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Attempts to honour the full CRTC 'sync' period, placing blank and the colour burst.

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This commit is contained in:
Thomas Harte 2018-06-20 22:38:54 -04:00
parent 8b83f58d7a
commit 1f8b69a5b0
1 changed files with 35 additions and 13 deletions
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48
Machines/AmstradCPC/AmstradCPC.cpp
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@ -192,29 +192,44 @@ class CRTCBusHandler {
}
bool is_hsync = (cycles_into_hsync_ >= 2 && cycles_into_hsync_ < 6);
bool is_colour_burst = (cycles_into_hsync_ >= 7 && cycles_into_hsync_ < 11);
// Sync is taken to override pixels, and is combined as a simple OR.
bool is_sync = is_hsync || state.vsync;
bool is_blank = !is_sync && state.hsync;
OutputMode output_mode;
if(is_sync) {
output_mode = OutputMode::Sync;
} else if(is_colour_burst) {
output_mode = OutputMode::ColourBurst;
} else if(is_blank) {
output_mode = OutputMode::Blank;
} else if(state.display_enable) {
output_mode = OutputMode::Pixels;
} else {
output_mode = OutputMode::Border;
}
// If a transition between sync/border/pixels just occurred, flush whatever was
// in progress to the CRT and reset counting.
if(state.display_enable != was_enabled_ || is_sync != was_sync_) {
if(was_sync_) {
crt_->output_sync(cycles_ * 16);
} else {
if(was_enabled_) {
if(cycles_) {
if(output_mode != previous_output_mode_) {
if(cycles_) {
switch(previous_output_mode_) {
default:
case OutputMode::Blank: crt_->output_blank(cycles_ * 16); break;
case OutputMode::Sync: crt_->output_sync(cycles_ * 16); break;
case OutputMode::Border: output_border(cycles_); break;
case OutputMode::ColourBurst: crt_->output_default_colour_burst(cycles_ * 16); break;
case OutputMode::Pixels:
crt_->output_data(cycles_ * 16, cycles_ * 16 / pixel_divider_);
pixel_pointer_ = pixel_data_ = nullptr;
}
} else {
output_border(cycles_);
break;
}
}
cycles_ = 0;
was_sync_ = is_sync;
was_enabled_ = state.display_enable;
previous_output_mode_ = output_mode;
}
// increment cycles since state changed
@ -349,7 +364,7 @@ class CRTCBusHandler {
if(pen_ & 16) {
// If border is[/was] currently being output, flush what should have been
// drawn in the old colour.
if(!was_sync_ && !was_enabled_) {
if(previous_output_mode_ == OutputMode::Border) {
output_border(cycles_);
cycles_ = 0;
}
@ -506,9 +521,16 @@ class CRTCBusHandler {
return mapping[colour];
}
enum class OutputMode {
Sync,
Blank,
ColourBurst,
Border,
Pixels
} previous_output_mode_ = OutputMode::Sync;
unsigned int cycles_ = 0;
bool was_enabled_ = false, was_sync_ = false, was_hsync_ = false, was_vsync_ = false;
bool was_hsync_ = false, was_vsync_ = false;
int cycles_into_hsync_ = 0;
std::unique_ptr<Outputs::CRT::CRT> crt_;