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mirror of https://github.com/TomHarte/CLK.git synced 2026-01-26 21:16:19 +00:00
Files
CLK/Components/SAA5050/SAA5050.cpp

164 lines
7.5 KiB
C++

//
// SAA5050.cpp
// Clock Signal
//
// Created by Thomas Harte on 24/09/2025.
// Copyright © 2025 Thomas Harte. All rights reserved.
//
#include "SAA5050.hpp"
#include <cstdint>
namespace {
// SAA5050 font, padded out to one byte per row. The least-significant five bits of each byte
// are the meaningful pixels for that row, with the LSB being on the right.
constexpr uint8_t font[][10] = {
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, }, // Character 32.
{0x00, 0x04, 0x04, 0x04, 0x04, 0x04, 0x00, 0x04, 0x00, 0x00, },
{0x00, 0x0a, 0x0a, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, },
{0x00, 0x06, 0x09, 0x08, 0x1c, 0x08, 0x08, 0x1f, 0x00, 0x00, },
{0x00, 0x0e, 0x15, 0x14, 0x0e, 0x05, 0x15, 0x0e, 0x00, 0x00, },
{0x00, 0x18, 0x19, 0x02, 0x04, 0x08, 0x13, 0x03, 0x00, 0x00, },
{0x00, 0x08, 0x14, 0x14, 0x08, 0x15, 0x12, 0x0d, 0x00, 0x00, },
{0x00, 0x04, 0x04, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, },
{0x00, 0x02, 0x04, 0x08, 0x08, 0x08, 0x04, 0x02, 0x00, 0x00, },
{0x00, 0x08, 0x04, 0x02, 0x02, 0x02, 0x04, 0x08, 0x00, 0x00, },
{0x00, 0x04, 0x15, 0x0e, 0x04, 0x0e, 0x15, 0x04, 0x00, 0x00, },
{0x00, 0x00, 0x04, 0x04, 0x1f, 0x04, 0x04, 0x00, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x04, 0x08, 0x00, },
{0x00, 0x00, 0x00, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, },
{0x00, 0x00, 0x01, 0x02, 0x04, 0x08, 0x10, 0x00, 0x00, 0x00, },
{0x00, 0x04, 0x0a, 0x11, 0x11, 0x11, 0x0a, 0x04, 0x00, 0x00, },
{0x00, 0x04, 0x0c, 0x04, 0x04, 0x04, 0x04, 0x0e, 0x00, 0x00, },
{0x00, 0x0e, 0x11, 0x01, 0x06, 0x08, 0x10, 0x1f, 0x00, 0x00, },
{0x00, 0x1f, 0x01, 0x02, 0x06, 0x01, 0x11, 0x0e, 0x00, 0x00, },
{0x00, 0x02, 0x06, 0x0a, 0x12, 0x1f, 0x02, 0x02, 0x00, 0x00, },
{0x00, 0x1f, 0x10, 0x1e, 0x01, 0x01, 0x11, 0x0e, 0x00, 0x00, },
{0x00, 0x06, 0x08, 0x10, 0x1e, 0x11, 0x11, 0x0e, 0x00, 0x00, },
{0x00, 0x1f, 0x01, 0x02, 0x04, 0x08, 0x08, 0x08, 0x00, 0x00, },
{0x00, 0x0e, 0x11, 0x11, 0x0e, 0x11, 0x11, 0x0e, 0x00, 0x00, },
{0x00, 0x0e, 0x11, 0x11, 0x0f, 0x01, 0x02, 0x0c, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x04, 0x04, 0x08, 0x00, },
{0x00, 0x02, 0x04, 0x08, 0x10, 0x08, 0x04, 0x02, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x1f, 0x00, 0x1f, 0x00, 0x00, 0x00, 0x00, },
{0x00, 0x08, 0x04, 0x02, 0x01, 0x02, 0x04, 0x08, 0x00, 0x00, },
{0x00, 0x0e, 0x11, 0x02, 0x04, 0x04, 0x00, 0x04, 0x00, 0x00, },
{0x00, 0x0e, 0x11, 0x17, 0x15, 0x17, 0x10, 0x0e, 0x00, 0x00, },
{0x00, 0x04, 0x0a, 0x11, 0x11, 0x1f, 0x11, 0x11, 0x00, 0x00, },
{0x00, 0x1e, 0x11, 0x11, 0x1e, 0x11, 0x11, 0x1e, 0x00, 0x00, },
{0x00, 0x0e, 0x11, 0x10, 0x10, 0x10, 0x11, 0x0e, 0x00, 0x00, },
{0x00, 0x1e, 0x11, 0x11, 0x11, 0x11, 0x11, 0x1e, 0x00, 0x00, },
{0x00, 0x1f, 0x10, 0x10, 0x1e, 0x10, 0x10, 0x1f, 0x00, 0x00, },
{0x00, 0x1f, 0x10, 0x10, 0x1e, 0x10, 0x10, 0x10, 0x00, 0x00, },
{0x00, 0x0e, 0x11, 0x10, 0x10, 0x13, 0x11, 0x0f, 0x00, 0x00, },
{0x00, 0x11, 0x11, 0x11, 0x1f, 0x11, 0x11, 0x11, 0x00, 0x00, },
{0x00, 0x0e, 0x04, 0x04, 0x04, 0x04, 0x04, 0x0e, 0x00, 0x00, },
{0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x11, 0x0e, 0x00, 0x00, },
{0x00, 0x11, 0x12, 0x14, 0x18, 0x14, 0x12, 0x11, 0x00, 0x00, },
{0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x1f, 0x00, 0x00, },
{0x00, 0x11, 0x1b, 0x15, 0x15, 0x11, 0x11, 0x11, 0x00, 0x00, },
{0x00, 0x11, 0x11, 0x19, 0x15, 0x13, 0x11, 0x11, 0x00, 0x00, },
{0x00, 0x0e, 0x11, 0x11, 0x11, 0x11, 0x11, 0x0e, 0x00, 0x00, },
{0x00, 0x1e, 0x11, 0x11, 0x1e, 0x10, 0x10, 0x10, 0x00, 0x00, },
{0x00, 0x0e, 0x11, 0x11, 0x11, 0x15, 0x12, 0x0d, 0x00, 0x00, },
{0x00, 0x1e, 0x11, 0x11, 0x1e, 0x14, 0x12, 0x11, 0x00, 0x00, },
{0x00, 0x0e, 0x11, 0x10, 0x0e, 0x01, 0x11, 0x0e, 0x00, 0x00, },
{0x00, 0x1f, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x00, 0x00, },
{0x00, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x0e, 0x00, 0x00, },
{0x00, 0x11, 0x11, 0x11, 0x0a, 0x0a, 0x04, 0x04, 0x00, 0x00, },
{0x00, 0x11, 0x11, 0x11, 0x15, 0x15, 0x15, 0x0a, 0x00, 0x00, },
{0x00, 0x11, 0x11, 0x0a, 0x04, 0x0a, 0x11, 0x11, 0x00, 0x00, },
{0x00, 0x11, 0x11, 0x0a, 0x04, 0x04, 0x04, 0x04, 0x00, 0x00, },
{0x00, 0x1f, 0x01, 0x02, 0x04, 0x08, 0x10, 0x1f, 0x00, 0x00, },
{0x00, 0x00, 0x04, 0x08, 0x1f, 0x08, 0x04, 0x00, 0x00, 0x00, },
{0x00, 0x10, 0x10, 0x10, 0x10, 0x16, 0x01, 0x02, 0x04, 0x07, },
{0x00, 0x00, 0x04, 0x02, 0x1f, 0x02, 0x04, 0x00, 0x00, 0x00, },
{0x00, 0x00, 0x04, 0x0e, 0x15, 0x04, 0x04, 0x00, 0x00, 0x00, },
{0x00, 0x0a, 0x0a, 0x1f, 0x0a, 0x1f, 0x0a, 0x0a, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x00, 0x1f, 0x00, 0x00, 0x00, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x0e, 0x01, 0x0f, 0x11, 0x0f, 0x00, 0x00, },
{0x00, 0x10, 0x10, 0x1e, 0x11, 0x11, 0x11, 0x1e, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x0f, 0x10, 0x10, 0x10, 0x0f, 0x00, 0x00, },
{0x00, 0x01, 0x01, 0x0f, 0x11, 0x11, 0x11, 0x0f, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x0e, 0x11, 0x1f, 0x10, 0x0e, 0x00, 0x00, },
{0x00, 0x02, 0x04, 0x04, 0x0e, 0x04, 0x04, 0x04, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x0f, 0x11, 0x11, 0x11, 0x0f, 0x01, 0x0e, },
{0x00, 0x10, 0x10, 0x1e, 0x11, 0x11, 0x11, 0x11, 0x00, 0x00, },
{0x00, 0x04, 0x00, 0x0c, 0x04, 0x04, 0x04, 0x0e, 0x00, 0x00, },
{0x00, 0x04, 0x00, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x08, },
{0x00, 0x08, 0x08, 0x09, 0x0a, 0x0c, 0x0a, 0x09, 0x00, 0x00, },
{0x00, 0x0c, 0x04, 0x04, 0x04, 0x04, 0x04, 0x0e, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x1a, 0x15, 0x15, 0x15, 0x15, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x1e, 0x11, 0x11, 0x11, 0x11, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x0e, 0x11, 0x11, 0x11, 0x0e, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x1e, 0x11, 0x11, 0x11, 0x1e, 0x10, 0x10, },
{0x00, 0x00, 0x00, 0x0f, 0x11, 0x11, 0x11, 0x0f, 0x01, 0x01, },
{0x00, 0x00, 0x00, 0x0b, 0x0c, 0x08, 0x08, 0x08, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x0f, 0x10, 0x0e, 0x01, 0x1e, 0x00, 0x00, },
{0x00, 0x04, 0x04, 0x0e, 0x04, 0x04, 0x04, 0x02, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x11, 0x11, 0x11, 0x11, 0x0f, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x11, 0x11, 0x0a, 0x0a, 0x04, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x11, 0x11, 0x15, 0x15, 0x0a, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x11, 0x0a, 0x04, 0x0a, 0x11, 0x00, 0x00, },
{0x00, 0x00, 0x00, 0x11, 0x11, 0x11, 0x11, 0x0f, 0x01, 0x0e, },
{0x00, 0x00, 0x00, 0x1f, 0x02, 0x04, 0x08, 0x1f, 0x00, 0x00, },
{0x00, 0x10, 0x10, 0x10, 0x10, 0x11, 0x03, 0x05, 0x07, 0x01, },
{0x00, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x00, 0x00, },
{0x00, 0x18, 0x04, 0x18, 0x04, 0x19, 0x03, 0x05, 0x07, 0x01, },
{0x00, 0x00, 0x04, 0x00, 0x1f, 0x00, 0x04, 0x00, 0x00, 0x00, },
{0x00, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x00, 0x00, },
};
}
using namespace Mullard;
void SAA5050Serialiser::begin_frame() {
line_ = -1;
row_ = 0;
}
void SAA5050Serialiser::begin_line() {
++line_;
if(line_ == 20) {
line_ = 0;
++row_;
}
output_.alpha = 0x7;
output_.background = 0x0;
has_output_ = false;
}
bool SAA5050Serialiser::has_output() const {
return has_output_;
}
SAA5050Serialiser::Output SAA5050Serialiser::output() {
has_output_ = false;
return output_;
}
void SAA5050Serialiser::add(const uint8_t c) {
has_output_ = true;
const uint8_t masked_c = c & 0x7f;
if(masked_c < 32) {
// TODO: all control characters!
output_.pixels = 0;
return;
}
// TODO: proper scaling!
const uint8_t source = font[c - 32][line_ >> 1];
output_.pixels = uint16_t(
((source & 0x01) ? 0xb0000'0000'0011 : 0) |
((source & 0x02) ? 0xb0000'0000'1100 : 0) |
((source & 0x04) ? 0xb0000'0011'0000 : 0) |
((source & 0x08) ? 0xb0000'1100'0000 : 0) |
((source & 0x10) ? 0xb0011'0000'0000 : 0) |
((source & 0x20) ? 0xb1100'0000'0000 : 0)
);
}