game.c

   1 #include <stdio.h>
   2 #include <math.h>
   3
   4 #include <SDL/SDL.h>
   5
   6 #include "tennix.h"
   7 #include "game.h"
   8 #include "graphics.h"
   9 #include "input.h"
  10 #include "sound.h"
  11
  12 typedef struct {
  13     float x;
  14     float y;
  15     float move_x;
  16     float move_y;
  17     float jump;
  18 } Ball;
  19
  20 typedef struct {
  21     float x;
  22     float y;
  23     unsigned char state;
  24     unsigned int score;
  25     unsigned char responsible; /* responsible for the next fault (if any) */
  26 } Player;
  27
  28 void game() {
  29     int i;
  30     float phase;
  31     int ground_state = 0;
  32
  33     Ball ball = { GAME_X_MID, GAME_Y_MID, BALL_DEFAULT_SPEED, 0.2, 7.5 };
  34     Ball ground = { 0, 0, 0, 0, 0 };
  35     Player player1 = { GAME_X_MIN-4, GAME_Y_MID, 0, 0, 1 };
  36     Player player2 = { GAME_X_MAX, GAME_Y_MID, 0, 0, 0 };
  37
  38     Uint8 *keys;
  39     SDL_Event e;
  40
  41     clearscr();
  42     updatescr();
  43     wait_keypress();
  44
  45     sound_audience();
  46
  47     while( 1) {
  48         clearscr();
  49         show_bmp( "data/court.bmp", 0, 0, 255);
  50         show_bmp( "data/shadow.png", ball.x, ball.y, 255);
  51
  52         show_sprite( RACKET_BMP, (!player1.state), 4, player1.x, player1.y, 255);
  53         show_sprite( RACKET_BMP, (!player2.state)+2, 4, player2.x, player2.y, 255);
  54
  55         phase = 2*1.6*ball.jump*get_phase( ball.x, GAME_X_MIN, GAME_X_MAX, ball.move_x);
  56         if( phase < 1.0) {
  57             if( !ground_state) {
  58                 sound_ground();
  59                 /* after the ball hit the ground, responsibilities change */
  60                 player1.responsible = !(player2.responsible = !player2.responsible);
  61             }
  62             ground_state = 1;
  63             ground.jump = 3;
  64             ground.x = ball.x;
  65             ground.y = ball.y;
  66         } else {
  67             ground_state = 0;
  68             if( ground.jump && !(i%5)) ground.jump--;
  69         }
  70
  71         if( ground.jump) {
  72             show_sprite( "data/ground.png", ground.jump-1, 3, ground.x, ground.y, 128);
  73         }
  74
  75         if( ball.move_x > 0) {
  76             show_sprite( "data/ball.png", (i/5)%4, 4, ball.x, ball.y-phase, 255);
  77         } else {
  78             show_sprite( "data/ball.png", 3-(i/5)%4, 4, ball.x, ball.y-phase, 255);
  79         }
  80
  81         show_digit( player1.score/10%10, 140*2, 14, 100);
  82         show_digit( player1.score%10, 148*2, 14, 100);
  83         show_digit( 10, 156*2, 14, 100);
  84         show_digit( player2.score/10%10, 164*2, 14, 100);
  85         show_digit( player2.score%10, 172*2, 14, 100);
  86
  87         updatescr();
  88
  89         if( IS_OUT_X(ball.x) || IS_OUT_Y(ball.y)) {
  90             if( (IS_OUT_Y(ball.y) && player1.responsible) || (!(player1.state && IS_NEAR_Y(player1.y, ball.y+phase)) && ball.x < GAME_X_MIN)) {
  91                 player2.score++;
  92                 sound_applause();
  93                 player2.responsible = !(player1.responsible = 1);
  94                 ball.x = GAME_X_MID;
  95                 ball.y = GAME_Y_MID;
  96                 ball.move_x = fabsf( ball.move_x);
  97                 limit_value( &ball.move_x, ball.move_x, BALL_DEFAULT_SPEED);
  98                 ball.move_y = -0.1;
  99                 wait_keypress();
 100                 sound_applause_stop();
 101             }
 102
 103             if( (IS_OUT_Y(ball.y) && player2.responsible) || (!(player2.state && IS_NEAR_Y(player2.y, ball.y+phase)) && ball.x > GAME_X_MAX)) {
 104                 player1.score++;
 105                 sound_applause();
 106                 player1.responsible = !(player2.responsible = 1);
 107                 ball.x = GAME_X_MID;
 108                 ball.y = GAME_Y_MID;
 109                 ball.move_x = -fabsf( ball.move_x);
 110                 limit_value( &ball.move_x, -BALL_DEFAULT_SPEED, ball.move_x);
 111                 ball.move_y = 0.1;
 112                 wait_keypress();
 113                 sound_applause_stop();
 114             }
 115
 116             if( IS_OUT_X(ball.x)) {
 117                 if( ball.move_x < 0) {
 118                     ball.x = GAME_X_MIN;
 119                     if( player1.state == PLAYER_STATE_MAX) {
 120                         ball.move_x = PLAYER_POWERSHOT;
 121                     } else {
 122                         ball.move_x = 2.5 + 2.0*player1.state/PLAYER_STATE_MAX;
 123                     }
 124                     ball.move_y = get_move_y( player1.y, ball.y-phase, PLAYER_AREA, ball.move_x, phase);
 125                     ball.jump += 1.0-2.0*(player1.state<5);
 126                     sound_racket( player1.state == PLAYER_STATE_MAX);
 127                 } else {
 128                     ball.x = GAME_X_MAX;
 129                     if( player2.state == PLAYER_STATE_MAX) {
 130                         ball.move_x = -PLAYER_POWERSHOT;
 131                     } else {
 132                         ball.move_x = -(2.5 + 2.0*player2.state/PLAYER_STATE_MAX);
 133                     }
 134                     ball.move_y = get_move_y( player2.y, ball.y-phase, PLAYER_AREA, ball.move_x, phase);
 135                     ball.jump += 1.0-2.0*(player2.state<5);
 136                     sound_racket( player2.state == PLAYER_STATE_MAX);
 137                 }
 138             }
 139         }
 140
 141         ball.x += ball.move_x*2;
 142         ball.y += ball.move_y*2;
 143
 144         if( player1.state) player1.state--;
 145         if( player2.state) player2.state--;
 146
 147         SDL_PollEvent( &e);
 148         keys = SDL_GetKeyState( NULL);
 149
 150         if( keys['2']) player1.y-=8;
 151         if( keys['w']) player1.y-=6;
 152         if( keys['s']) player1.y+=6;
 153         if( keys['x']) player1.y+=8;
 154         if( keys['d'] && !player1.state) player1.state = PLAYER_STATE_MAX;
 155
 156         if( keys['9']) player2.y-=8;
 157         if( keys['o']) player2.y-=6;
 158         if( keys['l']) player2.y+=6;
 159         if( keys['.']) player2.y+=8;
 160         if( keys['k'] && !player2.state) player2.state = PLAYER_STATE_MAX;
 161
 162         if( keys['f']) SDL_WM_ToggleFullScreen( screen);
 163
 164         if( keys[SDLK_ESCAPE] || keys['q']) break;
 165
 166         limit_value( &player1.y, PLAYER_Y_MIN, PLAYER_Y_MAX);
 167         limit_value( &player2.y, PLAYER_Y_MIN, PLAYER_Y_MAX);
 168         limit_value( &ball.jump, BALL_JUMP_MIN, BALL_JUMP_MAX);
 169
 170
 171         SDL_Delay( 7);
 172         i++;
 173     }
 174
 175 }
 176
 177 void limit_value( float* value, float min, float max) {
 178     if( *value < min) {
 179         *value = min;
 180     } else if( *value > max) {
 181         *value = max;
 182     }
 183 }
 184
 185 float get_phase( float x, float min, float max, float direction) {
 186     float pos, fract;
 187
 188     pos = (direction>0)?(1-GROUND_PHASE):(GROUND_PHASE);
 189
 190     fract = (x-min)/(max-min);
 191
 192     if( fract < pos) {
 193         fract = fract/pos;
 194         return fabsf( cosf(PI*fract/2));
 195     } else {
 196         fract = (pos-fract)/(1-pos);
 197         return fabsf( sinf(PI*fract/2));
 198     }
 199 }
 200
 201 float get_move_y( float py, float by, float pa, float move_x, float phase) {
 202     float pct, dest, x_len, y_len;
 203
 204     /* 0.0 .. 1.0 for racket hit position */
 205     pct = ((py+pa)-by)/(2*pa);
 206     limit_value( &pct, 0.0, 1.0);
 207
 208     /* Y destination for ball */
 209     dest = GAME_Y_MIN + pct*(GAME_Y_MAX-GAME_Y_MIN);
 210
 211     /* lengths for the ball's journey */
 212     x_len = GAME_X_MAX - GAME_X_MIN;
 213     y_len = dest - py + phase;
 214
 215     /* return the should-be value for move_y */
 216     return (y_len*move_x)/(x_len);
 217 }
 218
 219
 220