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6502-cpp/examples/test_mod.cpp
2021-05-13 23:35:57 -06:00

236 lines
5.1 KiB
C++

#include <array>
#include <chrono>
#include <cstdint>
#include <cstring>
#include <string_view>
enum Colors : uint8_t { WHITE = 0x01 };
static volatile uint8_t &memory_loc(const uint16_t loc) {
return *reinterpret_cast<volatile uint8_t *>(loc);
}
static void poke(const uint16_t loc, const uint8_t value) {
memory_loc(loc) = value;
}
static std::uint8_t peek(const std::uint16_t loc) { return memory_loc(loc); }
static void decrement_border_color() { --memory_loc(0xd020); }
static void increment_border_color() { ++memory_loc(0xd020); }
static bool joystick_down() {
uint8_t joystick_state = peek(0xDC00);
return (joystick_state & 2) == 0;
}
unsigned int __attribute__ ((noinline)) multiply(unsigned int x, unsigned int y) {
unsigned int result = 0;
unsigned int input = x;
unsigned int add_in = y;
while (input != 0) {
if (input & 1) {
result += add_in;
}
add_in <<= 1;
input >>= 1;
}
return result;
}
void use_data(std::array<char, 1024> &data);
static void puts(uint8_t x, uint8_t y, std::string_view str) {
const auto start = 0x400 + (y * 40 + x);
std::memcpy(const_cast<uint8_t *>(&memory_loc(start)), str.data(),
str.size());
}
template<std::uint8_t Width, std::uint8_t Height>
struct Graphic
{
std::array<std::uint8_t, Width * Height> data;
static constexpr auto width() noexcept {
return Width;
}
static constexpr auto height() noexcept {
return Height;
}
constexpr Graphic() = default;
constexpr Graphic(std::array<uint8_t, Width * Height> data_) noexcept : data(data_) {}
constexpr Graphic(std::initializer_list<uint8_t> data_) noexcept {
std::copy(begin(data_), end(data_), begin(data));
}
constexpr auto &operator()(const std::uint8_t x, const std::uint8_t y) noexcept {
return data[y * Width + x];
}
constexpr const auto &operator()(const std::uint8_t x, const std::uint8_t y) const noexcept {
return data[y * Width + x];
}
};
static void putc(uint8_t x, uint8_t y, uint8_t c) {
const auto start = 0x400 + (y * 40 + x);
poke(start, c);
}
static void put_hex(uint8_t x, uint8_t y, uint8_t value) {
const auto put_nibble = [](auto x, auto y, uint8_t nibble) {
if (nibble <= 9) {
putc(x, y, nibble + 48);
} else {
putc(x, y, nibble - 9);
}
};
put_nibble(x + 1, y, 0xF & value);
put_nibble(x, y, 0xF & (value >> 4));
}
static void put_hex(uint8_t x, uint8_t y, uint16_t value) {
put_hex(x+2,y, static_cast<std::uint8_t>(0xFF & value));
put_hex(x,y, static_cast<std::uint8_t>(0xFF & (value >> 8)));
}
static void put_graphic(uint8_t x, uint8_t y, const auto &graphic)
{
for (uint8_t cur_y = 0; cur_y < graphic.height(); ++cur_y) {
for (uint8_t cur_x = 0; cur_x < graphic.width(); ++cur_x) {
putc(cur_x + x, cur_y + y, graphic(cur_x, cur_y));
}
}
}
struct Clock {
using milliseconds = std::chrono::duration<std::uint16_t, std::milli>;
// return elapsed time since last restart
[[nodiscard]] milliseconds restart() {
// stop Timer A
poke(0xDC0E, 0b00000000);
// last value
const auto previous_value = static_cast<std::uint16_t>(
peek(0xDC04) | (static_cast<uint16_t>(peek(0xDC05)) << 8));
// reset timer
poke(0xDC04, 0xFF);
poke(0xDC05, 0xFF);
// restart timer A
poke(0xDC0E, 0b00010001);
return milliseconds{0xFFFF - previous_value};
}
Clock() { [[maybe_unused]] const auto value = restart(); }
};
int main() {
// static constexpr std::array<std::uint8_t, 1000> data{0};
// std::memcpy(const_cast<uint8_t*>(&memory_loc(0x400)), data.data(),
// data.size());
static constexpr auto pic =
Graphic<5,4>{
78,119,77,32,32,
101,32,32,80,32,
101,79,101,103,32,
76,101,76,122,88
};
static constexpr auto map1 =
Graphic<4, 2>{
1,0,1,0,
1,1,1,1
};
static constexpr auto map2 =
Graphic<6, 3>{
1,0,1,0,0,0,
1,1,1,1,0,1,
0,0,0,1,0,0
};
/*
static constexpr auto map =
Graphic<10, 2>{
0,1,0,1,0,0,0,1,0,0,
1,0,0,0,0,0,1,0,0,0,
};
*/
// put_graphic(10,10,pic);
const auto draw_map = [](const auto &map) {
for (std::uint8_t y=0; y < map.height(); ++y) {
for (std::uint8_t x = 0; x < map.width(); ++x) {
if (map(x, y) == 1) {
put_graphic(x*4, y*4, pic);
}
}
}
};
// draw_map(map1);
Clock game_clock{};
std::uint16_t counter = 0;
std::uint8_t y = 19;
while (true) {
const auto us_elapsed = game_clock.restart().count();
draw_map(map2);
puts(5, 17, "timing history");
puts(21, 17, "16bit counter");
put_hex(5, y, us_elapsed);
put_hex(21, y, counter);
put_hex(26, y, static_cast<std::uint16_t>(multiply(counter, y)));
// put_hex(31, y, counter*10);
if (y++ == 24) {
y = 19;
}
++counter;
increment_border_color();
}
/*
const auto background_color = [](Colors col) {
memory_loc(0xd021) = static_cast<uint8_t>(col);
};
background_color(Colors::WHITE);
while(true) {
if (joystick_down()) {
increment_border_color();
} else {
decrement_border_color();
}
}
*/
}