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-rw-r--r--engines/agi/checks.cpp320
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diff --git a/engines/agi/checks.cpp b/engines/agi/checks.cpp
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+/* ScummVM - Scumm Interpreter
+ * Copyright (C) 2006 The ScummVM project
+ *
+ * Copyright (C) 1999-2001 Sarien Team
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#include "common/stdafx.h"
+#include "agi/agi.h"
+
+namespace Agi {
+
+static int check_position(struct vt_entry *v) {
+ debugC(4, kDebugLevelSprites, "check position @ %d, %d", v->x_pos, v->y_pos);
+
+ if (v->x_pos < 0 ||
+ v->x_pos + v->x_size > _WIDTH ||
+ v->y_pos - v->y_size + 1 < 0 ||
+ v->y_pos >= _HEIGHT ||
+ ((~v->flags & IGNORE_HORIZON) && v->y_pos <= game.horizon)) {
+ debugC(4, kDebugLevelSprites, "check position failed: x=%d, y=%d, h=%d, w=%d",
+ v->x_pos, v->y_pos, v->x_size, v->y_size);
+ return 0;
+ }
+
+ /* MH1 needs this, but it breaks LSL1 */
+ if (agi_get_release() >= 0x3000) {
+ if (v->y_pos < v->y_size)
+ return 0;
+ }
+
+ return 1;
+}
+
+/**
+ * Check if there's another object on the way
+ */
+static int check_collision(struct vt_entry *v) {
+ struct vt_entry *u;
+
+ if (v->flags & IGNORE_OBJECTS)
+ return 0;
+
+ for (u = game.view_table; u < &game.view_table[MAX_VIEWTABLE]; u++) {
+ if ((u->flags & (ANIMATED | DRAWN)) != (ANIMATED | DRAWN))
+ continue;
+
+ if (u->flags & IGNORE_OBJECTS)
+ continue;
+
+ /* Same object, check next */
+ if (v->entry == u->entry)
+ continue;
+
+ /* No horizontal overlap, check next */
+ if (v->x_pos + v->x_size < u->x_pos ||
+ v->x_pos > u->x_pos + u->x_size)
+ continue;
+
+ /* Same y, return error! */
+ if (v->y_pos == u->y_pos)
+ goto return_1;
+
+ /* Crossed the baseline, return error! */
+ if ((v->y_pos > u->y_pos && v->y_pos2 < u->y_pos2) ||
+ (v->y_pos < u->y_pos && v->y_pos2 > u->y_pos2)) {
+ goto return_1;
+ }
+ }
+
+ return 0;
+
+ return_1:
+ debugC(4, kDebugLevelSprites, "check returns 1 (object %d)", v->entry);
+ return 1;
+}
+
+static int check_priority(struct vt_entry *v) {
+ int i, trigger, water, pass, pri;
+ uint8 *p0;
+
+ if (~v->flags & FIXED_PRIORITY) {
+ /* Priority bands */
+ v->priority = game.pri_table[v->y_pos];
+ }
+
+ trigger = 0;
+ water = 0;
+ pass = 1;
+
+ if (v->priority == 0x0f)
+ goto _check_ego;
+
+ water = 1;
+
+ p0 = &game.sbuf[v->x_pos + v->y_pos * _WIDTH];
+
+ for (i = 0; i < v->x_size; i++, p0++) {
+ pri = *p0 >> 4;
+
+ if (pri == 0) { /* unconditional black. no go at all! */
+ pass = 0;
+ break;
+ }
+
+ if (pri == 3) /* water surface */
+ continue;
+
+ water = 0;
+
+ if (pri == 1) { /* conditional blue */
+ if (v->flags & IGNORE_BLOCKS)
+ continue;
+
+ debugC(4, kDebugLevelSprites, "Blocks observed!");
+ pass = 0;
+ break;
+ }
+
+ if (pri == 2) { /* trigger */
+ debugC(4, kDebugLevelSprites, "stepped on trigger");
+#ifdef USE_CONSOLE
+ if (!debug_.ignoretriggers)
+#endif
+ trigger = 1;
+ }
+ }
+
+ if (pass) {
+ if (!water && v->flags & ON_WATER)
+ pass = 0;
+ if (water && v->flags & ON_LAND)
+ pass = 0;
+ }
+
+ _check_ego:
+ if (v->entry == 0) {
+ setflag(F_ego_touched_p2, trigger ? true : false);
+ setflag(F_ego_water, water ? true : false);
+ }
+
+ return pass;
+}
+
+/*
+ * 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 update_position() {
+ struct vt_entry *v;
+ int x, y, old_x, old_y, border;
+
+ game.vars[V_border_code] = 0;
+ game.vars[V_border_touch_ego] = 0;
+ game.vars[V_border_touch_obj] = 0;
+
+ for (v = game.view_table; v < &game.view_table[MAX_VIEWTABLE]; v++) {
+ if ((v->flags & (ANIMATED | UPDATE | DRAWN)) != (ANIMATED | UPDATE | DRAWN)) {
+ continue;
+ }
+
+ if (v->step_time_count != 0) {
+ if (--v->step_time_count != 0)
+ continue;
+ }
+
+ v->step_time_count = v->step_time;
+
+ x = old_x = v->x_pos;
+ y = old_y = v->y_pos;
+
+ /* If object has moved, update its position */
+ if (~v->flags & UPDATE_POS) {
+ 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 += v->step_size * dx[v->direction];
+ y += v->step_size * dy[v->direction];
+ }
+
+ /* Now check if it touched the borders */
+ border = 0;
+
+ /* Check left/right borders */
+ if (x < 0) {
+ x = 0;
+ border = 4;
+ } else if (x <= 0 && agi_get_release() == 0x3086) { /* KQ4 */
+ x = 0; /* See bug #590462 */
+ border = 4;
+ } else if (v->entry == 0 && x == 0 && v->flags & ADJ_EGO_XY) {
+ /* Extra test to walk west clicking the mouse */
+ x = 0;
+ border = 4;
+ } else if (x + v->x_size > _WIDTH) {
+ x = _WIDTH - v->x_size;
+ border = 2;
+ }
+
+ /* Check top/bottom borders. */
+ if (y - v->y_size + 1 < 0) {
+ y = v->y_size - 1;
+ border = 1;
+ } else if (y > _HEIGHT - 1) {
+ y = _HEIGHT - 1;
+ border = 3;
+ } else if ((~v->flags & IGNORE_HORIZON) && 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 */
+ v->x_pos = x;
+ v->y_pos = y;
+ if (check_collision(v) || !check_priority(v)) {
+ v->x_pos = old_x;
+ v->y_pos = old_y;
+ border = 0;
+ fix_position(v->entry);
+ }
+
+ if (border != 0) {
+ if (v == game.view_table) {
+ game.vars[V_border_touch_ego] = border;
+ } else {
+ game.vars[V_border_code] = v->entry;
+ game.vars[V_border_touch_obj] = border;
+ }
+ if (v->motion == MOTION_MOVE_OBJ) {
+ in_destination(v);
+ }
+ }
+
+ v->flags &= ~UPDATE_POS;
+ }
+}
+
+/**
+ * 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 behaviour is also known as the "Budin-Sonneveld effect".
+ *
+ * @param n view table entry number
+ */
+void fix_position(int n) {
+ struct vt_entry *v = &game.view_table[n];
+ int count, dir, size;
+
+ debugC(4, kDebugLevelSprites, "adjusting view table entry #%d (%d,%d)", n, v->x_pos, v->y_pos);
+
+ /* test horizon */
+ if ((~v->flags & IGNORE_HORIZON) && v->y_pos <= game.horizon)
+ v->y_pos = game.horizon + 1;
+
+ dir = 0;
+ count = size = 1;
+
+ while (!check_position(v) || check_collision(v) || !check_priority(v)) {
+ switch (dir) {
+ case 0: /* west */
+ v->x_pos--;
+ if (--count)
+ continue;
+ dir = 1;
+ break;
+ case 1: /* south */
+ v->y_pos++;
+ if (--count)
+ continue;
+ dir = 2;
+ size++;
+ break;
+ case 2: /* east */
+ v->x_pos++;
+ if (--count)
+ continue;
+ dir = 3;
+ break;
+ case 3: /* north */
+ v->y_pos--;
+ if (--count)
+ continue;
+ dir = 0;
+ size++;
+ break;
+ }
+
+ count = size;
+ }
+
+ debugC(4, kDebugLevelSprites, "view table entry #%d position adjusted to (%d,%d)", n, v->x_pos, v->y_pos);
+}
+
+} // End of namespace Agi
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