Chủ nhiệm Bộ môn Ngô Hữu Phúc ĐỀ CƯƠng chi tiết bài giảNG
tải về 3.11 Mb.
|
- Điều hướng trang này:
- 9.1.1. Installing and Removing the Timer
- 9.1.2 Slowing Down the Program
- 9.1.3 The TimerTest Program
- //timer variables int start; int counter; int ticks; int framerate;
| Bài giảng 9: Thời gian, cơ chế ngắt, đa tiến trình:
Tiết thứ: 26-29 Tuần thứ: 9+10 - Mục đích, yêu cầu: • Nắm được cách tổ chức sự kiện theo thời gian.. • Nắm được cách ngắt 1 game đang chạy. • Làm việc được với nhiều tiến trình. - Hình thức tổ chức dạy học: Lý thuyết, thực hành, tự học, tự nghiên cứu - Thời gian: Lý thuyết, thảo luận: 4t; Thực hành: 3t Tự học, tự nghiên cứu: 8t - Địa điểm: Giảng đường do P2 phân công. - Nội dung chính: Lý thuyết: Here is a breakdown of the major topics: Understanding timers Working with interrupt handlers Using timed game loops 9.1 Timers Timing is critical in a game. Without an accurate means to slow down a game to a fixed rate, the game will be influenced by the speed of the computer running it, adversely affecting gameplay. 9.1.1. Installing and Removing the Timer You must be sure to call install timer before you create any timer routines and also before you display a mouse pointer or play
You can call the remove timer function if you want to remove the timer before the program ends. void remove timer() 9.1.2 Slowing Down the Program You have seen the rest function used frequently in the sample programs in prior chapters, so it should be familiar to you. For reference, here is the declaration: void rest(long time) One feature that I haven’t gone over yet is the rest callback function. Have you noticed that Allegro provides a callback for almost everything it does? This is a fine degree of control seldom found in game development libraries; obviously, Allegro was developed by individuals with a great deal of experience, who had the foresight to include some very useful callback functions. Here is the declaration: void rest callback(long time, void (*callback)()) This function works like rest, but instead of doing nothing, a callback function is called during the delay period so your program can continue working even while timing is in effect to slow the game down. Here’s an example of how you would call the function: //slow the game down rest callback(8, rest1); The rest1 callback function is very simple; it contains no parameters. void rest1(void) { //time to rest, or do some work? } 9.1.3 The TimerTest Program The first section of code includes the defines, structs, and variables. #include #include #include #include "allegro.h" #define MODE GFX AUTODETECT FULLSCREEN #define WIDTH 640 #define HEIGHT 480 #define NUMSPRITES 6 #define BLACK makecol(0,0,0) #define WHITE makecol(255,255,255) //define the sprite structure typedef struct SPRITE { int dir, alive; int x,y; int width,height; int xspeed,yspeed; int xdelay,ydelay; int xcount,ycount; int curframe,maxframe,animdir; int framecount,framedelay; }SPRITE; //variables BITMAP *back; BITMAP *temp; BITMAP *sprite images[10][10]; SPRITE *sprites[10]; BITMAP *buffer; int n, f; //timer variables int start; int counter; int ticks; int framerate; 
Figure 9.1 The TimerTest program animates many sprites over a background scene. The next section of code for the TimerTest program includes the sprite-handling functions updatesprite, warpsprite, grabframe, and loadsprites. void updatesprite(SPRITE *spr) { //update x position if (++spr->xcount > spr->xdelay) { spr->xcount = 0; spr->x += spr->xspeed; } //update y position if (++spr->ycount > spr->ydelay) { spr->ycount = 0; spr->y += spr->yspeed; } //update frame based on animdir if (++spr->framecount > spr->framedelay) { spr->framecount = 0; if (spr->animdir == -1) { if (--spr->curframe < 0) spr->curframe = spr->maxframe; } Timers 415 416 Chapter 11 n Programming the Perfect Game Loop else if (spr->animdir == 1) { if (++spr->curframe > spr->maxframe) spr->curframe = 0; } } } void warpsprite(SPRITE *spr) { //simple screen warping behavior //Allegro takes care of clipping if (spr->x < 0 - spr->width) { spr->x = SCREEN W; } else if (spr->x > SCREEN W) { spr->x = 0 - spr->width; } if (spr->y < 0) { spr->y = SCREEN H - spr->height-1; } else if (spr->y > SCREEN H - spr->height) { spr->y = 0; } } //reuse our friendly tile grabber BITMAP *grabframe(BITMAP *source, int width, int height, int startx, int starty, int columns, int frame) { BITMAP *temp = create bitmap(width,height); int x = startx + (frame % columns) * width; int y = starty + (frame / columns) * height; blit(source,temp,x,y,0,0,width,height); return temp; } void loadsprites(void) { //load dragon sprite temp = load bitmap("dragon.bmp", NULL); for (n=0; n<6; n++) sprite images[0][n] = grabframe(temp,128,64,0,0,3,n); destroy bitmap(temp); //initialize the dragon (sprite 0) sprites[0] = malloc(sizeof(SPRITE)); sprites[0]->x = 500; sprites[0]->y = 0; sprites[0]->width = sprite images[0][0]->w; sprites[0]->height = sprite images[0][0]->h; sprites[0]->xdelay = 1; sprites[0]->ydelay = 0; sprites[0]->xcount = 0; sprites[0]->ycount = 0; sprites[0]->xspeed = -5; sprites[0]->yspeed = 0; sprites[0]->curframe = 0; sprites[0]->maxframe = 5; sprites[0]->framecount = 0; sprites[0]->framedelay = 5; sprites[0]->animdir = 1; //load fish sprite temp = load bitmap("fish.bmp", NULL); for (n=0; n<3; n++) sprite images[1][n] = grabframe(temp,64,32,0,0,3,n); destroy bitmap(temp); //initialize the fish (sprite 1) sprites[1] = malloc(sizeof(SPRITE)); sprites[1]->x = 300; sprites[1]->y = 400; sprites[1]->width = sprite images[1][0]->w; sprites[1]->height = sprite images[1][0]->h; sprites[1]->xdelay = 1; sprites[1]->ydelay = 0; sprites[1]->xcount = 0; sprites[1]->ycount = 0; sprites[1]->xspeed = 3; sprites[1]->yspeed = 0; sprites[1]->curframe = 0; sprites[1]->maxframe = 2; sprites[1]->framecount = 0; sprites[1]->framedelay = 8; sprites[1]->animdir = 1; //load crab sprite temp = load bitmap("crab.bmp", NULL); for (n=0; n<4; n++) sprite images[2][n] = grabframe(temp,64,32,0,0,4,n); destroy bitmap(temp); //initialize the crab (sprite 2) sprites[2] = malloc(sizeof(SPRITE)); sprites[2]->x = 300; sprites[2]->y = 212; sprites[2]->width = sprite images[2][0]->w; sprites[2]->height = sprite images[2][0]->h; sprites[2]->xdelay = 6; sprites[2]->ydelay = 0; sprites[2]->xcount = 0; sprites[2]->ycount = 0; sprites[2]->xspeed = 2; sprites[2]->yspeed = 0; sprites[2]->curframe = 0; sprites[2]->maxframe = 3; sprites[2]->framecount = 0; sprites[2]->framedelay = 20; sprites[2]->animdir = 1; //load bee sprite temp = load bitmap("bee.bmp", NULL); for (n=0; n<6; n++) sprite images[3][n] = grabframe(temp,50,40,0,0,6,n); destroy bitmap(temp); //initialize the crab (sprite 2) sprites[3] = malloc(sizeof(SPRITE)); sprites[3]->x = 100; sprites[3]->y = 120; sprites[3]->width = sprite images[3][0]->w; sprites[3]->height = sprite images[3][0]->h; sprites[3]->xdelay = 1; sprites[3]->ydelay = 0; sprites[3]->xcount = 0; sprites[3]->ycount = 0; sprites[3]->xspeed = -3; sprites[3]->yspeed = 0; sprites[3]->curframe = 0; sprites[3]->maxframe = 5; sprites[3]->framecount = 0; sprites[3]->framedelay = 8; sprites[3]->animdir = 1; //load skeeter sprite temp = load bitmap("skeeter.bmp", NULL); for (n=0; n<6; n++) sprite images[4][n] = grabframe(temp,50,40,0,0,6,n); destroy bitmap(temp); //initialize the crab (sprite 2) sprites[4] = malloc(sizeof(SPRITE)); sprites[4]->x = 500; sprites[4]->y = 70; sprites[4]->width = sprite images[4][0]->w; sprites[4]->height = sprite images[4][0]->h; sprites[4]->xdelay = 1; sprites[4]->ydelay = 0; sprites[4]->xcount = 0; sprites[4]->ycount = 0; sprites[4]->xspeed = 4; sprites[4]->yspeed = 0; sprites[4]->curframe = 0; sprites[4]->maxframe = 4; sprites[4]->framecount = 0; sprites[4]->framedelay = 2; sprites[4]->animdir = 1; //load snake sprite temp = load bitmap("snake.bmp", NULL); for (n=0; n<8; n++) sprite images[5][n] = grabframe(temp,100,50,0,0,4,n); destroy bitmap(temp); //initialize the crab (sprite 2) sprites[5] = malloc(sizeof(SPRITE)); sprites[5]->x = 350; sprites[5]->y = 200; sprites[5]->width = sprite images[5][0]->w; sprites[5]->height = sprite images[5][0]->h; sprites[5]->xdelay = 1; sprites[5]->ydelay = 0; sprites[5]->xcount = 0; sprites[5]->ycount = 0; sprites[5]->xspeed = -2; sprites[5]->yspeed = 0; sprites[5]->curframe = 0; sprites[5]->maxframe = 4; sprites[5]->framecount = 0; sprites[5]->framedelay = 6; sprites[5]->animdir = 1; } The last section of code for the TimerTest program includes the main function int main(void) { //initialize allegro init(); set color depth(16); set gfx mode(MODE, WIDTH, HEIGHT, 0, 0); srand(time(NULL)); install keyboard(); install timer(); //create double buffer buffer = create bitmap(SCREEN W,SCREEN H); //load and draw the blocks back = load bitmap("background.bmp", NULL); blit(back,buffer,0,0,0,0,back->w,back->h); //load and set up sprites loadsprites(); //game loop while (!keypressed()) { //restore the background for (n=0; n blit(back, buffer, sprites[n]->x, sprites[n]->y, sprites[n]->x, sprites[n]->y, sprites[n]->width, sprites[n]->height); //update the sprites for (n=0; n { updatesprite(sprites[n]); warpsprite(sprites[n]); draw sprite(buffer, sprite images[n][sprites[n]->curframe], sprites[n]->x, sprites[n]->y); } Каталог: files -> FileMonHoc FileMonHoc -> NGÂn hàng câu hỏi lập trình cơ BẢn nhóm câu hỏI 2 ĐIỂM FileMonHoc -> CHƯƠng 2 giới thiệu về LÝ thuyết số FileMonHoc -> CÁc hệ MẬt khoá CÔng khai kháC FileMonHoc -> BỘ MÔn duyệt chủ nhiệm Bộ môn FileMonHoc -> Khoa công nghệ thông tin cộng hòa xã HỘi chủ nghĩa việt nam FileMonHoc -> Chủ nhiệm Bộ môn Ngô Thành Long ĐỀ CƯƠng chi tiết bài giảNG FileMonHoc -> Chủ nhiệm Bộ môn Phan Nguyên Hải ĐỀ CƯƠng chi tiết bài giảNG FileMonHoc -> Khoa: CÔng nghệ thông tin cộng hòa xã HỘi chủ nghĩa việt nam FileMonHoc -> MẬt mã khóA ĐỐi xứng lý thuyết cơ bản của Shannon FileMonHoc -> Khoa công nghệ thông tin bài giảng LẬp trình cơ BẢn biên soạn tải về 3.11 Mb. Chia sẻ với bạn bè của bạn:
|