Bonny Ngangu / Mbed 2 deprecated Squash_Project

The present code implements a single player squash game, using joystick to move paddle right or left. And checks the current temperature inside the device.

Dependencies:   2645_I2C_TMP102 2645_Physics_Engine_Example Paddle mbed

main.cpp@0:61128d697217, 2016-05-06 (annotated)

Committer:
bonnyngangu
Date:
Fri May 06 17:03:41 2016 +0000
Revision:
0:61128d697217
Child:
1:fe4ac8f10309
Updating joystick direction to affect paddle movement.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bonnyngangu 0:61128d697217 1 #include "mbed.h"
bonnyngangu 0:61128d697217 2 #include "N5110.h"
bonnyngangu 0:61128d697217 3 #include "Joystick.h"
bonnyngangu 0:61128d697217 4 #include "SDFileSystem.h"
bonnyngangu 0:61128d697217 5
bonnyngangu 0:61128d697217 6 #define BALLRADIUS 2
bonnyngangu 0:61128d697217 7
bonnyngangu 0:61128d697217 8
bonnyngangu 0:61128d697217 9 // VCC, SCE, RST, D/C, MOSI, SCLK, LED
bonnyngangu 0:61128d697217 10 N5110 lcd (PTE26 , PTA0 , PTC4 , PTD0 , PTD2 , PTD1 , PTC3);
bonnyngangu 0:61128d697217 11 // Can also power (VCC) directly from VOUT (3.3 V) -
bonnyngangu 0:61128d697217 12 // Can give better performance due to current limitation from GPIO pin
bonnyngangu 0:61128d697217 13
bonnyngangu 0:61128d697217 14 InterruptIn interrupt_button(PTB18); // interrupt in button.
bonnyngangu 0:61128d697217 15 PwmOut buzzer(PTA2); // buzzer connection to PwmOut.
bonnyngangu 0:61128d697217 16
bonnyngangu 0:61128d697217 17 // Connections to SD card holder on K64F (SPI interface)
bonnyngangu 0:61128d697217 18 SDFileSystem sd(PTE3, PTE1, PTE2, PTE4, "sd"); // MOSI, MISO, SCK, CS
bonnyngangu 0:61128d697217 19
bonnyngangu 0:61128d697217 20 void delete_file(char filename[]);
bonnyngangu 0:61128d697217 21
bonnyngangu 0:61128d697217 22 // function prototypes
bonnyngangu 0:61128d697217 23 void init_ball();
bonnyngangu 0:61128d697217 24 void game_timer_isr();
bonnyngangu 0:61128d697217 25 void BallMove();
bonnyngangu 0:61128d697217 26 void redraw_screen();
bonnyngangu 0:61128d697217 27 void update_physics_engine();
bonnyngangu 0:61128d697217 28 void check_collisions();
bonnyngangu 0:61128d697217 29 void Squash_Court();
bonnyngangu 0:61128d697217 30 void getPaddle();
bonnyngangu 0:61128d697217 31 void PaddleMove();
bonnyngangu 0:61128d697217 32 void updateJoystick();
bonnyngangu 0:61128d697217 33
bonnyngangu 0:61128d697217 34 //bool wall = false;
bonnyngangu 0:61128d697217 35
bonnyngangu 0:61128d697217 36 // Can give better performance due to current limitation from GPIO pin
bonnyngangu 0:61128d697217 37 Ticker game_timer;
bonnyngangu 0:61128d697217 38
bonnyngangu 0:61128d697217 39 // struct used to store 2D vectors
bonnyngangu 0:61128d697217 40 typedef struct vector_t vector_t;
bonnyngangu 0:61128d697217 41 struct vector_t {
bonnyngangu 0:61128d697217 42 float x;
bonnyngangu 0:61128d697217 43 float y;
bonnyngangu 0:61128d697217 44 };
bonnyngangu 0:61128d697217 45
bonnyngangu 0:61128d697217 46 vector_t pos; // ball position
bonnyngangu 0:61128d697217 47 vector_t vel; // ball velocity
bonnyngangu 0:61128d697217 48 vector_t acc; // ball acceleration
bonnyngangu 0:61128d697217 49
bonnyngangu 0:61128d697217 50 float refresh_rate = 25.0; // how often to update display (Hz)
bonnyngangu 0:61128d697217 51 float g_dt = 2.0F/refresh_rate; // global to store time step (F makes it a float, gets rid of compiler warning)
bonnyngangu 0:61128d697217 52 volatile int g_timer_flag = 0;
bonnyngangu 0:61128d697217 53
bonnyngangu 0:61128d697217 54 int scoring = 0;// setting the value of starting score.
bonnyngangu 0:61128d697217 55 int Lhand = 0;// value of the left hand side on y axis.
bonnyngangu 0:61128d697217 56 int Rhand = 0;// value of the right hand side on y axis.
bonnyngangu 0:61128d697217 57 int m = 42 ;
bonnyngangu 0:61128d697217 58 int a;
bonnyngangu 0:61128d697217 59 int width;// left hand side width.
bonnyngangu 0:61128d697217 60 int width2;/// right hand side width.
bonnyngangu 0:61128d697217 61
bonnyngangu 0:61128d697217 62
bonnyngangu 0:61128d697217 63 int main()
bonnyngangu 0:61128d697217 64 {
bonnyngangu 0:61128d697217 65
bonnyngangu 0:61128d697217 66 wait(1.0); // short delay for power settling
bonnyngangu 0:61128d697217 67 lcd.init(); // initialising the display
bonnyngangu 0:61128d697217 68
bonnyngangu 0:61128d697217 69 lcd.printString(" SQUASH!",15,2);
bonnyngangu 0:61128d697217 70 lcd.inverseMode(); // invert colours
bonnyngangu 0:61128d697217 71 lcd.drawLine(41,0,0,23,1);
bonnyngangu 0:61128d697217 72 lcd.drawLine(41,0,83,23,1);
bonnyngangu 0:61128d697217 73 lcd.drawLine(0,23,41,47,1);
bonnyngangu 0:61128d697217 74 lcd.drawLine(83,23,41,47,1);
bonnyngangu 0:61128d697217 75 lcd.refresh();
bonnyngangu 0:61128d697217 76 wait(5.0);
bonnyngangu 0:61128d697217 77 lcd.clear();
bonnyngangu 0:61128d697217 78 lcd.printString("Game starting",5,2);
bonnyngangu 0:61128d697217 79 lcd.normalMode(); // normal colour mode
bonnyngangu 0:61128d697217 80 lcd.setBrightness(0.5); // put LED backlight on 50%
bonnyngangu 0:61128d697217 81
bonnyngangu 0:61128d697217 82 buzzer.period_ms(2.0);
bonnyngangu 0:61128d697217 83 buzzer.pulsewidth_ms(1.9);
bonnyngangu 0:61128d697217 84 getPaddle();
bonnyngangu 0:61128d697217 85 wait(3.0);
bonnyngangu 0:61128d697217 86
bonnyngangu 0:61128d697217 87 calibrateJoystick(); // get centred values of joystick
bonnyngangu 0:61128d697217 88 pollJoystick.attach(&updateJoystick,1.0/10.0); // read joystick 10 times per second
bonnyngangu 0:61128d697217 89
bonnyngangu 0:61128d697217 90 init_ball();
bonnyngangu 0:61128d697217 91 // setup ticker
bonnyngangu 0:61128d697217 92 game_timer.attach(&game_timer_isr,g_dt);
bonnyngangu 0:61128d697217 93
bonnyngangu 0:61128d697217 94 redraw_screen(); // draw initial screen
bonnyngangu 0:61128d697217 95
bonnyngangu 0:61128d697217 96 while (1) {
bonnyngangu 0:61128d697217 97
bonnyngangu 0:61128d697217 98 Squash_Court();
bonnyngangu 0:61128d697217 99 BallMove();
bonnyngangu 0:61128d697217 100 PaddleMove();
bonnyngangu 0:61128d697217 101 }
bonnyngangu 0:61128d697217 102 }
bonnyngangu 0:61128d697217 103
bonnyngangu 0:61128d697217 104 void getPaddle() // setting paddle moving
bonnyngangu 0:61128d697217 105 {
bonnyngangu 0:61128d697217 106 int m = 42 ; // set paddle into origin 42 on X axis.
bonnyngangu 0:61128d697217 107
bonnyngangu 0:61128d697217 108 // drawing the paddle.
bonnyngangu 0:61128d697217 109 lcd.drawLine(m-6,45,m+6,45,1);
bonnyngangu 0:61128d697217 110 lcd.refresh();
bonnyngangu 0:61128d697217 111 }
bonnyngangu 0:61128d697217 112
bonnyngangu 0:61128d697217 113
bonnyngangu 0:61128d697217 114 void PaddleMove()
bonnyngangu 0:61128d697217 115 {
bonnyngangu 0:61128d697217 116 // setting the joystick control.
bonnyngangu 0:61128d697217 117 if (joystick.direction == RIGHT && m > 4) {
bonnyngangu 0:61128d697217 118 //scoring + = 1;// one pixel move for 1 score.
bonnyngangu 0:61128d697217 119 lcd.drawLine(m-6,45,m+6,45,1);
bonnyngangu 0:61128d697217 120 m-=1;// moving a pixel a time.
bonnyngangu 0:61128d697217 121 lcd.refresh();
bonnyngangu 0:61128d697217 122 }
bonnyngangu 0:61128d697217 123
bonnyngangu 0:61128d697217 124 if (joystick.direction == LEFT && m < 78) {
bonnyngangu 0:61128d697217 125 //scoring + = 1;// one pixel move for 1 score.
bonnyngangu 0:61128d697217 126 lcd.drawLine(m-6,45,m+6,45,1);
bonnyngangu 0:61128d697217 127 m+=1;// moving a pixel a time.
bonnyngangu 0:61128d697217 128
bonnyngangu 0:61128d697217 129 lcd.drawLine(m-6,45,m+6,45,1);
bonnyngangu 0:61128d697217 130 lcd.refresh();
bonnyngangu 0:61128d697217 131 }
bonnyngangu 0:61128d697217 132 }
bonnyngangu 0:61128d697217 133
bonnyngangu 0:61128d697217 134 void Squash_Court()
bonnyngangu 0:61128d697217 135 {
bonnyngangu 0:61128d697217 136
bonnyngangu 0:61128d697217 137 lcd.drawRect(0,0,83,47,0); // transparent, just outline
bonnyngangu 0:61128d697217 138 lcd.refresh(); // need to refresh screen after drawing rects
bonnyngangu 0:61128d697217 139
bonnyngangu 0:61128d697217 140 for (int i = 0; i < 84; i++) {
bonnyngangu 0:61128d697217 141
bonnyngangu 0:61128d697217 142 lcd.setPixel(i,24);// at y = 24 pixels (centre)
bonnyngangu 0:61128d697217 143 }
bonnyngangu 0:61128d697217 144
bonnyngangu 0:61128d697217 145 for (int i = 0; i < 84; i++) {
bonnyngangu 0:61128d697217 146
bonnyngangu 0:61128d697217 147 lcd.setPixel(i,16);// // at y = 14 pixels
bonnyngangu 0:61128d697217 148 }
bonnyngangu 0:61128d697217 149
bonnyngangu 0:61128d697217 150 // need to refresh display after setting pixels
bonnyngangu 0:61128d697217 151 lcd.refresh();
bonnyngangu 0:61128d697217 152
bonnyngangu 0:61128d697217 153 }
bonnyngangu 0:61128d697217 154
bonnyngangu 0:61128d697217 155 int SD_card()
bonnyngangu 0:61128d697217 156 {
bonnyngangu 0:61128d697217 157 serial.baud(115200); // full-speed!
bonnyngangu 0:61128d697217 158 serial.printf("#### SD Card Example #####\n");
bonnyngangu 0:61128d697217 159 FILE *fp; // this is our file pointer
bonnyngangu 0:61128d697217 160 wait(1);
bonnyngangu 0:61128d697217 161
bonnyngangu 0:61128d697217 162 // open file for writing ('w') - creates file if it doesn't exist and overwrites
bonnyngangu 0:61128d697217 163 // if it does. If you wish to add a score onto a list, then you can
bonnyngangu 0:61128d697217 164 // append instead 'a'. This will open the file if it exists and start
bonnyngangu 0:61128d697217 165 // writing at the end. It will create the file if it doesn't exist.
bonnyngangu 0:61128d697217 166 fp = fopen("/sd/topscore.txt", "w");
bonnyngangu 0:61128d697217 167 int top_score = 56; // random example
bonnyngangu 0:61128d697217 168
bonnyngangu 0:61128d697217 169 if (fp == NULL) { // if it can't open the file then print error message
bonnyngangu 0:61128d697217 170 serial.printf("Error! Unable to open file!\n");
bonnyngangu 0:61128d697217 171 } else { // opened file so can write
bonnyngangu 0:61128d697217 172 serial.printf("Writing to file....");
bonnyngangu 0:61128d697217 173 fprintf(fp, "%d",top_score); // ensure data type matches
bonnyngangu 0:61128d697217 174 serial.printf("Done.\n");
bonnyngangu 0:61128d697217 175 fclose(fp); // ensure you close the file after writing
bonnyngangu 0:61128d697217 176 }
bonnyngangu 0:61128d697217 177
bonnyngangu 0:61128d697217 178 // now open file for reading
bonnyngangu 0:61128d697217 179 fp = fopen("/sd/topscore.txt", "r");
bonnyngangu 0:61128d697217 180 int stored_top_score = -1; // -1 to demonstrate it has changed after reading
bonnyngangu 0:61128d697217 181
bonnyngangu 0:61128d697217 182 if (fp == NULL) { // if it can't open the file then print error message
bonnyngangu 0:61128d697217 183 serial.printf("Error! Unable to open file!\n");
bonnyngangu 0:61128d697217 184 } else { // opened file so can write
bonnyngangu 0:61128d697217 185 fscanf(fp, "%d",&stored_top_score); // ensure data type matches - note address operator (&)
bonnyngangu 0:61128d697217 186 serial.printf("Read %d from file.\n",stored_top_score);
bonnyngangu 0:61128d697217 187 fclose(fp); // ensure you close the file after reading
bonnyngangu 0:61128d697217 188 }
bonnyngangu 0:61128d697217 189
bonnyngangu 0:61128d697217 190 // for this example, I'll create some numbers to write to file in a big list
bonnyngangu 0:61128d697217 191 // a data logger for example will usually append to a file - at a reading
bonnyngangu 0:61128d697217 192 // at the end rather than creating a new file
bonnyngangu 0:61128d697217 193 fp = fopen("/sd/test.txt", "a");
bonnyngangu 0:61128d697217 194
bonnyngangu 0:61128d697217 195 if (fp == NULL) { // if it can't open the file then print error message
bonnyngangu 0:61128d697217 196 serial.printf("Error! Unable to open file!\n");
bonnyngangu 0:61128d697217 197 } else { // opened file so can write
bonnyngangu 0:61128d697217 198 serial.printf("Writing to file....");
bonnyngangu 0:61128d697217 199 for(int i = 1; i <= 50; i++) {
bonnyngangu 0:61128d697217 200 float dummy = 1000.0F/i; // dummy variable
bonnyngangu 0:61128d697217 201 fprintf(fp, "%d,%f\n",i,dummy); // print formatted string to file (CSV)
bonnyngangu 0:61128d697217 202 }
bonnyngangu 0:61128d697217 203 serial.printf("Done.\n");
bonnyngangu 0:61128d697217 204 fclose(fp); // ensure you close the file after writing
bonnyngangu 0:61128d697217 205 }
bonnyngangu 0:61128d697217 206
bonnyngangu 0:61128d697217 207 // you can comment out the writing example to check that the writing has
bonnyngangu 0:61128d697217 208 // worked - when you run it after commenting, it should still open the
bonnyngangu 0:61128d697217 209 // file that exists on the SD card - assuming you didn't delete it!
bonnyngangu 0:61128d697217 210
bonnyngangu 0:61128d697217 211 // now open file for reading...note the 'r'
bonnyngangu 0:61128d697217 212 fp = fopen("/sd/test.txt", "r");
bonnyngangu 0:61128d697217 213 if (fp == NULL) { // if it can't open the file then print error message
bonnyngangu 0:61128d697217 214 serial.printf("Error! Unable to open file!\n");
bonnyngangu 0:61128d697217 215 } else {
bonnyngangu 0:61128d697217 216 serial.printf("Reading file....\n");
bonnyngangu 0:61128d697217 217 int i; // create suitable variables to store the data in the file
bonnyngangu 0:61128d697217 218 float value;
bonnyngangu 0:61128d697217 219
bonnyngangu 0:61128d697217 220 // in this example, we keep reading (using fscanf) until we reach
bonnyngangu 0:61128d697217 221 // the 'end of file'. Note we use the address operator & to write
bonnyngangu 0:61128d697217 222 // to the variables. Also the format of the string must match what
bonnyngangu 0:61128d697217 223 // is in the file
bonnyngangu 0:61128d697217 224 while (fscanf(fp, "%d,%f", &i, &value) != EOF) {
bonnyngangu 0:61128d697217 225 serial.printf("%d,%f\n",i,value);
bonnyngangu 0:61128d697217 226 }
bonnyngangu 0:61128d697217 227 serial.printf("Done.\n");
bonnyngangu 0:61128d697217 228 fclose(fp); // ensure you close the file after reading
bonnyngangu 0:61128d697217 229 }
bonnyngangu 0:61128d697217 230
bonnyngangu 0:61128d697217 231 // the previous example just read the values into variables and printed to
bonnyngangu 0:61128d697217 232 // serial, we'll now read files into an array.
bonnyngangu 0:61128d697217 233
bonnyngangu 0:61128d697217 234 // now open file for reading...note the 'r'
bonnyngangu 0:61128d697217 235 fp = fopen("/sd/test.txt", "r");
bonnyngangu 0:61128d697217 236
bonnyngangu 0:61128d697217 237 int n=0; // going to store the number of lines in the file
bonnyngangu 0:61128d697217 238 int *index_array; // pointers to create dynamic arrays later
bonnyngangu 0:61128d697217 239 float *value_array; // note memory will be in heap rather than on the stack
bonnyngangu 0:61128d697217 240
bonnyngangu 0:61128d697217 241 if (fp == NULL) { // if it can't open the file then print error message
bonnyngangu 0:61128d697217 242 serial.printf("Error! Unable to open file!\n");
bonnyngangu 0:61128d697217 243 } else {
bonnyngangu 0:61128d697217 244 serial.printf("Counting lines in file....\n");
bonnyngangu 0:61128d697217 245 //Since we may not know the
bonnyngangu 0:61128d697217 246 // number of lines in the files ahead of time, we'll first count them
bonnyngangu 0:61128d697217 247 // * means scan but don't save
bonnyngangu 0:61128d697217 248 while (fscanf(fp, "%*d,%*f") != EOF) {
bonnyngangu 0:61128d697217 249 n++; // increment counter when read a line
bonnyngangu 0:61128d697217 250 }
bonnyngangu 0:61128d697217 251
bonnyngangu 0:61128d697217 252
bonnyngangu 0:61128d697217 253 serial.printf("Read %d lines\n",n);
bonnyngangu 0:61128d697217 254 serial.printf("Creating dynamic arrays...\n");
bonnyngangu 0:61128d697217 255 // calloc creates an array and initilises to 0
bonnyngangu 0:61128d697217 256 // malloc returns unitialised array - diffrent syntax
bonnyngangu 0:61128d697217 257 index_array = (int *)calloc(n, sizeof (int));
bonnyngangu 0:61128d697217 258 value_array = (float *)calloc(n, sizeof (float));
bonnyngangu 0:61128d697217 259
bonnyngangu 0:61128d697217 260 int i=0;
bonnyngangu 0:61128d697217 261 rewind(fp); // 'scrolled' to end of file, so go back to beginning
bonnyngangu 0:61128d697217 262 serial.printf("Reading into arrays...\n");
bonnyngangu 0:61128d697217 263 while (fscanf(fp, "%d,%f",&index_array[i],&value_array[i]) != EOF) {
bonnyngangu 0:61128d697217 264 i++; // read data into array and increment index
bonnyngangu 0:61128d697217 265 }
bonnyngangu 0:61128d697217 266 serial.printf("Done.\n");
bonnyngangu 0:61128d697217 267 fclose(fp); // ensure you close the file after reading
bonnyngangu 0:61128d697217 268 }
bonnyngangu 0:61128d697217 269
bonnyngangu 0:61128d697217 270 // we should now have the data in the arrays, will print to serial to check
bonnyngangu 0:61128d697217 271 for(int i=0; i<n ; i++) {
bonnyngangu 0:61128d697217 272 serial.printf("[%d] %d,%f\n",i,index_array[i],value_array[i]);
bonnyngangu 0:61128d697217 273 }
bonnyngangu 0:61128d697217 274
bonnyngangu 0:61128d697217 275 serial.printf("End of SD card example\n");
bonnyngangu 0:61128d697217 276
bonnyngangu 0:61128d697217 277 return 0;
bonnyngangu 0:61128d697217 278
bonnyngangu 0:61128d697217 279 }
bonnyngangu 0:61128d697217 280
bonnyngangu 0:61128d697217 281 void delete_file(char filename[])
bonnyngangu 0:61128d697217 282 {
bonnyngangu 0:61128d697217 283 serial.printf("Deleting file '%s'...",filename);
bonnyngangu 0:61128d697217 284 FILE *fp = fopen(filename, "r"); // try and open file
bonnyngangu 0:61128d697217 285 if (fp != NULL) { // if it does open...
bonnyngangu 0:61128d697217 286 fclose(fp); // close it
bonnyngangu 0:61128d697217 287 remove(filename); // and then delete
bonnyngangu 0:61128d697217 288 serial.printf("Done!\n");
bonnyngangu 0:61128d697217 289 }
bonnyngangu 0:61128d697217 290 // if we can't open it, it doesn't exist and so we can't delete it
bonnyngangu 0:61128d697217 291 }
bonnyngangu 0:61128d697217 292
bonnyngangu 0:61128d697217 293 void BallMove()
bonnyngangu 0:61128d697217 294 {
bonnyngangu 0:61128d697217 295 if ( g_timer_flag ) { // ticker interrupt
bonnyngangu 0:61128d697217 296 g_timer_flag = 0; // clear flag
bonnyngangu 0:61128d697217 297 update_physics_engine();
bonnyngangu 0:61128d697217 298 check_collisions();
bonnyngangu 0:61128d697217 299 redraw_screen();
bonnyngangu 0:61128d697217 300 }
bonnyngangu 0:61128d697217 301 }
bonnyngangu 0:61128d697217 302
bonnyngangu 0:61128d697217 303 void redraw_screen()
bonnyngangu 0:61128d697217 304 {
bonnyngangu 0:61128d697217 305 lcd.clear();
bonnyngangu 0:61128d697217 306 lcd.drawCircle(pos.x,pos.y,BALLRADIUS,1); // x,y,radius,black fill
bonnyngangu 0:61128d697217 307 lcd.refresh(); // update display
bonnyngangu 0:61128d697217 308 }
bonnyngangu 0:61128d697217 309
bonnyngangu 0:61128d697217 310 void check_collisions()
bonnyngangu 0:61128d697217 311 {
bonnyngangu 0:61128d697217 312 // see if ball has hit the floor (subtract the radius since the position is the centre of the ball)
bonnyngangu 0:61128d697217 313 if ( pos.y >= 47 - BALLRADIUS ) {
bonnyngangu 0:61128d697217 314 pos.y = 47 - BALLRADIUS; // need to force this or else ball can end up going 'underground'
bonnyngangu 0:61128d697217 315 vel.y = -1.0 * vel.y; // y velocity is reflected and dampened
bonnyngangu 0:61128d697217 316 // y accleration is still gravity
bonnyngangu 0:61128d697217 317 }
bonnyngangu 0:61128d697217 318
bonnyngangu 0:61128d697217 319 else if ( pos.y >= 45 - BALLRADIUS) {
bonnyngangu 0:61128d697217 320 pos.y = 45 - BALLRADIUS; // need to force this or else ball can end up going 'underground'
bonnyngangu 0:61128d697217 321 vel.y = -4.0 * vel.y; // y velocity is reflected and dampened
bonnyngangu 0:61128d697217 322 // y accleration is still gravity
bonnyngangu 0:61128d697217 323 }
bonnyngangu 0:61128d697217 324
bonnyngangu 0:61128d697217 325 // has ball gone off the right-hand side?
bonnyngangu 0:61128d697217 326 if ( pos.x >= 83 - BALLRADIUS ) {
bonnyngangu 0:61128d697217 327 pos.x = 83 - BALLRADIUS; // need to force this or else ball can end up going off screen
bonnyngangu 0:61128d697217 328 vel.x = -1.5 * vel.x; // reflect and damp velocity
bonnyngangu 0:61128d697217 329 acc.x = -acc.x; // reflect accleration
bonnyngangu 0:61128d697217 330 }
bonnyngangu 0:61128d697217 331
bonnyngangu 0:61128d697217 332 // what about the left?
bonnyngangu 0:61128d697217 333 if ( pos.x <= BALLRADIUS ) {
bonnyngangu 0:61128d697217 334 pos.x = BALLRADIUS; // need to force this or else ball can end up going off screen
bonnyngangu 0:61128d697217 335 vel.x = -0.5 * vel.x; // reflect and damp velocity
bonnyngangu 0:61128d697217 336 acc.x = -acc.x; // reflect accleration
bonnyngangu 0:61128d697217 337 }
bonnyngangu 0:61128d697217 338
bonnyngangu 0:61128d697217 339 }
bonnyngangu 0:61128d697217 340
bonnyngangu 0:61128d697217 341 void update_physics_engine()
bonnyngangu 0:61128d697217 342 {
bonnyngangu 0:61128d697217 343 // from Newton's Laws
bonnyngangu 0:61128d697217 344
bonnyngangu 0:61128d697217 345 acc.x = 0.9F*acc.x; // reduce a little due to air friction
bonnyngangu 0:61128d697217 346
bonnyngangu 0:61128d697217 347 // calc new velocity (assume 'unit' time)
bonnyngangu 0:61128d697217 348 vel.x = vel.x + acc.x; // * g_gt;
bonnyngangu 0:61128d697217 349 vel.y = vel.y + acc.y; // * g_gt;
bonnyngangu 0:61128d697217 350
bonnyngangu 0:61128d697217 351 // calc new position (assume 'unit' time)
bonnyngangu 0:61128d697217 352 pos.x = pos.x + vel.x;// * g_gt;
bonnyngangu 0:61128d697217 353 pos.y = pos.y + vel.y;// * g_dt;
bonnyngangu 0:61128d697217 354
bonnyngangu 0:61128d697217 355 // should really multiply the above by the time-step,
bonnyngangu 0:61128d697217 356 // but since the pixel can only be a integer value,
bonnyngangu 0:61128d697217 357 // it makes the motion a little 'jumpy'.
bonnyngangu 0:61128d697217 358
bonnyngangu 0:61128d697217 359 }
bonnyngangu 0:61128d697217 360
bonnyngangu 0:61128d697217 361 void init_ball()
bonnyngangu 0:61128d697217 362 {
bonnyngangu 0:61128d697217 363 // initial position (top-left)
bonnyngangu 0:61128d697217 364 pos.x = BALLRADIUS;
bonnyngangu 0:61128d697217 365 pos.y = BALLRADIUS;
bonnyngangu 0:61128d697217 366 // initial velocity - still
bonnyngangu 0:61128d697217 367 vel.x = 0.0;
bonnyngangu 0:61128d697217 368 vel.y = 0.0;
bonnyngangu 0:61128d697217 369 // initial acceleration - gravity and a bit of push to right
bonnyngangu 0:61128d697217 370 acc.x = 0.5;
bonnyngangu 0:61128d697217 371 acc.y = 1.0; // +ve so ball accelerates to bottom of display (top of screen is y=0, bottom is y=47)
bonnyngangu 0:61128d697217 372 // should be 9.8, but can play with value to get a 'nice' ball movement
bonnyngangu 0:61128d697217 373 }
bonnyngangu 0:61128d697217 374
bonnyngangu 0:61128d697217 375 void game_timer_isr()
bonnyngangu 0:61128d697217 376 {
bonnyngangu 0:61128d697217 377 g_timer_flag = 1;
bonnyngangu 0:61128d697217 378 }