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Takes a shot at an all-border output.

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This commit is contained in:
Thomas Harte 2021-03-18 22:29:24 -04:00
parent 87fc7c02e8
commit fe3e8f87e7
2 changed files with 62 additions and 2 deletions
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62
Machines/Sinclair/ZXSpectrum/Video.hpp
View File

@ -12,6 +12,8 @@
#include "../../../Outputs/CRT/CRT.hpp"
#include "../../../ClockReceiver/ClockReceiver.hpp"
#include <algorithm>
namespace Sinclair {
namespace ZXSpectrum {
@ -76,15 +78,57 @@ template <VideoTiming timing> class Video {
public:
void run_for(HalfCycles duration) {
constexpr auto timings = get_timings();
constexpr int first_line = timings.first_delay / timings.cycles_per_line;
constexpr int sync_position = 200 * 2;
constexpr int sync_length = 14 * 2;
// Advance time. TODO: all the drawing.
time_since_interrupt_ = (time_since_interrupt_ + duration.as<int>()) % (timings.cycles_per_line * timings.lines_per_frame);
int cycles_remaining = duration.as<int>();
while(cycles_remaining) {
int line = time_since_interrupt_ / timings.cycles_per_line;
int offset = time_since_interrupt_ % timings.cycles_per_line;
const int cycles_this_line = std::min(cycles_remaining, timings.cycles_per_line - offset);
const int end_offset = offset + cycles_this_line;
if(line < 3) {
// Output sync line.
crt_.output_sync(cycles_this_line);
} else /* if((line < first_line) || (line >= first_line+192)) */ {
// Output plain border line.
if(offset < sync_position) {
const int border_duration = std::min(sync_position, end_offset) - offset;
output_border(border_duration);
offset += border_duration;
}
if(offset >= sync_position && offset < sync_position+sync_length && end_offset > offset) {
const int sync_duration = std::min(sync_position + sync_length, end_offset) - offset;
crt_.output_sync(sync_duration);
offset += sync_duration;
}
if(offset >= sync_position + sync_length && end_offset > offset) {
const int border_duration = end_offset - offset;
output_border(border_duration);
}
} /* else {
// TODO: output pixel line.
} */
cycles_remaining -= cycles_this_line;
time_since_interrupt_ = (time_since_interrupt_ + cycles_this_line) % (timings.cycles_per_line * timings.lines_per_frame);
}
}
private:
// TODO: how long is the interrupt line held for?
static constexpr int interrupt_duration = 48;
void output_border(int duration) {
uint8_t *const colour_pointer = crt_.begin_data(1);
if(colour_pointer) *colour_pointer = border_colour_;
crt_.output_level(duration);
}
public:
Video() :
crt_(227 * 2, 1, Outputs::Display::Type::PAL50, Outputs::Display::InputDataType::Red2Green2Blue2)
@ -126,6 +170,10 @@ template <VideoTiming timing> class Video {
return timings.delays[line_position & 7];
}
void set_border_colour(uint8_t colour) {
border_colour_ = palette[colour];
}
/// Sets the scan target.
void set_scan_target(Outputs::Display::ScanTarget *scan_target) {
crt_.set_scan_target(scan_target);
@ -140,6 +188,16 @@ template <VideoTiming timing> class Video {
int time_since_interrupt_ = 0;
Outputs::CRT::CRT crt_;
const uint8_t *memory_ = nullptr;
uint8_t border_colour_ = 0;
#define RGB(r, g, b) (r << 4) | (g << 2) | b
static constexpr uint8_t palette[] = {
RGB(0, 0, 0), RGB(0, 0, 2), RGB(2, 0, 0), RGB(2, 0, 2),
RGB(0, 2, 0), RGB(0, 2, 2), RGB(2, 2, 0), RGB(2, 2, 2),
RGB(0, 0, 0), RGB(0, 0, 3), RGB(3, 0, 0), RGB(3, 0, 3),
RGB(0, 3, 0), RGB(0, 3, 3), RGB(3, 3, 0), RGB(3, 3, 3),
};
#undef RGB
};
}

2
Machines/Sinclair/ZXSpectrum/ZXSpectrum.cpp
View File

@ -130,6 +130,8 @@ template<Model model> class ConcreteMachine:
update_audio();
audio_toggle_.set_output(*cycle.value & 0x10);
video_->set_border_colour(*cycle.value & 7);
// b0–b2: border colour
// b3: enable tape input (?)
// b4: tape and speaker output