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This thread is locked; no one can reply to it.
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| Question on increasing "render" speed |
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djtschke
Member #13,116
August 2011
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Hello everbody, I am quite new to C++ and Allegro and started by following this tutorial Demoscene C++ Allegro Tutorial. I was even able to convert the code to Allegro Version 5 and everything worked fine. Then I started on the task with the snow piling up (at the bottom part of the Tutorial). After a while I also managed to solve this task. Now my problem is that the application is running very slow as you will see if you compile it by yourself. I guess this is because I am working with a Bitmap. My question now is how can I speed up the whole application ? Here is the code: 1#include <stdio.h>
2#include <math.h>
3#include <allegro5/allegro.h>
4
5using namespace std;
6
7// data structures for snow flaxes = very simple
8const int total_flakes=900;
9const int total_layers=3;
10
11struct particle
12{
13 int x,y;
14 int layer;
15};
16
17// global data - okay for a simple example like this
18particle flakes[total_flakes];
19particle lyingFlakes[total_flakes];
20
21// This function initalizes the particle flakes
22void initalize_particle_flakes(void)
23{
24 int i;
25 for (i=0;i<total_flakes;i++)
26 {
27 flakes[i].x=rand()%320; // 0-319 [x]
28 flakes[i].y=rand()%200; // 0-199 [y]
29 flakes[i].layer=rand()%total_layers;// [0-2] [layer]
30
31 lyingFlakes[i].x = ceilf((i / 2.8125));
32 lyingFlakes[i].y = 199;
33 }
34}
35
36void check_for_piling(ALLEGRO_DISPLAY *display, ALLEGRO_BITMAP *haufen) {
37 for (int i=0;i<total_flakes;i++)
38 {
39 ALLEGRO_COLOR particelColor = al_map_rgb(255,255,255);
40 ALLEGRO_COLOR pixelColor = al_get_pixel(haufen,flakes[i].x, flakes[i].y);
41
42 if((particelColor.r == pixelColor.r) && (particelColor.g == pixelColor.g) && (particelColor.b == pixelColor.b)) {
43 // if((flakes[i].y >= 199)) {
44 al_set_target_bitmap(haufen);
45 al_put_pixel(flakes[i].x, (flakes[i].y - 1), particelColor);
46 al_set_target_bitmap(al_get_backbuffer(display));
47 al_draw_bitmap(haufen, 0.0, 0.0, 0);
48 al_flip_display();
49 // }
50 }
51 }
52}
53
54// This function draws all the particle flakes
55void draw_particle_flakes(ALLEGRO_DISPLAY *display)
56{
57 int i;
58
59 for (i=0;i<total_flakes;i++)
60 {
61 al_put_pixel(flakes[i].x, flakes[i].y, al_map_rgb(255,255,255));
62 }
63}
64
65// This updates the particle flakes
66void update_particle_flakes(ALLEGRO_DISPLAY *display)
67{
68 int i;
69
70 for (i=0;i<total_flakes;i++)
71 {
72 ALLEGRO_COLOR pixelColor = al_get_pixel(al_get_backbuffer(display),flakes[i].x, flakes[i].y);
73 ALLEGRO_COLOR particelColor = al_map_rgb(255,255,255);
74
75 // drop the particle down - depending on layer
76 // [plus one - since layer zero would result
77 // in no motion otherwize]
78 flakes[i].y+=flakes[i].layer+1;
79
80 // check for wrap around
81 if (flakes[i].y>199)
82 {
83 flakes[i].x=rand()%320;
84 flakes[i].y=0;
85 flakes[i].layer=rand()%total_layers;
86 }
87
88 // new x position
89 flakes[i].x=(flakes[i].x+(2-rand()%5)) % 320;
90 }
91}
92
93void update_display(ALLEGRO_DISPLAY *display) {
94 update_particle_flakes(display);
95 al_clear_to_color(al_map_rgb(0,0,0));
96 draw_particle_flakes(display);
97 al_flip_display();
98}
99
100// main program
101int main(int argc, char *argv[]) {
102 int i;
103
104 al_init(); // init Allegro
105 al_install_keyboard(); // setup allegro keyboard
106
107 ALLEGRO_DISPLAY *display = NULL;
108 display = al_create_display(320, 200);
109
110 ALLEGRO_BITMAP *haufen = NULL;
111 haufen = al_create_bitmap(320, 200);
112
113 ALLEGRO_EVENT_QUEUE *event_queue = NULL;
114 event_queue = al_create_event_queue();
115
116 al_register_event_source(event_queue, al_get_display_event_source(display));
117
118 ALLEGRO_EVENT ev;
119 ALLEGRO_TIMEOUT timeout;
120 al_init_timeout(&timeout, 0.06);
121
122 bool got_event = al_wait_for_event_until(event_queue, &ev, &timeout);
123
124 ALLEGRO_COLOR white = al_map_rgb(255,255,255);
125
126 initalize_particle_flakes();
127
128 al_set_target_bitmap(haufen);
129 for (i=0;i<total_flakes;i++) {
130 al_put_pixel(lyingFlakes[i].x, lyingFlakes[i].y, al_map_rgb(255,255,255));
131 }
132 al_set_target_bitmap(al_get_backbuffer(display));
133 al_draw_bitmap(haufen, 0.0, 0.0, 0);
134 al_flip_display();
135
136 while (true) {
137 update_display(display);
138 check_for_piling(display, haufen);
139 };
140
141 return 0;
142}
best regards and many thanks for any help ! djtschke |
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jmasterx
Member #11,410
October 2009
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Putting pixels is expensive in A5 and likely your bottleneck. Look into bitmap locking or blit your particle to a bitmap then draw that bitmap instead with al_hold_bitmap_drawing set to true. Agui GUI API -> https://github.com/jmasterx/Agui |
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djtschke
Member #13,116
August 2011
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I already looked into the al_lock_bitmap() function and experimented a bit. But it didn't really help anything. Also I must confess I didn't quite get the clue of how that function works. best regards, djtschke |
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jmasterx
Member #11,410
October 2009
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Then try the other method. create a new bitmap, set it as the target bitmap, draw your pattern, then set the target back to the back buffer, now instead of calls to al_draw_pixel, right before the for loop call: al_hold_bitmap_drawing(true); then in your for loop, draw the bitmap. al_hold_bitmap_drawing(false); Agui GUI API -> https://github.com/jmasterx/Agui |
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SiegeLord
Member #7,827
October 2006
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Try al_draw_prim with ALLEGRO_PRIM_POINT_LIST and a custom vertex declaration (see ex_prim example). "For in much wisdom is much grief: and he that increases knowledge increases sorrow."-Ecclesiastes 1:18 |
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North~
Member #12,192
August 2010
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A bit off-topic but that's a horrible gap in the tutorial I see. It goes from basically the smallest possible allegro program to a slightly extensive particle snow tutorial. -------------------------------------------------- If this is possible if you don't correctly initialize memory, it should be a priority of the highest order. |
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weapon_S
Member #7,859
October 2006
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Very much off-topic: Tutorial said: I run my laptop at 60hz, but my PC at 120.
Yesterday I discovered my CRT monitor had a 120Hz mode |
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SiegeLord
Member #7,827
October 2006
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ALLEGRO_VERTEX has a color parameter. Custom vertex declarations also have a method to specify the color. "For in much wisdom is much grief: and he that increases knowledge increases sorrow."-Ecclesiastes 1:18 |
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