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Be more overt about masking.

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This commit is contained in:
Thomas Harte 2023-03-19 23:00:41 -04:00
parent 235d54bb67
commit 2bf2abf4b2
1 changed files with 22 additions and 10 deletions
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32
Components/9918/Implementation/9918Base.hpp
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@ -284,20 +284,20 @@ template <Personality personality> struct Base: public Storage<personality> {
default:
case ScreenMode::YamahaGraphics4: // 256 pixels @ 4bpp
return AddressT(
(location.v[0] >> 1) +
((location.v[0] >> 1) & 127) +
(location.v[1] << 7)
);
case ScreenMode::YamahaGraphics5: // 512 pixels @ 2bpp
return AddressT(
(location.v[0] >> 2) +
((location.v[0] >> 2) & 127) +
(location.v[1] << 7)
);
case ScreenMode::YamahaGraphics6: { // 512 pixels @ 4bpp
const auto linear_address =
AddressT(
(location.v[0] >> 1) +
((location.v[0] >> 1) & 255) +
(location.v[1] << 8)
);
return expansion ? linear_address : rotate(linear_address);
@ -306,7 +306,7 @@ template <Personality personality> struct Base: public Storage<personality> {
case ScreenMode::YamahaGraphics7: { // 256 pixels @ 8bpp
const auto linear_address =
AddressT(
(location.v[0] >> 0) +
((location.v[0] >> 0) & 255) +
(location.v[1] << 8)
);
return expansion ? linear_address : rotate(linear_address);
@ -382,28 +382,39 @@ template <Personality personality> struct Base: public Storage<personality> {
auto &context = Storage<personality>::command_context_;
const uint8_t *const source = (context.arguments & 0x10) ? Storage<personality>::expansion_ram_.data() : ram_.data();
const AddressT source_mask = (context.arguments & 0x10) ? 0x1fff : 0xffff;
uint8_t *const destination = (context.arguments & 0x20) ? Storage<personality>::expansion_ram_.data() : ram_.data();
const AddressT destination_mask = (context.arguments & 0x20) ? 0x1fff : 0xffff;
switch(Storage<personality>::next_command_step_) {
// Duplicative, but keeps the compiler happy.
case CommandStep::None:
break;
case CommandStep::CopySourcePixelToStatus:
Storage<personality>::colour_status_ = extract_colour(source[command_address(context.source, context.arguments & 0x10)], context.source);
Storage<personality>::colour_status_ =
extract_colour(
source[command_address(context.source, context.arguments & 0x10) & source_mask],
context.source
);
Storage<personality>::command_->advance();
Storage<personality>::update_command_step(access_column);
break;
case CommandStep::ReadSourcePixel:
context.latched_colour.set(extract_colour(source[command_address(context.source, context.arguments & 0x10)], context.source));
context.latched_colour.set(
extract_colour(
source[command_address(context.source, context.arguments & 0x10)] & source_mask,
context.source)
);
Storage<personality>::minimum_command_column_ = access_column + 32;
Storage<personality>::next_command_step_ = CommandStep::ReadDestinationPixel;
break;
case CommandStep::ReadDestinationPixel:
Storage<personality>::command_latch_ = source[command_address(context.destination, context.arguments & 0x20)];
Storage<personality>::command_latch_ =
source[command_address(context.destination, context.arguments & 0x20) & source_mask];
Storage<personality>::minimum_command_column_ = access_column + 24;
Storage<personality>::next_command_step_ = CommandStep::WritePixel;
@ -411,7 +422,7 @@ template <Personality personality> struct Base: public Storage<personality> {
case CommandStep::WritePixel: {
const auto [mask, unmasked_colour] = command_colour_mask(context.destination);
const auto address = command_address(context.destination, context.arguments & 0x20);
const auto address = command_address(context.destination, context.arguments & 0x20) & destination_mask;
const uint8_t colour = unmasked_colour & mask;
context.latched_colour.reset();
@ -450,14 +461,15 @@ template <Personality personality> struct Base: public Storage<personality> {
if(Storage<personality>::command_->y_only) {
source_vector.v[0] = context.destination.v[0];
}
context.latched_colour.set(source[command_address(source_vector, context.arguments & 0x10)]);
context.latched_colour.set(source[command_address(source_vector, context.arguments & 0x10) & source_mask]);
Storage<personality>::minimum_command_column_ = access_column + 24;
Storage<personality>::next_command_step_ = CommandStep::WriteByte;
} break;
case CommandStep::WriteByte:
destination[command_address(context.destination, context.arguments & 0x20)] = context.latched_colour.has_value() ? context.latched_colour.colour : context.colour.colour;
destination[command_address(context.destination, context.arguments & 0x20) & destination_mask]
= context.latched_colour.has_value() ? context.latched_colour.colour : context.colour.colour;
context.latched_colour.reset();
Storage<personality>::command_->advance();