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Entrusts IIe-esque character logic fully to the ROM.

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This commit is contained in:
Thomas Harte 2018-08-11 18:45:39 -04:00
parent a13eb351da
commit 60ab6f0c2a
1 changed files with 19 additions and 22 deletions
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41
Machines/AppleII/Video.hpp
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@ -262,18 +262,20 @@ template <class BusHandler, bool is_iie> class Video: public VideoBase {
case GraphicsMode::Text: {
const uint8_t inverses[] = {
0xff,
alternative_character_set_ ? static_cast<uint8_t>(0xff) : static_cast<uint8_t>((flash_ / flash_length) * 0xff),
static_cast<uint8_t>((flash_ / flash_length) * 0xff),
0x00,
0x00
};
const uint8_t masks[] = {
alternative_character_set_ ? static_cast<uint8_t>(0x7f) : static_cast<uint8_t>(0x3f),
is_iie ? 0x7f : 0x3f,
};
for(int c = column_; c < pixel_end; ++c) {
const uint8_t character = bus_handler_.perform_read(static_cast<uint16_t>(text_address + c));
const uint8_t xor_mask = inverses[character >> 6];
const std::size_t character_address = static_cast<std::size_t>(((character & masks[character >> 7]) << 3) + pixel_row);
int character = bus_handler_.perform_read(static_cast<uint16_t>(text_address + c));
if(is_iie) {
character |= alternative_character_set_ ? 0x100 : 0;
} else {
character &= 0x3f;
}
const uint8_t xor_mask = is_iie ? 0xff : inverses[character >> 6];
const std::size_t character_address = static_cast<std::size_t>((character << 3) + pixel_row);
const uint8_t character_pattern = character_rom_[character_address] ^ xor_mask;
// The character ROM is output MSB to LSB rather than LSB to MSB.
@ -290,26 +292,21 @@ template <class BusHandler, bool is_iie> class Video: public VideoBase {
} break;
case GraphicsMode::DoubleText: {
const uint8_t inverses[] = {
0xff,
alternative_character_set_ ? static_cast<uint8_t>(0xff) : static_cast<uint8_t>((flash_ / flash_length) * 0xff),
0x00,
0x00
};
const uint8_t masks[] = {
alternative_character_set_ ? static_cast<uint8_t>(0x7f) : static_cast<uint8_t>(0x3f),
is_iie ? 0x7f : 0x3f,
};
for(int c = column_; c < pixel_end; ++c) {
const uint16_t characters = bus_handler_.perform_aux_read(static_cast<uint16_t>(text_address + c));
const std::size_t character_addresses[2] = {
static_cast<std::size_t>((((characters >> 8) & masks[characters >> 15]) << 3) + pixel_row),
static_cast<std::size_t>(((characters & masks[(characters >> 7)&1]) << 3) + pixel_row),
static_cast<std::size_t>(
(((characters >> 8)) << 3) + pixel_row
),
static_cast<std::size_t>(
(characters << 3) + pixel_row
),
};
const size_t pattern_offset = alternative_character_set_ ? (256*8) : 0;
const uint8_t character_patterns[2] = {
static_cast<uint8_t>(character_rom_[character_addresses[0]] ^ inverses[(characters >> 14) & 3]),
static_cast<uint8_t>(character_rom_[character_addresses[1]] ^ inverses[(characters >> 6) & 3]),
character_rom_[character_addresses[0] + pattern_offset],
character_rom_[character_addresses[1] + pattern_offset],
};
// The character ROM is output MSB to LSB rather than LSB to MSB.