius * dirY;
gx:= hwRound(Gear^.X);
collX := gx;
isColl:= false;
if (y and LAND_HEIGHT_MASK) = 0 then
begin
x:= hwRound(Gear^.X) - Gear^.Radius + 1;
i:= x + Gear^.Radius * 2 - 2;
repeat
if (x and LAND_WIDTH_MASK) = 0 then
if Land[y, x] <> 0 then
if (not isColl) or (abs(x-gx) < abs(collX-gx)) then
begin
isColl:= true;
collX := x;
end;
inc(x)
until (x > i);
end;
end
else
begin
x:= hwRound(Gear^.X) + Gear^.Radius * dirX;
gy:= hwRound(Gear^.Y);
collY := gy;
isColl:= false;
if (x and LAND_WIDTH_MASK) = 0 then
begin
y:= hwRound(Gear^.Y) - Gear^.Radius + 1;
i:= y + Gear^.Radius * 2 - 2;
repeat
if (y and LAND_HEIGHT_MASK) = 0 then
if Land[y, x] <> 0 then
if (not isColl) or (abs(y-gy) < abs(collY-gy)) then
begin
isColl:= true;
collY := y;
end;
inc(y)
until (y > i);
end;
end;
if isColl then
begin
// save original dx/dy
dx := Gear^.dX;
dy := Gear^.dY;
if dirY <> 0 then
begin
Gear^.dX.QWordValue:= 0;
Gear^.dX.isNegative:= (collX >= gx);
Gear^.dY:= _1*dirY
end
else
begin
Gear^.dY.QWordValue:= 0;
Gear^.dY.isNegative:= (collY >= gy);
Gear^.dX:= _1*dirX
end;
sdx:= 0;
sdy:= 0;
if dirY <> 0 then
bSucc := CalcSlopeTangent(Gear, collX, y, sdx, sdy, 0)
else bSucc := CalcSlopeTangent(Gear, x, collY, sdx, sdy, 0);
// restore original dx/dy
Gear^.dX := dx;
Gear^.dY := dy;
if bSucc and ((sdx <> 0) or (sdy <> 0)) then
begin
dx := int2hwFloat(sdy) / (abs(sdx) + abs(sdy));
dx.isNegative := (sdx * sdy) < 0;
exit (dx);
end
end;
CalcSlopeNearGear := _0;
end;
function CalcSlopeBelowGear(Gear: PGear): hwFloat;
var dx, dy: hwFloat;
collX, i, y, x, gx, sdx, sdy: LongInt;
isColl, bSucc: Boolean;
begin
y:= hwRound(Gear^.Y) + Gear^.Radius;
gx:= hwRound(Gear^.X);
collX := gx;
isColl:= false;
if (y and LAND_HEIGHT_MASK) = 0 then
begin
x:= hwRound(Gear^.X) - Gear^.Radius + 1;
i:= x + Gear^.Radius * 2 - 2;
repeat
if (x and LAND_WIDTH_MASK) = 0 then
if Land[y, x] > 255 then
if (not isColl) or (abs(x-gx) < abs(collX-gx)) then
begin
isColl:= true;
collX := x;
end;
inc(x)
until (x > i);
end;
if isColl then
begin
// save original dx/dy
dx := Gear^.dX;
dy := Gear^.dY;
Gear^.dX.QWordValue:= 0;
Gear^.dX.isNegative:= (collX >= gx);
Gear^.dY:= _1;
sdx:= 0;
sdy:= 0;
bSucc := CalcSlopeTangent(Gear, collX, y, sdx, sdy, 255);
// restore original dx/dy
Gear^.dX := dx;
Gear^.dY := dy;
if bSucc and (sdx <> 0) and (sdy <> 0) then
begin
dx := int2hwFloat(sdy) / (abs(sdx) + abs(sdy));
dx.isNegative := (sdx * sdy) < 0;
exit (dx);
end;
end;
CalcSlopeBelowGear := _0;
end;
procedure initModule;
begin
Count:= 0;
end;
procedure freeModule;
begin
end;
end.