scummvm/engines/agi/checks.cpp
2021-12-26 18:48:43 +01:00

352 lines
9.3 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
#include "agi/agi.h"
#include "agi/graphics.h"
namespace Agi {
bool AgiEngine::checkPosition(ScreenObjEntry *screenObj) {
bool result = true; // position is fine
debugC(4, kDebugLevelSprites, "check position @ %d, %d", screenObj->xPos, screenObj->yPos);
if (screenObj->xPos < 0) {
result = false;
} else {
if (screenObj->xPos + screenObj->xSize > SCRIPT_WIDTH) {
result = false;
} else {
if (screenObj->yPos - screenObj->ySize < -1) {
result = false;
} else {
if (screenObj->yPos >= SCRIPT_HEIGHT) {
result = false;
} else {
if (((!(screenObj->flags & fIgnoreHorizon)) && screenObj->yPos <= _game.horizon)) {
result = false;
}
}
}
}
}
// MH1 needs this, but it breaks LSL1
// TODO: *NOT* in disassembly of AGI3 .149, why was this needed?
// if (getVersion() >= 0x3000) {
// if (screenObj->yPos < screenObj->ySize)
// result = false;
// }
if (!result) {
debugC(4, kDebugLevelSprites, "check position failed: x=%d, y=%d, h=%d, w=%d",
screenObj->xPos, screenObj->yPos, screenObj->xSize, screenObj->ySize);
}
return result;
}
/**
* Check if there's another object on the way
*/
bool AgiEngine::checkCollision(ScreenObjEntry *screenObj) {
ScreenObjEntry *checkObj;
if (screenObj->flags & fIgnoreObjects)
return false;
for (checkObj = _game.screenObjTable; checkObj < &_game.screenObjTable[SCREENOBJECTS_MAX]; checkObj++) {
if ((checkObj->flags & (fAnimated | fDrawn)) != (fAnimated | fDrawn))
continue;
if (checkObj->flags & fIgnoreObjects)
continue;
// Same object, check next
if (screenObj->objectNr == checkObj->objectNr)
continue;
// No horizontal overlap, check next
if (screenObj->xPos + screenObj->xSize < checkObj->xPos || screenObj->xPos > checkObj->xPos + checkObj->xSize)
continue;
// Same y, return error!
if (screenObj->yPos == checkObj->yPos) {
debugC(4, kDebugLevelSprites, "check returns 1 (object %d)", screenObj->objectNr);
return true;
}
// Crossed the baseline, return error!
if ((screenObj->yPos > checkObj->yPos && screenObj->yPos_prev < checkObj->yPos_prev) ||
(screenObj->yPos < checkObj->yPos && screenObj->yPos_prev > checkObj->yPos_prev)) {
debugC(4, kDebugLevelSprites, "check returns 1 (object %d)", screenObj->objectNr);
return true;
}
}
return false;
}
bool AgiEngine::checkPriority(ScreenObjEntry *screenObj) {
bool touchedWater = false;
bool touchedTrigger = false;
bool touchedControl = true;
int16 curX;
int16 curY;
int16 celX;
byte screenPriority = 0;
if (!(screenObj->flags & fFixedPriority)) {
// Priority bands
screenObj->priority = _gfx->priorityFromY(screenObj->yPos);
}
if (screenObj->priority != 0x0f) {
touchedWater = true;
curX = screenObj->xPos;
curY = screenObj->yPos;
for (celX = 0; celX < screenObj->xSize; celX++, curX++) {
screenPriority = _gfx->getPriority(curX, curY);
if (screenPriority == 0) { // unconditional black. no go at all!
touchedControl = false;
break;
}
if (screenPriority != 3) { // not water surface
touchedWater = false;
if (screenPriority == 1) { // conditional blue
if (!(screenObj->flags & fIgnoreBlocks)) {
debugC(4, kDebugLevelSprites, "Blocks observed!");
touchedControl = false;
break;
}
} else if (screenPriority == 2) {
debugC(4, kDebugLevelSprites, "stepped on trigger");
if (!_debug.ignoretriggers)
touchedTrigger = true;
}
}
}
if (touchedControl) {
if (!touchedWater) {
if (screenObj->flags & fOnWater)
touchedControl = false;
} else {
if (screenObj->flags & fOnLand)
touchedControl = false;
}
}
}
// Check ego
if (screenObj->objectNr == 0) {
setFlag(VM_FLAG_EGO_TOUCHED_P2, touchedTrigger ? true : false);
setFlag(VM_FLAG_EGO_WATER, touchedWater ? true : false);
}
return touchedControl;
}
/*
* Public functions
*/
/**
* Update position of objects
* This function updates the position of all animated, updating view
* table entries according to its motion type, step size, etc. The
* new position must be valid according to the sprite positioning
* rules, otherwise the previous position will be kept.
*/
void AgiEngine::updatePosition() {
ScreenObjEntry *screenObj;
int x, y, oldX, oldY, border;
setVar(VM_VAR_BORDER_CODE, 0);
setVar(VM_VAR_BORDER_TOUCH_EGO, 0);
setVar(VM_VAR_BORDER_TOUCH_OBJECT, 0);
for (screenObj = _game.screenObjTable; screenObj < &_game.screenObjTable[SCREENOBJECTS_MAX]; screenObj++) {
if ((screenObj->flags & (fAnimated | fUpdate | fDrawn)) != (fAnimated | fUpdate | fDrawn)) {
continue;
}
if (screenObj->stepTimeCount > 1) {
screenObj->stepTimeCount--;
continue;
}
screenObj->stepTimeCount = screenObj->stepTime;
x = oldX = screenObj->xPos;
y = oldY = screenObj->yPos;
// If object has moved, update its position
if (!(screenObj->flags & fUpdatePos)) {
int dx[9] = { 0, 0, 1, 1, 1, 0, -1, -1, -1 };
int dy[9] = { 0, -1, -1, 0, 1, 1, 1, 0, -1 };
x += screenObj->stepSize * dx[screenObj->direction];
y += screenObj->stepSize * dy[screenObj->direction];
}
// Now check if it touched the borders
border = 0;
// Check left/right borders
if (getVersion() == 0x3086) {
// KQ4 interpreter does a different comparison on x
// The interpreter before (2.917) and after that (3.098) don't do them that way
// This difference is required for at least Sarien bug #192
// KQ4: room 135, hen moves from the center of the screen to the left border,
// but it doesn't disappear.
if (x <= 0) {
x = 0;
border = 4;
}
} else {
// regular comparison
if (x < 0) {
x = 0;
border = 4;
}
}
// } else if (v->entry == 0 && x == 0 && v->flags & fAdjEgoXY) { // should not be required
// // Extra test to walk west clicking the mouse
// x = 0;
// border = 4;
if (!border) {
if (x + screenObj->xSize > SCRIPT_WIDTH) {
x = SCRIPT_WIDTH - screenObj->xSize;
border = 2;
}
}
// Check top/bottom borders.
if (y - screenObj->ySize < -1) {
y = screenObj->ySize - 1;
border = 1;
} else if (y > SCRIPT_HEIGHT - 1) {
y = SCRIPT_HEIGHT - 1;
border = 3;
} else if ((!(screenObj->flags & fIgnoreHorizon)) && y <= _game.horizon) {
debugC(4, kDebugLevelSprites, "y = %d, horizon = %d", y, _game.horizon);
y = _game.horizon + 1;
border = 1;
}
// Test new position. rollback if test fails
screenObj->xPos = x;
screenObj->yPos = y;
if (checkCollision(screenObj) || !checkPriority(screenObj)) {
screenObj->xPos = oldX;
screenObj->yPos = oldY;
border = 0;
fixPosition(screenObj->objectNr);
}
if (border) {
if (isEgoView(screenObj)) {
setVar(VM_VAR_BORDER_TOUCH_EGO, border);
} else {
setVar(VM_VAR_BORDER_CODE, screenObj->objectNr);
setVar(VM_VAR_BORDER_TOUCH_OBJECT, border);
}
if (screenObj->motionType == kMotionMoveObj) {
motionMoveObjStop(screenObj);
}
}
screenObj->flags &= ~fUpdatePos;
}
}
/**
* Adjust position of a sprite
* This function adjusts the position of a sprite moving it until
* certain criteria is matched. According to priority and control line
* data, a sprite may not always appear at the location we specified.
* This behavior is also known as the "Budin-Sonneveld effect".
*
* @param n view table entry number
*/
void AgiEngine::fixPosition(int16 screenObjNr) {
ScreenObjEntry *screenObj = &_game.screenObjTable[screenObjNr];
fixPosition(screenObj);
}
void AgiEngine::fixPosition(ScreenObjEntry *screenObj) {
int count, dir, size;
debugC(4, kDebugLevelSprites, "adjusting view table entry #%d (%d,%d)", screenObj->objectNr, screenObj->xPos, screenObj->yPos);
// test horizon
if ((!(screenObj->flags & fIgnoreHorizon)) && screenObj->yPos <= _game.horizon)
screenObj->yPos = _game.horizon + 1;
dir = 0;
count = size = 1;
while (!checkPosition(screenObj) || checkCollision(screenObj) || !checkPriority(screenObj)) {
switch (dir) {
case 0: // west
screenObj->xPos--;
if (--count)
continue;
dir = 1;
break;
case 1: // south
screenObj->yPos++;
if (--count)
continue;
dir = 2;
size++;
break;
case 2: // east
screenObj->xPos++;
if (--count)
continue;
dir = 3;
break;
case 3: // north
screenObj->yPos--;
if (--count)
continue;
dir = 0;
size++;
break;
default:
break;
}
count = size;
}
debugC(4, kDebugLevelSprites, "view table entry #%d position adjusted to (%d,%d)", screenObj->objectNr, screenObj->xPos, screenObj->yPos);
}
} // End of namespace Agi