rpi4-osdev/part6-breakout/kernel.c
2021-02-09 16:40:33 +00:00

236 lines
6.3 KiB
C

#include "fb.h"
#include "io.h"
// The screen
#define WIDTH 1920
#define HEIGHT 1080
#define MARGIN 30
#define VIRTWIDTH (WIDTH-(2*MARGIN))
#define FONT_BPG 8
// For the bricks
#define ROWS 5
#define COLS 10
unsigned int bricks = ROWS * COLS;
// Gameplay
#define NUM_LIVES 3
// OBJECT TRACKING
struct Object
{
unsigned int type;
unsigned int x;
unsigned int y;
unsigned int width;
unsigned int height;
unsigned char alive;
};
enum {
OBJ_NONE = 0,
OBJ_BRICK = 1,
OBJ_PADDLE = 2,
OBJ_BALL = 3
};
#define OBJS_ADDRESS 0x02100000 // Somewhere safe to store a lot of data
unsigned int numobjs = 0;
struct Object *objects = (struct Object *)OBJS_ADDRESS;
struct Object *ball;
struct Object *paddle;
void removeObject(struct Object *object)
{
drawRect(object->x, object->y, object->x + object->width, object->y + object->height, 0, 1);
object->alive = 0;
}
void moveObject(struct Object *object, int xoff, int yoff)
{
moveRect(object->x, object->y, object->width, object->height, xoff, yoff, 0x00);
object->x = object->x + xoff;
object->y = object->y + yoff;
}
struct Object *detectCollision(struct Object *with, int xoff, int yoff)
{
for (int i=0; i<numobjs;i++) {
if (&objects[i] != with && objects[i].alive == 1) {
if (with->x + xoff > objects[i].x + objects[i].width || objects[i].x > with->x + xoff + with->width) {
// with is too far left or right to ocllide
} else if (with->y + yoff > objects[i].y + objects[i].height || objects[i].y > with->y + yoff + with->height) {
// with is too far up or down to ocllide
} else {
// Collision!
return &objects[i];
}
}
}
return 0;
}
// KEY HANDLER
unsigned char getUart()
{
unsigned char ch = 0;
if (uart_isReadByteReady()) ch = uart_readByte();
return ch;
}
// OBJECT INITIALISERS
void initBricks()
{
int brickwidth = 32;
int brickheight = 8;
int brickspacer = 20;
static int brickcols[] = { 0x11, 0x22, 0xEE, 0x44, 0x66 };
int ybrick = MARGIN + brickheight;
for (int i=0; i<ROWS; i++) {
int xbrick = MARGIN + (VIRTWIDTH/COLS/2) - (brickwidth/2);
for (int j = 0; j<COLS; j++) {
drawRect(xbrick, ybrick, xbrick+brickwidth, ybrick+brickheight, brickcols[i], 1);
objects[numobjs].type = OBJ_BRICK;
objects[numobjs].x = xbrick;
objects[numobjs].y = ybrick;
objects[numobjs].width = brickwidth;
objects[numobjs].height = brickheight;
objects[numobjs].alive = 1;
numobjs++;
xbrick += (VIRTWIDTH/COLS);
}
ybrick = ybrick + brickspacer;
}
}
void initBall()
{
int ballradius = 15;
drawCircle(WIDTH/2, HEIGHT/2, ballradius, 0x55, 1);
objects[numobjs].type = OBJ_BALL;
objects[numobjs].x = (WIDTH/2) - ballradius;
objects[numobjs].y = (HEIGHT/2) - ballradius;
objects[numobjs].width = ballradius * 2;
objects[numobjs].height = ballradius * 2;
objects[numobjs].alive = 1;
ball = &objects[numobjs];
numobjs++;
}
void initPaddle()
{
int paddlewidth = 80;
int paddleheight = 20;
drawRect((WIDTH-paddlewidth)/2, (HEIGHT-MARGIN-paddleheight), (WIDTH-paddlewidth)/2 + paddlewidth, (HEIGHT-MARGIN), 0x11, 1);
objects[numobjs].type = OBJ_PADDLE;
objects[numobjs].x = (WIDTH-paddlewidth)/2;
objects[numobjs].y = (HEIGHT-MARGIN-paddleheight);
objects[numobjs].width = paddlewidth;
objects[numobjs].height = paddleheight;
objects[numobjs].alive = 1;
paddle = &objects[numobjs];
numobjs++;
}
void drawScoreboard(int score, int lives)
{
char tens = score / 10; score -= (10 * tens);
char ones = score;
drawString((WIDTH/2)-252, MARGIN-25, "Score: 0 Lives: ", 0x0f, 3);
drawChar(tens + 0x30, (WIDTH/2)-252 + (8*8*3), MARGIN-25, 0x0f, 3);
drawChar(ones + 0x30, (WIDTH/2)-252 + (8*9*3), MARGIN-25, 0x0f, 3);
drawChar((char)lives + 0x30, (WIDTH/2)-252 + (8*20*3), MARGIN-25, 0x0f, 3);
}
void main()
{
struct Object *foundObject;
unsigned char ch = 0;
int lives = NUM_LIVES;
int points = 0;
int velocity_x = 1;
int velocity_y = 3;
uart_init();
fb_init();
initBricks();
initBall();
initPaddle();
drawScoreboard(points, lives);
while (!getUart()); // Wait for keypress to start game
while (lives > 0 && bricks > 0) {
// Get any waiting input and flush the buffer
if ( ( ch = getUart() ) ) {
if (ch == 'l') if (paddle->x + paddle->width + (paddle->width / 2) <= WIDTH-MARGIN) moveObject(paddle, paddle->width / 2, 0);
if (ch == 'h') if (paddle->x >= MARGIN+(paddle->width / 2)) moveObject(paddle, -(paddle->width / 2), 0);
}
uart_loadOutputFifo();
// Are we going to hit anything?
foundObject = detectCollision(ball, velocity_x, velocity_y);
if (foundObject) {
if (foundObject == paddle) {
velocity_y = -velocity_y;
// Are we going to hit the side of the paddle
if (ball->x + ball->width + velocity_x == paddle->x || ball->x + velocity_x == paddle->x + paddle->width) velocity_x = -velocity_x;
} else if (foundObject->type == OBJ_BRICK) {
removeObject(foundObject);
velocity_y = -velocity_y;
bricks--;
points++;
drawScoreboard(points, lives);
}
}
wait_msec(4000); // Wait a little...
moveObject(ball, velocity_x, velocity_y);
// Check we're in the game arena still
if (ball->x + ball->width >= WIDTH-MARGIN) {
velocity_x = -velocity_x;
} else if (ball->x <= MARGIN) {
velocity_x = -velocity_x;
} else if (ball->y + ball->height >= HEIGHT-MARGIN) {
lives--;
removeObject(ball);
removeObject(paddle);
initBall();
initPaddle();
drawScoreboard(points, lives);
} else if (ball->y <= MARGIN) {
velocity_y = -velocity_y;
}
}
int zoom = WIDTH/192;
int strwidth = 10 * FONT_BPG * zoom;
int strheight = FONT_BPG * zoom;
if (bricks == 0) drawString((WIDTH/2)-(strwidth/2), (HEIGHT/2)-(strheight/2), "Well done!", 0x02, zoom);
else drawString((WIDTH/2)-(strwidth/2), (HEIGHT/2)-(strheight/2), "Game over!", 0x04, zoom);
while (1);
}