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Diffstat (limited to 'sword2/scroll.cpp')
| -rw-r--r-- | sword2/scroll.cpp | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/sword2/scroll.cpp b/sword2/scroll.cpp new file mode 100644 index 0000000000..65148e00f3 --- /dev/null +++ b/sword2/scroll.cpp @@ -0,0 +1,154 @@ +/* Copyright (C) 1994-2003 Revolution Software Ltd + * + * 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. + * + * $Header$ + */ + +//------------------------------------------------------------------------------------ +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> + +//#include "src\driver96.h" +#include "build_display.h" +#include "debug.h" +#include "defs.h" +#include "header.h" +#include "interpreter.h" +#include "layers.h" +#include "memory.h" +#include "object.h" +#include "protocol.h" +#include "resman.h" +#include "scroll.h" + +//------------------------------------------------------------------------------------ +#define MAX_SCROLL_DISTANCE 8 // max no of pixel allowed to scroll per cycle + +//------------------------------------------------------------------------------------ +uint8 scroll_fraction=16; // used to be a define, but now it's flexible (see new functions below) +//------------------------------------------------------------------------------------ +void Set_scrolling(void) //S2.1(2Mar94jel) refurnished Tony25Sept96 :-) +{ + // feet_x = 128+320 // normally we aim to get George's feet at (320,250) from top left of screen window + // feet_y = 128+250 + + // set scroll offsets according to the player's coords + + int16 offset_x; + int16 offset_y; + int16 dx, dy; + uint16 scroll_distance_x; // how much we want to scroll + uint16 scroll_distance_y; + + + if (SCROLL_X || SCROLL_Y) // if the scroll offsets are being forced in script (05feb97 JAMES) + { + // ensure not too far right + if (SCROLL_X < this_screen.max_scroll_offset_x) + this_screen.scroll_offset_x = SCROLL_X; + else + this_screen.scroll_offset_x = this_screen.max_scroll_offset_x; + + // ensure not too far down + if (SCROLL_Y < this_screen.max_scroll_offset_y) + this_screen.scroll_offset_y = SCROLL_Y; + else + this_screen.scroll_offset_y = this_screen.max_scroll_offset_y; + } + else + { + offset_x = this_screen.player_feet_x-this_screen.feet_x; // George's offset from the centre - the desired position for him + offset_y = this_screen.player_feet_y-this_screen.feet_y; + + + // prevent scrolling too far left/right/up/down + offset_x = offset_x < 0 ? 0 : ( (uint32)offset_x > this_screen.max_scroll_offset_x ? this_screen.max_scroll_offset_x : offset_x ); + offset_y = offset_y < 0 ? 0 : ( (uint32)offset_y > this_screen.max_scroll_offset_y ? this_screen.max_scroll_offset_y : offset_y ); + + if (this_screen.scroll_flag==2) // first time on this screen - need absolute scroll immediately! + { + //Zdebug(42,"init scroll"); + this_screen.scroll_offset_x = offset_x; + this_screen.scroll_offset_y = offset_y; + this_screen.scroll_flag=1; + } + else // catch up with required scroll offsets - speed depending on distance to catch up (dx and dy) & 'SCROLL_FRACTION' used + { // but limit to certain number of pixels per cycle (MAX_SCROLL_DISTANCE) + + dx = this_screen.scroll_offset_x - offset_x; + dy = this_screen.scroll_offset_y - offset_y; + + if (dx < 0) // current scroll_offset_x is less than the required value + { + scroll_distance_x = (1+(-dx)/scroll_fraction); // => inc by (fraction of the differnce) NB. dx is -ve, so we subtract dx/SCROLL_FRACTION + this_screen.scroll_offset_x += scroll_distance_x < MAX_SCROLL_DISTANCE ? scroll_distance_x : MAX_SCROLL_DISTANCE; + } + else if (dx > 0) // current scroll_offset_x is greater than the required value + { + scroll_distance_x = (1+dx/scroll_fraction); // => dec by (fraction of the differnce) + this_screen.scroll_offset_x -= scroll_distance_x < MAX_SCROLL_DISTANCE ? scroll_distance_x : MAX_SCROLL_DISTANCE; + } // NB. I'm adding 1 to the result of dx/SCROLL_FRACTION, because it would otherwise + // not scroll at all when dx < SCROLL_FRACTION + if (dy < 0) + { + scroll_distance_y = (1+(-dy)/scroll_fraction); + this_screen.scroll_offset_y += scroll_distance_y < MAX_SCROLL_DISTANCE ? scroll_distance_y : MAX_SCROLL_DISTANCE; + } + else if (dy > 0) + { + scroll_distance_y = (1+dy/scroll_fraction); + this_screen.scroll_offset_y -= scroll_distance_y < MAX_SCROLL_DISTANCE ? scroll_distance_y : MAX_SCROLL_DISTANCE; + } + } + } +} +//------------------------------------------------------------------------------------ +int32 FN_set_scroll_coordinate(int32 *params) //Tony25Sept96 +{ + // set the special scroll offset variables + // call when starting screens and to change the camera within screens + // call AFTER FN_init_background() to override the defaults + // called feet_x and feet_y to retain intelectual compatibility with Sword1 ! + // feet_x & feet_y refer to the physical screen coords where the system will try to maintain George's feet + + // param 0 feet_x value + // param 1 feet_y value + + + this_screen.feet_x = params[0]; + this_screen.feet_y = params[1]; + + + return(IR_CONT); +} +//------------------------------------------------------------------------------------ +//------------------------------------------------------------------------------------ +int32 FN_set_scroll_speed_normal(int32 *params) // James08aug97 +{ + scroll_fraction=16; + + return(IR_CONT); +} +//------------------------------------------------------------------------------------ +int32 FN_set_scroll_speed_slow(int32 *params) // James08aug97 +{ + scroll_fraction=32; + + return(IR_CONT); +} +//------------------------------------------------------------------------------------ + |