(*
* Hedgewars, a free turn based strategy game
* Copyright (c) 2004-2011 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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 AddGearCI(Gear: PGear);
procedure DeleteCI(Gear: PGear);
function CheckGearsCollision(Gear: PGear): PGearArray;
function TestCollisionXwithGear(Gear: PGear; Dir: LongInt): boolean;
function TestCollisionYwithGear(Gear: PGear; Dir: LongInt): Word;
function TestCollisionXKick(Gear: PGear; Dir: LongInt): boolean;
function TestCollisionYKick(Gear: PGear; Dir: LongInt): boolean;
function TestCollisionX(Gear: PGear; Dir: LongInt): boolean;
function TestCollisionY(Gear: PGear; Dir: LongInt): boolean;
function TestCollisionXwithXYShift(Gear: PGear; ShiftX: hwFloat; ShiftY: LongInt; Dir: LongInt; withGear: boolean = true): boolean;
function TestCollisionYwithXYShift(Gear: PGear; ShiftX, ShiftY: LongInt; Dir: LongInt; withGear: boolean = true): boolean;
function TestRectancleForObstacle(x1, y1, x2, y2: LongInt; landOnly: boolean): boolean;
// returns: negative sign if going downhill to left, value is steepness (noslope/error = _0, 45° = _0_5)
function CalcSlopeBelowGear(Gear: PGear): hwFloat;
function CalcSlopeTangent(Gear: PGear; collisionX, collisionY: LongInt; var outDeltaX, outDeltaY: LongInt; TestWord: LongWord): Boolean;
implementation
uses uConsts, uLandGraphics, uVariables, uDebug, uGears;
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 AddGearCI(Gear: PGear);
var t: PGear;
begin
if Gear^.CollisionIndex >= 0 then exit;
TryDo(Count <= MAXRECTSINDEX, 'Collision rects array overflow', true);
with cinfos[Count] do
begin
X:= hwRound(Gear^.X);
Y:= hwRound(Gear^.Y);
Radius:= Gear^.Radius;
ChangeRoundInLand(X, Y, Radius - 1, true);
cGear:= Gear
end;
Gear^.CollisionIndex:= Count;
inc(Count);
// mines are the easiest way to overflow collision
if (Count > (MAXRECTSINDEX-20)) then
begin
t:= GearsList;
while (t <> nil) and (t^.Kind <> gtMine) do
t:= t^.NextGear;
if (t <> nil) then DeleteGear(t)
end;
end;
procedure DeleteCI(Gear: PGear);
begin
if Gear^.CollisionIndex >= 0 then
begin
with cinfos[Gear^.CollisionIndex] do
ChangeRoundInLand(X, Y, Radius - 1, false);
cinfos[Gear^.CollisionIndex]:= cinfos[Pred(Count)];
cinfos[Gear^.CollisionIndex].cGear^.CollisionIndex:= Gear^.CollisionIndex;
Gear^.CollisionIndex:= -1;
dec(Count)
end;
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): boolean;
var x, y, i: LongInt;
TestWord: LongWord;
begin
if Gear^.IntersectGear <> nil then
with Gear^ do
if (hwRound(IntersectGear^.X) + IntersectGear^.Radius < hwRound(X) - Radius) or
(hwRound(IntersectGear^.X) - IntersectGear^.Radius > hwRound(X) + Radius) then
begin
IntersectGear:= nil;
TestWord:= 0
end else
TestWord:= 255
else TestWord:= 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
if Land[y, x] > TestWord then exit(true);
inc(y)
until (y > i);
end;
TestCollisionXwithGear:= false
end;
function TestCollisionYwithGear(Gear: PGear; Dir: LongInt): Word;
var x, y, i: LongInt;
TestWord: LongWord;
begin
if Gear^.IntersectGear <> nil then
with Gear^ do
if (hwRound(IntersectGear^.Y) + IntersectGear^.Radius < hwRound(Y) - Radius) or
(hwRound(IntersectGear^.Y) - IntersectGear^.Radius > hwRound(Y) + Radius) then
begin
IntersectGear:= nil;
TestWord:= 0
end else
TestWord:= 255
else TestWord:= 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] > TestWord then exit(Land[y, x]);
inc(x)
until (x > i);
end;
TestCollisionYwithGear:= 0
end;
function TestCollisionXKick(Gear: PGear; Dir: LongInt): boolean;
var x, y, mx, my, i: LongInt;
flag: boolean;
begin
flag:= false;
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] > 255 then exit(true)
else if Land[y, x] <> 0 then flag:= true;
inc(y)
until (y > i);
end;
TestCollisionXKick:= flag;
if flag 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
(sqr(mx - x) + sqr(my - y) <= sqr(Radius + Gear^.Radius + 2)) and
((mx > x) xor (Dir > 0)) then
if ((cGear^.Kind in [gtHedgehog, gtMine]) 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)) then
begin
with cGear^ do
begin
dX:= Gear^.dX;
dY:= Gear^.dY * _0_5;
State:= State or gstMoving;
Active:= true
end;
DeleteCI(cGear);
exit(false)
end
end
end;
function TestCollisionYKick(Gear: PGear; Dir: LongInt): boolean;
var x, y, mx, my, i: LongInt;
flag: boolean;
begin
flag:= false;
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
if Land[y, x] > 255 then exit(true)
else if Land[y, x] <> 0 then flag:= true;
inc(x)
until (x > i);
end;
TestCollisionYKick:= flag;
if flag then
begin
if hwAbs(Gear^.dY) < cHHKick then exit(true);
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);
for i:= 0 to Pred(Count) do
with cinfos[i] do
if (Gear <> cGear) and
(sqr(mx - x) + sqr(my - y) <= sqr(Radius + Gear^.Radius + 2)) and
((my > y) xor (Dir > 0)) then
if (cGear^.Kind in [gtHedgehog, gtMine, gtExplosives]) and ((Gear^.State and gstNotKickable) = 0) 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;
Active:= true
end;
DeleteCI(cGear);
exit(false)
end
end
end;
function TestCollisionXwithXYShift(Gear: PGear; ShiftX: hwFloat; ShiftY: LongInt; Dir: LongInt; withGear: boolean = true): boolean;
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): boolean;
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] > 255 then exit(true);
inc(y)
until (y > i);
end;
TestCollisionX:= false
end;
function TestCollisionY(Gear: PGear; Dir: LongInt): boolean;
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] > 255 then exit(true);
inc(x)
until (x > i);
end;
TestCollisionY:= false
end;
function TestCollisionYwithXYShift(Gear: PGear; ShiftX, ShiftY: LongInt; Dir: LongInt; withGear: boolean = true): boolean;
begin
Gear^.X:= Gear^.X + int2hwFloat(ShiftX);
Gear^.Y:= Gear^.Y + int2hwFloat(ShiftY);
if withGear then TestCollisionYwithXYShift:= TestCollisionYwithGear(Gear, Dir) <> 0
else TestCollisionYwithXYShift:= TestCollisionY(Gear, Dir);
Gear^.X:= Gear^.X - int2hwFloat(ShiftX);
Gear^.Y:= Gear^.Y - int2hwFloat(ShiftY)
end;
function TestRectancleForObstacle(x1, y1, x2, y2: LongInt; landOnly: boolean): boolean;
var x, y: LongInt;
TestWord: LongWord;
begin
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(true);
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(true);
TestRectancleForObstacle:= 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
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(false);
outDeltaX:= ldx;
outDeltaY:= ldy;
exit(true);
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.