mirror of
https://github.com/lefticus/6502-cpp.git
synced 2024-12-21 10:30:35 +00:00
617e11244e
This change does not affect the generated code, other than the assembler labels for the data. The data will still be initialized at compilation time.
433 lines
12 KiB
C++
433 lines
12 KiB
C++
#include <cstdint>
|
|
#include <array>
|
|
#include <utility>
|
|
#include <algorithm>
|
|
#include <tuple>
|
|
|
|
|
|
namespace {
|
|
volatile uint8_t &memory(const uint16_t loc)
|
|
{
|
|
return *reinterpret_cast<uint8_t *>(loc);
|
|
}
|
|
|
|
template<typename T>
|
|
auto square(T t) {
|
|
return t * t;
|
|
}
|
|
|
|
constexpr bool test_bit(const uint8_t data, const uint8_t bit)
|
|
{
|
|
return (data & (1 << bit)) != 0;
|
|
};
|
|
|
|
struct Color
|
|
{
|
|
uint8_t num;
|
|
uint8_t r;
|
|
uint8_t g;
|
|
uint8_t b;
|
|
};
|
|
|
|
struct JoyStick
|
|
{
|
|
static constexpr uint16_t JOYSTICK_PORT_A = 56320; // joystick #2
|
|
static constexpr uint16_t JOYSTICK_PORT_B = 56321; // joystick #1
|
|
|
|
struct PortData
|
|
{
|
|
uint8_t data;
|
|
};
|
|
|
|
JoyStick(const PortData d)
|
|
: up(!test_bit(d.data, 0)),
|
|
down(!test_bit(d.data, 1)),
|
|
left(!test_bit(d.data, 2)),
|
|
right(!test_bit(d.data, 3)),
|
|
fire(!test_bit(d.data, 4))
|
|
{
|
|
}
|
|
|
|
JoyStick(const uint8_t port_num)
|
|
: JoyStick(PortData{port_num==2?memory(JOYSTICK_PORT_A):memory(JOYSTICK_PORT_B)})
|
|
{
|
|
}
|
|
|
|
auto direction_vector() const
|
|
{
|
|
return std::make_pair(left?-1:(right?1:0), up?-1:(down?1:0));
|
|
}
|
|
|
|
bool up,down,left,right,fire;
|
|
};
|
|
|
|
///
|
|
/// New Code
|
|
///
|
|
template<typename L1, typename L2, typename R1, typename R2>
|
|
auto operator+=(std::pair<L1&, L2&> lhs, const std::pair<R1, R2> &rhs)
|
|
{
|
|
lhs.first += rhs.first;
|
|
lhs.second += rhs.second;
|
|
return lhs;
|
|
}
|
|
|
|
template<typename L1, typename L2, typename R1, typename R2>
|
|
decltype(auto) operator*=(std::pair<L1, L2> &lhs, const std::pair<R1, R2> &rhs)
|
|
{
|
|
lhs.first *= rhs.first;
|
|
lhs.second *= rhs.second;
|
|
return (lhs);
|
|
}
|
|
|
|
void set_bit(const uint16_t loc, const uint8_t bitnum, bool val)
|
|
{
|
|
if (val) {
|
|
memory(loc) |= (1 << bitnum);
|
|
} else {
|
|
memory(loc) &= (0xFF ^ (1 << bitnum));
|
|
}
|
|
}
|
|
|
|
struct Player
|
|
{
|
|
Player(const uint8_t num, std::pair<volatile uint8_t &, volatile uint8_t &> sprite_pos,
|
|
const std::pair<uint8_t, uint8_t> &start_pos)
|
|
: player_num(num),
|
|
pos(sprite_pos)
|
|
{
|
|
pos = start_pos;
|
|
}
|
|
|
|
void update_position()
|
|
{
|
|
pos.second += JoyStick(player_num).direction_vector().second * 3;
|
|
};
|
|
|
|
void scored() {
|
|
++score;
|
|
}
|
|
|
|
const uint8_t player_num;
|
|
std::pair<volatile uint8_t &, volatile uint8_t &> pos;
|
|
uint8_t score = '0';
|
|
};
|
|
///
|
|
/// End New Code
|
|
///
|
|
|
|
|
|
|
|
|
|
struct VIC_II
|
|
{
|
|
static constexpr uint8_t SPRITE_ALIGNMENT = 64;
|
|
static constexpr uint16_t SPRITE_DATA_POINTERS = 2040;
|
|
static constexpr uint16_t VIDEO_REGISTERS = 53248;
|
|
static constexpr uint16_t VIDEO_MEMORY = 1024;
|
|
static constexpr uint16_t BORDER_COLOR = 53280;
|
|
static constexpr uint16_t BACKGROUND_COLOR = 53281;
|
|
static constexpr uint16_t SPRITE_POSITION_REGISTERS = VIDEO_REGISTERS;
|
|
static constexpr uint16_t SPRITE_ENABLE_BITS = VIDEO_REGISTERS + 21;
|
|
static constexpr uint16_t SPRITE_EXPAND_VERTICAL = VIDEO_REGISTERS + 23;
|
|
static constexpr uint16_t SPRITE_PRIORITY = VIDEO_REGISTERS + 27;
|
|
static constexpr uint16_t SPRITE_MULTICOLOR = VIDEO_REGISTERS + 28;
|
|
static constexpr uint16_t SPRITE_EXPAND_HORIZONTAL = VIDEO_REGISTERS + 29;
|
|
static constexpr uint16_t SPRITE_COLLISIONS = VIDEO_REGISTERS + 30;
|
|
static constexpr uint16_t SPRITE_0_COLOR = VIDEO_REGISTERS + 39;
|
|
static constexpr uint16_t SPRITE_1_COLOR = SPRITE_0_COLOR + 1;
|
|
static constexpr uint16_t SPRITE_2_COLOR = SPRITE_1_COLOR + 1;
|
|
static constexpr uint16_t SCREEN_RASTER_LINE = 53266;
|
|
|
|
|
|
volatile uint8_t& border() {
|
|
return memory(BORDER_COLOR);
|
|
}
|
|
|
|
volatile uint8_t& background() {
|
|
return memory(BACKGROUND_COLOR);
|
|
}
|
|
|
|
volatile uint8_t& display(uint8_t x, uint8_t y)
|
|
{
|
|
return memory(VIDEO_MEMORY + y * 40 + x);
|
|
}
|
|
|
|
template<uint8_t r, uint8_t g, uint8_t b>
|
|
static auto color_comparison(const Color &lhs, const Color &rhs)
|
|
{
|
|
// distance between colors:
|
|
// sqrt( (r1 - r2)^2 + (g1 - g2)^2 + (b1 - b2)^2 )
|
|
return (square(lhs.r - r) + square(lhs.g - g) + square(lhs.b - b))
|
|
< (square(rhs.r - r) + square(rhs.g - g) + square(rhs.b - b));
|
|
}
|
|
|
|
template<uint8_t r, uint8_t g, uint8_t b, typename Colors>
|
|
static auto nearest_color(const Colors &colors)
|
|
{
|
|
return *std::min_element(std::begin(colors), std::end(colors),
|
|
color_comparison<r,g,b>);
|
|
}
|
|
|
|
auto frame(Player &p1, Player &p2)
|
|
{
|
|
struct Frame
|
|
{
|
|
Frame(VIC_II &t_vic, Player &p1, Player &p2)
|
|
: player1(p1), player2(p2), vic(t_vic)
|
|
{
|
|
while (memory(SCREEN_RASTER_LINE) != 250) {}
|
|
}
|
|
|
|
~Frame() {
|
|
vic.display(10, 12) = player1.score;
|
|
vic.display(20, 12) = player2.score;
|
|
}
|
|
|
|
Player &player1;
|
|
Player &player2;
|
|
VIC_II &vic;
|
|
};
|
|
|
|
return Frame(*this, p1, p2);
|
|
}
|
|
|
|
template<bool multicolor>
|
|
struct SpriteLine {
|
|
uint8_t pixels[3];
|
|
|
|
typedef uint_least64_t numeric_t;
|
|
|
|
/// Pixel format converter.
|
|
static constexpr uint8_t c(const numeric_t m)
|
|
{
|
|
if constexpr (multicolor)
|
|
// 0b00ii00jj00kk00ll -> 0biijjkkll
|
|
return uint8_t(m >> 0 & 3 << 0) |
|
|
uint8_t(m >> 2 & 3 << 2) |
|
|
uint8_t(m >> 4 & 3 << 4) |
|
|
uint8_t(m >> 6 & 3 << 6);
|
|
return uint8_t(m);
|
|
}
|
|
|
|
/// Input bits per byte.
|
|
constexpr static auto ibb = multicolor ? 16 : 8;
|
|
|
|
/// Constructor.
|
|
constexpr SpriteLine(const numeric_t line)
|
|
: pixels{c(line >> (2 * ibb)), c(line >> ibb), c(line)}
|
|
{}
|
|
};
|
|
|
|
template<bool multicolor>
|
|
struct Sprite {
|
|
typedef SpriteLine<multicolor> Line;
|
|
alignas(SPRITE_ALIGNMENT) Line lines[SPRITE_ALIGNMENT / sizeof(Line)];
|
|
};
|
|
|
|
typedef Sprite<false> HighResSprite;
|
|
typedef Sprite<true> MultiColorSprite;
|
|
|
|
///
|
|
/// New Code
|
|
///
|
|
template<bool multicolor>
|
|
void enable_sprite(const uint8_t sprite_number,
|
|
const Sprite<multicolor>& bitmap,
|
|
const bool low_priority,
|
|
const bool double_width, const bool double_height)
|
|
{
|
|
#if 0 // error: static_assert expression is not an integral constant
|
|
static_assert((std::ptrdiff_t(bitmap.memory) & 0x7000) != 0x1000,
|
|
"The addresses 0x1000 to 0x1fff and 0x9000 to 0x9fff"
|
|
"point to the character generator ROM, not RAM.");
|
|
static_assert(std::ptrdiff_t(bitmap.memory) < 0x4000,
|
|
"The data must be within the first (default)"
|
|
" 16KiB VIC-II bank.");
|
|
#endif
|
|
memory(SPRITE_DATA_POINTERS + sprite_number)
|
|
= (std::ptrdiff_t(bitmap.lines) & 0x3fff) / SPRITE_ALIGNMENT;
|
|
set_bit(SPRITE_ENABLE_BITS, sprite_number, true);
|
|
set_bit(SPRITE_EXPAND_HORIZONTAL, sprite_number, double_width);
|
|
set_bit(SPRITE_EXPAND_VERTICAL, sprite_number, double_height);
|
|
set_bit(SPRITE_MULTICOLOR, sprite_number, multicolor);
|
|
set_bit(SPRITE_PRIORITY, sprite_number, low_priority);
|
|
}
|
|
|
|
auto sprite_collisions() {
|
|
const auto collisions = memory(SPRITE_COLLISIONS);
|
|
|
|
return std::make_tuple(
|
|
test_bit(collisions, 0),test_bit(collisions, 1),test_bit(collisions, 2),
|
|
test_bit(collisions, 3),test_bit(collisions, 4),test_bit(collisions, 5),
|
|
test_bit(collisions, 6),test_bit(collisions, 7));
|
|
}
|
|
|
|
volatile uint8_t &sprite_1_color()
|
|
{
|
|
return memory(SPRITE_1_COLOR);
|
|
}
|
|
|
|
volatile uint8_t &sprite_2_color()
|
|
{
|
|
return memory(SPRITE_2_COLOR);
|
|
}
|
|
|
|
std::pair<volatile uint8_t &, volatile uint8_t &>
|
|
sprite_pos(const uint8_t sprite_num)
|
|
{
|
|
return {
|
|
memory(SPRITE_POSITION_REGISTERS + sprite_num * 2),
|
|
memory(SPRITE_POSITION_REGISTERS + sprite_num * 2 + 1)
|
|
};
|
|
}
|
|
///
|
|
/// End New Code
|
|
///
|
|
|
|
|
|
};
|
|
|
|
}
|
|
|
|
int main()
|
|
{
|
|
const std::array<Color, 16> colors = {{
|
|
Color{0, 0x00, 0x00, 0x00},
|
|
Color{1, 0xFF, 0xFF, 0xFF},
|
|
Color{2, 0x88, 0x39, 0x32},
|
|
Color{3, 0x67, 0xB6, 0xBD},
|
|
Color{4, 0x8B, 0x3F, 0x96},
|
|
Color{5, 0x55, 0xA0, 0x49},
|
|
Color{6, 0x40, 0x31, 0x8D},
|
|
Color{7, 0xBF, 0xCE, 0x72},
|
|
Color{8, 0x8B, 0x54, 0x29},
|
|
Color{9, 0x57, 0x42, 0x00},
|
|
Color{10, 0xB8, 0x69, 0x62},
|
|
Color{11, 0x50, 0x50, 0x50},
|
|
Color{12, 0x78, 0x78, 0x78},
|
|
Color{13, 0x94, 0xE0, 0x89},
|
|
Color{14, 0x78, 0x69, 0xC4},
|
|
Color{15, 0x9F, 0x9F, 0x9F}
|
|
}};
|
|
|
|
VIC_II vic;
|
|
|
|
/// The ball image.
|
|
static const VIC_II::HighResSprite sBall
|
|
{{
|
|
0b000000000000000000000000,
|
|
0b000000000000000000000000,
|
|
0b000000000111111000000000,
|
|
0b000000011111111110000000,
|
|
0b000000110111111111000000,
|
|
0b000001100011111111100000,
|
|
0b000001110111111111100000,
|
|
0b000011111111111111110000,
|
|
0b000011111111111111110000,
|
|
0b000011111111111111110000,
|
|
0b000000111111111111000000,
|
|
0b000011000000000000110000,
|
|
0b000011111111111111110000,
|
|
0b000001111111111111100000,
|
|
0b000001111111111111100000,
|
|
0b000000111111111111000000,
|
|
0b000000011111111110000000,
|
|
0b000000000111111000000000,
|
|
0b000000000000000000000000,
|
|
0b000000000000000000000000,
|
|
0b000000000000000000000000
|
|
}};
|
|
|
|
/// The bat image.
|
|
static const VIC_II::MultiColorSprite sBat = {{
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000002200000,
|
|
0x000003300000,
|
|
0x000001100000,
|
|
0x000003300000,
|
|
0x000001100000,
|
|
0x000003300000
|
|
}};
|
|
|
|
vic.enable_sprite(0, sBall, true, false, false);
|
|
vic.enable_sprite(1, sBat, false, false, true);
|
|
vic.enable_sprite(2, sBat, false, false, true);
|
|
vic.border() = vic.nearest_color<128,128,128>(colors).num; // 50% grey
|
|
vic.background() = vic.nearest_color<0,0,0>(colors).num; // black
|
|
vic.sprite_1_color() = vic.nearest_color<255,0,0>(colors).num; // red
|
|
vic.sprite_2_color() = vic.nearest_color<0,255,0>(colors).num; // green
|
|
|
|
|
|
///
|
|
/// Game Logic
|
|
///
|
|
std::pair<int8_t, int8_t> ball_velocity{1,1};
|
|
|
|
const auto reset_ball = [&vic]{
|
|
// resets position but keeps velocity
|
|
vic.sprite_pos(0) = std::make_pair(255/2, 255/2);
|
|
};
|
|
|
|
reset_ball();
|
|
|
|
Player p1(1, vic.sprite_pos(1), {15, 255/2});
|
|
Player p2(2, vic.sprite_pos(2), {255, 255/2});
|
|
|
|
///
|
|
/// Game Loop
|
|
///
|
|
while (true) {
|
|
auto frame = vic.frame(p1, p2);
|
|
|
|
if (const auto [s0, s1, s2, s3, s4, s5, s6, s7] = vic.sprite_collisions();
|
|
s0 && (s1 || s2))
|
|
{
|
|
// ball hit paddle, invert ball x velocity
|
|
ball_velocity *= std::make_pair(-1, 1);
|
|
// "bounce" ball out of collision area
|
|
vic.sprite_pos(0) += std::make_pair(ball_velocity.first, 0);
|
|
}
|
|
|
|
|
|
// Update paddle positions
|
|
p1.update_position();
|
|
p2.update_position();
|
|
|
|
|
|
const auto score = [reset_ball](auto &player){
|
|
// called when a player scores
|
|
player.scored();
|
|
reset_ball();
|
|
};
|
|
|
|
if (const auto [ball_x, ball_y] = vic.sprite_pos(0) += ball_velocity;
|
|
ball_y == 45 || ball_y == 235)
|
|
{
|
|
// ball hit the top or bottom wall, invert ball y velocity
|
|
ball_velocity *= std::make_pair(1, -1);
|
|
} else if (ball_x == 1) {
|
|
// ball hit left wall, player 2 scored
|
|
score(p2);
|
|
} else if (ball_x == 255) {
|
|
// ball hit right wall, player 1 scored
|
|
score(p1);
|
|
}
|
|
}
|
|
}
|
|
|