Subversion Repositories Games.Prince of Persia

Rev

Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
1 pmbaty 1
/*
2
SDLPoP, a port/conversion of the DOS game Prince of Persia.
3
Copyright (C) 2013-2018  Dávid Nagy
4
 
5
This program is free software: you can redistribute it and/or modify
6
it under the terms of the GNU General Public License as published by
7
the Free Software Foundation, either version 3 of the License, or
8
(at your option) any later version.
9
 
10
This program is distributed in the hope that it will be useful,
11
but WITHOUT ANY WARRANTY; without even the implied warranty of
12
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13
GNU General Public License for more details.
14
 
15
You should have received a copy of the GNU General Public License
16
along with this program.  If not, see <http://www.gnu.org/licenses/>.
17
 
18
The authors of this program may be contacted at http://forum.princed.org
19
*/
20
 
21
#include "common.h"
22
 
23
#ifdef USE_LIGHTING
24
 
25
image_type* lighting_mask = NULL;
26
image_type* screen_overlay = NULL;
27
Uint32 bgcolor;
28
 
29
const char mask_filename[1024] = "data/light.png";
30
const Uint8 ambient_level = 128;
31
 
32
// Called once at startup.
33
void init_lighting() {
34
        if (!enable_lighting) return;
35
 
36
        lighting_mask = IMG_Load(mask_filename);
37
        if (lighting_mask == NULL) {
38
                sdlperror("IMG_Load (lighting_mask)");
39
                enable_lighting = 0;
40
                return;
41
        }
42
 
43
        screen_overlay = SDL_CreateRGBSurface(0, 320, 192, 32, 0xFF << 0, 0xFF << 8, 0xFF << 16, 0xFF << 24);
44
        if (screen_overlay == NULL) {
45
                sdlperror("SDL_CreateRGBSurface (screen_overlay)");
46
                enable_lighting = 0;
47
                return;
48
        }
49
 
50
        // "color modulate", i.e. multiply.
51
        int result = SDL_SetSurfaceBlendMode(screen_overlay, SDL_BLENDMODE_MOD);
52
        if (result != 0) {
53
                sdlperror("SDL_SetSurfaceBlendMode (screen_overlay)");
54
        }
55
 
56
        result = SDL_SetSurfaceBlendMode(lighting_mask, SDL_BLENDMODE_ADD);
57
        if (result != 0) {
58
                sdlperror("SDL_SetSurfaceBlendMode (lighting_mask)");
59
        }
60
 
61
        // ambient lighting
62
        bgcolor = SDL_MapRGBA(screen_overlay->format, ambient_level, ambient_level, ambient_level, SDL_ALPHA_OPAQUE);
63
}
64
 
65
// Recreate the lighting overlay based on the torches in the current room.
66
// Called when the current room changes.
67
void redraw_lighting() {
68
        if (!enable_lighting) return;
69
        if (lighting_mask == NULL) return;
70
        if (curr_room_tiles == NULL) return;
71
        if (is_cutscene) return;
72
 
73
        int result = SDL_FillRect(screen_overlay, NULL, bgcolor);
74
        if (result != 0) {
75
                sdlperror("SDL_FillRect (screen_overlay)");
76
        }
77
 
78
        // TODO: Also process nearby offscreen torches?
79
        for (int tile_pos = 0; tile_pos < 30; tile_pos++) {
80
                int tile_type = curr_room_tiles[tile_pos] & 0x1F;
81
                if (tile_type == tiles_19_torch || tile_type == tiles_30_torch_with_debris) {
82
                        // Center of the flame.
83
                        int x = (tile_pos%10)*32+48;
84
                        int y = (tile_pos/10)*63+22;
85
 
86
                        // Align the center of lighting mask to the center of the flame.
87
                        SDL_Rect dest_rect;
88
                        dest_rect.x = x - lighting_mask->w / 2;
89
                        dest_rect.y = y - lighting_mask->h / 2;
90
                        dest_rect.w = lighting_mask->w;
91
                        dest_rect.h = lighting_mask->h;
92
 
93
                        int result = SDL_BlitSurface(lighting_mask, NULL, screen_overlay, &dest_rect);
94
                        if (result != 0) {
95
                                sdlperror("SDL_BlitSurface (lighting_mask)");
96
                        }
97
                }
98
        }
99
        if (upside_down) {
100
                flip_screen(screen_overlay);
101
        }
102
}
103
 
104
// Copy a part of the lighting overlay onto the screen.
105
// Called when the screen is updated.
106
void update_lighting(const rect_type far *target_rect_ptr) {
107
        if (!enable_lighting) return;
108
        if (lighting_mask == NULL) return;
109
        if (curr_room_tiles == NULL) return;
110
        if (is_cutscene) return;
111
 
112
        SDL_Rect sdlrect;
113
        rect_to_sdlrect(target_rect_ptr, &sdlrect);
114
        int result = SDL_BlitSurface(screen_overlay, &sdlrect, onscreen_surface_, &sdlrect);
115
        if (result != 0) {
116
                sdlperror("SDL_BlitSurface (screen_overlay)");
117
        }
118
}
119
 
120
#endif // USE_LIGHTING