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CLK/Machines/AppleII/Video.cpp

291 lines
9.6 KiB
C++

//
// Video.cpp
// Clock Signal
//
// Created by Thomas Harte on 14/04/2018.
// Copyright 2018 Thomas Harte. All rights reserved.
//
#include "Video.hpp"
using namespace AppleII::Video;
VideoBase::VideoBase(bool is_iie) :
crt_(new Outputs::CRT::CRT(910, 1, Outputs::CRT::DisplayType::NTSC60, 1)),
is_iie_(is_iie) {
// Set a composite sampling function that assumes one byte per pixel input, and
// accepts any non-zero value as being fully on, zero being fully off.
crt_->set_composite_sampling_function(
"float composite_sample(usampler2D sampler, vec2 coordinate, vec2 icoordinate, float phase, float amplitude)"
"{"
"return clamp(texture(sampler, coordinate).r, 0.0, 0.7);"
"}");
// Show only the centre 75% of the TV frame.
crt_->set_video_signal(Outputs::CRT::VideoSignal::Composite);
crt_->set_visible_area(Outputs::CRT::Rect(0.115f, 0.122f, 0.77f, 0.77f));
crt_->set_immediate_default_phase(0.0f);
}
Outputs::CRT::CRT *VideoBase::get_crt() {
return crt_.get();
}
/*
Rote setters and getters.
*/
void VideoBase::set_alternative_character_set(bool alternative_character_set) {
alternative_character_set_ = alternative_character_set;
}
bool VideoBase::get_alternative_character_set() {
return alternative_character_set_;
}
void VideoBase::set_80_columns(bool columns_80) {
columns_80_ = columns_80;
}
bool VideoBase::get_80_columns() {
return columns_80_;
}
void VideoBase::set_80_store(bool store_80) {
store_80_ = store_80;
}
bool VideoBase::get_80_store() {
return store_80_;
}
void VideoBase::set_page2(bool page2) {
page2_ = page2;
}
bool VideoBase::get_page2() {
return page2_;
}
void VideoBase::set_text(bool text) {
text_ = text;
}
bool VideoBase::get_text() {
return text_;
}
void VideoBase::set_mixed(bool mixed) {
mixed_ = mixed;
}
bool VideoBase::get_mixed() {
return mixed_;
}
void VideoBase::set_high_resolution(bool high_resolution) {
high_resolution_ = high_resolution;
}
bool VideoBase::get_high_resolution() {
return high_resolution_;
}
void VideoBase::set_double_high_resolution(bool double_high_resolution) {
double_high_resolution_ = double_high_resolution;
}
bool VideoBase::get_double_high_resolution() {
return double_high_resolution_;
}
void VideoBase::set_character_rom(const std::vector<uint8_t> &character_rom) {
character_rom_ = character_rom;
// Flip all character contents based on the second line of the $ graphic.
if(character_rom_[0x121] == 0x3c || character_rom_[0x122] == 0x3c) {
for(auto &graphic : character_rom_) {
graphic =
((graphic & 0x01) ? 0x40 : 0x00) |
((graphic & 0x02) ? 0x20 : 0x00) |
((graphic & 0x04) ? 0x10 : 0x00) |
((graphic & 0x08) ? 0x08 : 0x00) |
((graphic & 0x10) ? 0x04 : 0x00) |
((graphic & 0x20) ? 0x02 : 0x00) |
((graphic & 0x40) ? 0x01 : 0x00);
}
}
}
uint8_t *VideoBase::output_text(uint8_t *target, uint8_t *source, size_t length, size_t pixel_row) const {
const uint8_t inverses[] = {
0xff,
is_iie_ ? static_cast<uint8_t>(0xff) : static_cast<uint8_t>((flash_ / flash_length) * 0xff),
is_iie_ ? static_cast<uint8_t>(0xff) : static_cast<uint8_t>(0x00),
is_iie_ ? static_cast<uint8_t>(0xff) : static_cast<uint8_t>(0x00)
};
const int or_mask = alternative_character_set_ ? 0x100 : 0x000;
const int and_mask = is_iie_ ? ~0 : 0x3f;
for(size_t c = 0; c < length; ++c) {
const int character = (source[c] | or_mask) & and_mask;
const uint8_t xor_mask = 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.
target[0] = character_pattern & 0x40;
target[1] = character_pattern & 0x20;
target[2] = character_pattern & 0x10;
target[3] = character_pattern & 0x08;
target[4] = character_pattern & 0x04;
target[5] = character_pattern & 0x02;
target[6] = character_pattern & 0x01;
graphics_carry_ = character_pattern & 0x01;
target += 7;
}
return target;
}
uint8_t *VideoBase::output_double_text(uint8_t *target, uint8_t *source, uint8_t *auxiliary_source, size_t length, size_t pixel_row) const {
for(size_t c = 0; c < length; ++c) {
const std::size_t character_addresses[2] = {
static_cast<std::size_t>(
auxiliary_source[c] << 3
) + pixel_row,
static_cast<std::size_t>(
source[c] << 3
) + pixel_row,
};
const size_t pattern_offset = alternative_character_set_ ? (256*8) : 0;
const uint8_t character_patterns[2] = {
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.
target[0] = character_patterns[0] & 0x40;
target[1] = character_patterns[0] & 0x20;
target[2] = character_patterns[0] & 0x10;
target[3] = character_patterns[0] & 0x08;
target[4] = character_patterns[0] & 0x04;
target[5] = character_patterns[0] & 0x02;
target[6] = character_patterns[0] & 0x01;
target[7] = character_patterns[1] & 0x40;
target[8] = character_patterns[1] & 0x20;
target[9] = character_patterns[1] & 0x10;
target[10] = character_patterns[1] & 0x08;
target[11] = character_patterns[1] & 0x04;
target[12] = character_patterns[1] & 0x02;
target[13] = character_patterns[1] & 0x01;
graphics_carry_ = character_patterns[1] & 0x01;
target += 14;
}
return target;
}
uint8_t *VideoBase::output_low_resolution(uint8_t *target, uint8_t *source, size_t length, int row) const {
const int row_shift = row&4;
for(size_t c = 0; c < length; ++c) {
// Low-resolution graphics mode shifts the colour code on a loop, but has to account for whether this
// 14-sample output window is starting at the beginning of a colour cycle or halfway through.
if(c&1) {
target[0] = target[4] = target[8] = target[12] = (source[c] >> row_shift) & 4;
target[1] = target[5] = target[9] = target[13] = (source[c] >> row_shift) & 8;
target[2] = target[6] = target[10] = (source[c] >> row_shift) & 1;
target[3] = target[7] = target[11] = (source[c] >> row_shift) & 2;
graphics_carry_ = (source[c] >> row_shift) & 8;
} else {
target[0] = target[4] = target[8] = target[12] = (source[c] >> row_shift) & 1;
target[1] = target[5] = target[9] = target[13] = (source[c] >> row_shift) & 2;
target[2] = target[6] = target[10] = (source[c] >> row_shift) & 4;
target[3] = target[7] = target[11] = (source[c] >> row_shift) & 8;
graphics_carry_ = (source[c] >> row_shift) & 2;
}
target += 14;
}
return target;
}
uint8_t *VideoBase::output_double_low_resolution(uint8_t *target, uint8_t *source, uint8_t *auxiliary_source, size_t length, int row) const {
const int row_shift = row&4;
for(size_t c = 0; c < length; ++c) {
if(c&1) {
target[0] = target[4] = (auxiliary_source[c] >> row_shift) & 2;
target[1] = target[5] = (auxiliary_source[c] >> row_shift) & 4;
target[2] = target[6] = (auxiliary_source[c] >> row_shift) & 8;
target[3] = (auxiliary_source[c] >> row_shift) & 1;
target[8] = target[12] = (source[c] >> row_shift) & 4;
target[9] = target[13] = (source[c] >> row_shift) & 8;
target[10] = (source[c] >> row_shift) & 1;
target[7] = target[11] = (source[c] >> row_shift) & 2;
graphics_carry_ = (source[c] >> row_shift) & 8;
} else {
target[0] = target[4] = (auxiliary_source[c] >> row_shift) & 8;
target[1] = target[5] = (auxiliary_source[c] >> row_shift) & 1;
target[2] = target[6] = (auxiliary_source[c] >> row_shift) & 2;
target[3] = (auxiliary_source[c] >> row_shift) & 4;
target[8] = target[12] = (source[c] >> row_shift) & 1;
target[9] = target[13] = (source[c] >> row_shift) & 2;
target[10] = (source[c] >> row_shift) & 4;
target[7] = target[11] = (source[c] >> row_shift) & 8;
graphics_carry_ = (source[c] >> row_shift) & 2;
}
target += 14;
}
return target;
}
uint8_t *VideoBase::output_high_resolution(uint8_t *target, uint8_t *source, size_t length) const {
for(size_t c = 0; c < length; ++c) {
// High resolution graphics shift out LSB to MSB, optionally with a delay of half a pixel.
// If there is a delay, the previous output level is held to bridge the gap.
if(base_stream_[c] & 0x80) {
target[0] = graphics_carry_;
target[1] = target[2] = source[c] & 0x01;
target[3] = target[4] = source[c] & 0x02;
target[5] = target[6] = source[c] & 0x04;
target[7] = target[8] = source[c] & 0x08;
target[9] = target[10] = source[c] & 0x10;
target[11] = target[12] = source[c] & 0x20;
target[13] = source[c] & 0x40;
} else {
target[0] = target[1] = source[c] & 0x01;
target[2] = target[3] = source[c] & 0x02;
target[4] = target[5] = source[c] & 0x04;
target[6] = target[7] = source[c] & 0x08;
target[8] = target[9] = source[c] & 0x10;
target[10] = target[11] = source[c] & 0x20;
target[12] = target[13] = source[c] & 0x40;
}
graphics_carry_ = source[c] & 0x40;
target += 14;
}
return target;
}
uint8_t *VideoBase::output_double_high_resolution(uint8_t *target, uint8_t *source, uint8_t *auxiliary_source, size_t length) const {
for(size_t c = 0; c < length; ++c) {
target[0] = graphics_carry_;
target[1] = auxiliary_source[c] & 0x01;
target[2] = auxiliary_source[c] & 0x02;
target[3] = auxiliary_source[c] & 0x04;
target[4] = auxiliary_source[c] & 0x08;
target[5] = auxiliary_source[c] & 0x10;
target[6] = auxiliary_source[c] & 0x20;
target[7] = auxiliary_source[c] & 0x40;
target[8] = auxiliary_source[c] & 0x01;
target[9] = auxiliary_source[c] & 0x02;
target[10] = auxiliary_source[c] & 0x04;
target[11] = auxiliary_source[c] & 0x08;
target[12] = auxiliary_source[c] & 0x10;
target[13] = auxiliary_source[c] & 0x20;
graphics_carry_ = auxiliary_source[c] & 0x40;
target += 14;
}
return target;
}