mirror of
https://github.com/TomHarte/CLK.git
synced 2024-11-30 04:50:08 +00:00
132 lines
3.9 KiB
C++
132 lines
3.9 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;
|
|
|
|
namespace {
|
|
|
|
struct ScaledByteFiller {
|
|
ScaledByteFiller() {
|
|
VideoBase::setup_tables();
|
|
}
|
|
} throwaway;
|
|
|
|
}
|
|
|
|
VideoBase::VideoBase() :
|
|
crt_(new Outputs::CRT::CRT(455, 1, Outputs::CRT::DisplayType::NTSC60, 1)) {
|
|
|
|
// Set a composite sampling function that assumes 1bpp input, and uses just 7 bits per byte.
|
|
crt_->set_composite_sampling_function(
|
|
"float composite_sample(usampler2D sampler, vec2 coordinate, vec2 icoordinate, float phase, float amplitude)"
|
|
"{"
|
|
"uint texValue = texture(sampler, coordinate).r;"
|
|
"texValue >>= int(icoordinate.x) % 7;"
|
|
"return float(texValue & 1u);"
|
|
"}");
|
|
crt_->set_integer_coordinate_multiplier(7.0f);
|
|
|
|
// 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, 0.117f, 0.77f, 0.77f));
|
|
}
|
|
|
|
Outputs::CRT::CRT *VideoBase::get_crt() {
|
|
return crt_.get();
|
|
}
|
|
|
|
uint16_t VideoBase::scaled_byte[256];
|
|
uint16_t VideoBase::low_resolution_patterns[2][16];
|
|
|
|
void VideoBase::setup_tables() {
|
|
for(int c = 0; c < 128; ++c) {
|
|
const uint16_t value =
|
|
((c & 0x01) ? 0x0003 : 0x0000) |
|
|
((c & 0x02) ? 0x000c : 0x0000) |
|
|
((c & 0x04) ? 0x0030 : 0x0000) |
|
|
((c & 0x08) ? 0x0140 : 0x0000) |
|
|
((c & 0x10) ? 0x0600 : 0x0000) |
|
|
((c & 0x20) ? 0x1800 : 0x0000) |
|
|
((c & 0x40) ? 0x6000 : 0x0000);
|
|
|
|
uint8_t *const table_entry = reinterpret_cast<uint8_t *>(&scaled_byte[c]);
|
|
table_entry[0] = static_cast<uint8_t>(value & 0xff);
|
|
table_entry[1] = static_cast<uint8_t>(value >> 8);
|
|
}
|
|
for(int c = 128; c < 256; ++c) {
|
|
uint8_t *const source_table_entry = reinterpret_cast<uint8_t *>(&scaled_byte[c & 0x7f]);
|
|
uint8_t *const destination_table_entry = reinterpret_cast<uint8_t *>(&scaled_byte[c]);
|
|
|
|
destination_table_entry[0] = static_cast<uint8_t>(source_table_entry[0] << 1);
|
|
destination_table_entry[1] = static_cast<uint8_t>((source_table_entry[1] << 1) | (source_table_entry[0] >> 6));
|
|
}
|
|
|
|
for(int c = 0; c < 16; ++c) {
|
|
// Produce the whole 28-bit pattern that would cover two columns.
|
|
const int reversed_c = ((c&0x1) ? 0x8 : 0x0) | ((c&0x2) ? 0x4 : 0x0) | ((c&0x4) ? 0x2 : 0x0) | ((c&0x8) ? 0x1 : 0x0);
|
|
int pattern = 0;
|
|
for(int l = 0; l < 7; ++l) {
|
|
pattern <<= 4;
|
|
pattern |= reversed_c;
|
|
}
|
|
|
|
// Pack that 28-bit pattern into the appropriate look-up tables.
|
|
uint8_t *const left_entry = reinterpret_cast<uint8_t *>(&low_resolution_patterns[0][c]);
|
|
uint8_t *const right_entry = reinterpret_cast<uint8_t *>(&low_resolution_patterns[1][c]);
|
|
left_entry[0] = static_cast<uint8_t>(pattern);;
|
|
left_entry[1] = static_cast<uint8_t>(pattern >> 7);
|
|
right_entry[0] = static_cast<uint8_t>(pattern >> 14);
|
|
right_entry[1] = static_cast<uint8_t>(pattern >> 21);
|
|
}
|
|
}
|
|
|
|
void VideoBase::set_graphics_mode() {
|
|
use_graphics_mode_ = true;
|
|
}
|
|
|
|
void VideoBase::set_text_mode() {
|
|
use_graphics_mode_ = false;
|
|
}
|
|
|
|
void VideoBase::set_mixed_mode(bool mixed_mode) {
|
|
mixed_mode_ = mixed_mode;
|
|
}
|
|
|
|
void VideoBase::set_video_page(int page) {
|
|
video_page_ = page;
|
|
}
|
|
|
|
void VideoBase::set_low_resolution() {
|
|
graphics_mode_ = GraphicsMode::LowRes;
|
|
}
|
|
|
|
void VideoBase::set_high_resolution() {
|
|
graphics_mode_ = GraphicsMode::HighRes;
|
|
}
|
|
|
|
void VideoBase::set_character_rom(const std::vector<uint8_t> &character_rom) {
|
|
character_rom_ = character_rom;
|
|
|
|
// Bytes in the character ROM are stored in reverse bit order. Reverse them
|
|
// ahead of time so as to be able to use the same scaling table as for
|
|
// high-resolution graphics.
|
|
for(auto &byte : character_rom_) {
|
|
byte =
|
|
((byte & 0x40) ? 0x01 : 0x00) |
|
|
((byte & 0x20) ? 0x02 : 0x00) |
|
|
((byte & 0x10) ? 0x04 : 0x00) |
|
|
((byte & 0x08) ? 0x08 : 0x00) |
|
|
((byte & 0x04) ? 0x10 : 0x00) |
|
|
((byte & 0x02) ? 0x20 : 0x00) |
|
|
((byte & 0x01) ? 0x40 : 0x00) |
|
|
(byte & 0x80);
|
|
}
|
|
}
|