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Diffstat (limited to 'src/uqm/collide.c')
| -rw-r--r-- | src/uqm/collide.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/src/uqm/collide.c b/src/uqm/collide.c new file mode 100644 index 0000000..7275e42 --- /dev/null +++ b/src/uqm/collide.c @@ -0,0 +1,183 @@ +//Copyright Paul Reiche, Fred Ford. 1992-2002 + +/* + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * 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 "collide.h" +#include "element.h" +#include "races.h" +#include "units.h" +#include "libs/mathlib.h" +#include "libs/log.h" + + +//#define DEBUG_COLLIDE + +void +collide (ELEMENT *ElementPtr0, ELEMENT *ElementPtr1) +{ + SIZE speed; + SIZE dx0, dy0, dx1, dy1, dx_rel, dy_rel; + SIZE TravelAngle0, TravelAngle1, ImpactAngle0, ImpactAngle1; + SIZE RelTravelAngle, Directness; + + dx_rel = ElementPtr0->next.location.x + - ElementPtr1->next.location.x; + dy_rel = ElementPtr0->next.location.y + - ElementPtr1->next.location.y; + ImpactAngle0 = ARCTAN (dx_rel, dy_rel); + ImpactAngle1 = NORMALIZE_ANGLE (ImpactAngle0 + HALF_CIRCLE); + + GetCurrentVelocityComponents (&ElementPtr0->velocity, &dx0, &dy0); + TravelAngle0 = GetVelocityTravelAngle (&ElementPtr0->velocity); + GetCurrentVelocityComponents (&ElementPtr1->velocity, &dx1, &dy1); + TravelAngle1 = GetVelocityTravelAngle (&ElementPtr1->velocity); + dx_rel = dx0 - dx1; + dy_rel = dy0 - dy1; + RelTravelAngle = ARCTAN (dx_rel, dy_rel); + speed = square_root ((long)dx_rel * dx_rel + (long)dy_rel * dy_rel); + + Directness = NORMALIZE_ANGLE (RelTravelAngle - ImpactAngle0); + if (Directness <= QUADRANT || Directness >= HALF_CIRCLE + QUADRANT) + /* shapes just scraped each other but still collided, + * they will collide again unless we fudge it. + */ + { + Directness = HALF_CIRCLE; + ImpactAngle0 = TravelAngle0 + HALF_CIRCLE; + ImpactAngle1 = TravelAngle1 + HALF_CIRCLE; + } + +#ifdef DEBUG_COLLIDE + log_add (log_Debug, "Centers: <%d, %d> <%d, %d>", + ElementPtr0->next.location.x, ElementPtr0->next.location.y, + ElementPtr1->next.location.x, ElementPtr1->next.location.y); + log_add (log_Debug, "RelTravelAngle : %d, ImpactAngles <%d, %d>", + RelTravelAngle, ImpactAngle0, ImpactAngle1); +#endif /* DEBUG_COLLIDE */ + + if (ElementPtr0->next.location.x == ElementPtr0->current.location.x + && ElementPtr0->next.location.y == ElementPtr0->current.location.y + && ElementPtr1->next.location.x == ElementPtr1->current.location.x + && ElementPtr1->next.location.y == ElementPtr1->current.location.y) + { + if (ElementPtr0->state_flags & ElementPtr1->state_flags & DEFY_PHYSICS) + { + ImpactAngle0 = TravelAngle0 + (HALF_CIRCLE - OCTANT); + ImpactAngle1 = TravelAngle1 + (HALF_CIRCLE - OCTANT); + ZeroVelocityComponents (&ElementPtr0->velocity); + ZeroVelocityComponents (&ElementPtr1->velocity); + } + ElementPtr0->state_flags |= (DEFY_PHYSICS | COLLISION); + ElementPtr1->state_flags |= (DEFY_PHYSICS | COLLISION); +#ifdef DEBUG_COLLIDE + log_add (log_Debug, "No movement before collision -- " + "<(%d, %d) = %d, (%d, %d) = %d>", + dx0, dy0, ImpactAngle0 - OCTANT, dx1, dy1, + ImpactAngle1 - OCTANT); +#endif /* DEBUG_COLLIDE */ + } + + { + SIZE mass0, mass1; + long scalar; + + mass0 = ElementPtr0->mass_points /* << 2 */; + mass1 = ElementPtr1->mass_points /* << 2 */; + scalar = (long)SINE (Directness, speed << 1) * (mass0 * mass1); + + if (!GRAVITY_MASS (ElementPtr0->mass_points + 1)) + { + if (ElementPtr0->state_flags & PLAYER_SHIP) + { + STARSHIP *StarShipPtr; + + GetElementStarShip (ElementPtr0, &StarShipPtr); + StarShipPtr->cur_status_flags &= + ~(SHIP_AT_MAX_SPEED | SHIP_BEYOND_MAX_SPEED); + if (!(ElementPtr0->state_flags & DEFY_PHYSICS)) + { + if (ElementPtr0->turn_wait < COLLISION_TURN_WAIT) + ElementPtr0->turn_wait += COLLISION_TURN_WAIT; + if (ElementPtr0->thrust_wait < COLLISION_THRUST_WAIT) + ElementPtr0->thrust_wait += COLLISION_THRUST_WAIT; + } + } + + speed = (SIZE)(scalar / ((long)mass0 * (mass0 + mass1))); + DeltaVelocityComponents (&ElementPtr0->velocity, + COSINE (ImpactAngle0, speed), + SINE (ImpactAngle0, speed)); + + GetCurrentVelocityComponents (&ElementPtr0->velocity, &dx0, &dy0); + if (dx0 < 0) + dx0 = -dx0; + if (dy0 < 0) + dy0 = -dy0; + + if (VELOCITY_TO_WORLD (dx0 + dy0) < SCALED_ONE) + SetVelocityComponents (&ElementPtr0->velocity, + COSINE (ImpactAngle0, + WORLD_TO_VELOCITY (SCALED_ONE) - 1), + SINE (ImpactAngle0, + WORLD_TO_VELOCITY (SCALED_ONE) - 1)); + } + + if (!GRAVITY_MASS (ElementPtr1->mass_points + 1)) + { + if (ElementPtr1->state_flags & PLAYER_SHIP) + { + STARSHIP *StarShipPtr; + + GetElementStarShip (ElementPtr1, &StarShipPtr); + StarShipPtr->cur_status_flags &= + ~(SHIP_AT_MAX_SPEED | SHIP_BEYOND_MAX_SPEED); + if (!(ElementPtr1->state_flags & DEFY_PHYSICS)) + { + if (ElementPtr1->turn_wait < COLLISION_TURN_WAIT) + ElementPtr1->turn_wait += COLLISION_TURN_WAIT; + if (ElementPtr1->thrust_wait < COLLISION_THRUST_WAIT) + ElementPtr1->thrust_wait += COLLISION_THRUST_WAIT; + } + } + + speed = (SIZE)(scalar / ((long)mass1 * (mass0 + mass1))); + DeltaVelocityComponents (&ElementPtr1->velocity, + COSINE (ImpactAngle1, speed), + SINE (ImpactAngle1, speed)); + + GetCurrentVelocityComponents (&ElementPtr1->velocity, &dx1, &dy1); + if (dx1 < 0) + dx1 = -dx1; + if (dy1 < 0) + dy1 = -dy1; + + if (VELOCITY_TO_WORLD (dx1 + dy1) < SCALED_ONE) + SetVelocityComponents (&ElementPtr1->velocity, + COSINE (ImpactAngle1, + WORLD_TO_VELOCITY (SCALED_ONE) - 1), + SINE (ImpactAngle1, + WORLD_TO_VELOCITY (SCALED_ONE) - 1)); + } +#ifdef DEBUG_COLLIDE + GetCurrentVelocityComponents (&ElementPtr0->velocity, &dx0, &dy0); + GetCurrentVelocityComponents (&ElementPtr1->velocity, &dx1, &dy1); + log_add (log_Debug, "After: <%d, %d> <%d, %d>\n", + dx0, dy0, dx1, dy1); +#endif /* DEBUG_COLLIDE */ + } +} + |