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Merge pull request #569 from TomHarte/224px

Adds 'full' support for 224- and 240-line SMS modes
This commit is contained in:
Thomas Harte 2018-10-23 21:22:19 -04:00 committed by GitHub
commit cba8e6814f
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 39 additions and 18 deletions

View File

@ -138,7 +138,7 @@ void Base::posit_sprite(LineBuffer &buffer, int sprite_number, int sprite_positi
return;
// A sprite Y of 208 means "don't scan the list any further".
if(mode_timing_.allow_sprite_terminator && sprite_position == 208) {
if(mode_timing_.allow_sprite_terminator && sprite_position == mode_timing_.sprite_terminator) {
buffer.sprites_stopped = true;
return;
}
@ -191,11 +191,27 @@ void TMS9918::run_for(const HalfCycles cycles) {
// ---------------------------------------
// Latch scrolling position, if necessary.
// ---------------------------------------
if(write_pointer_.column < 61 && end_column >= 61) {
if(!write_pointer_.row) {
master_system_.latched_vertical_scroll = master_system_.vertical_scroll;
if(is_sega_vdp(personality_)) {
if(write_pointer_.column < 61 && end_column >= 61) {
if(!write_pointer_.row) {
master_system_.latched_vertical_scroll = master_system_.vertical_scroll;
if(master_system_.mode4_enable) {
mode_timing_.pixel_lines = 192;
if(mode2_enable_ && mode1_enable_) mode_timing_.pixel_lines = 224;
if(mode2_enable_ && mode3_enable_) mode_timing_.pixel_lines = 240;
mode_timing_.sprite_terminator = 0xd0;
if(mode_timing_.pixel_lines != 192) {
mode_timing_.sprite_terminator = 0xf0;
}
mode_timing_.first_vsync_line = (mode_timing_.total_lines + mode_timing_.pixel_lines) >> 1;
mode_timing_.end_of_frame_interrupt_position.row = mode_timing_.pixel_lines + 1;
}
}
line_buffer.latched_horizontal_scroll = master_system_.horizontal_scroll;
}
line_buffer.latched_horizontal_scroll = master_system_.horizontal_scroll;
}

View File

@ -155,9 +155,10 @@ class Base {
} end_of_frame_interrupt_position;
int line_interrupt_position = -1;
// Enables or disabled the recognition of 0xd0 as a sprite
// list terminator.
// Enables or disabled the recognition of the sprite
// list terminator, and sets the terminator value.
bool allow_sprite_terminator = true;
uint8_t sprite_terminator = 0xd0;
} mode_timing_;
uint8_t line_interrupt_target = 0xff;
@ -279,9 +280,6 @@ class Base {
if(is_sega_vdp(personality_) && master_system_.mode4_enable) {
screen_mode_ = ScreenMode::SMSMode4;
mode_timing_.pixel_lines = 192;
if(mode2_enable_ && mode1_enable_) mode_timing_.pixel_lines = 224;
if(mode2_enable_ && mode3_enable_) mode_timing_.pixel_lines = 240;
mode_timing_.maximum_visible_sprites = 8;
return;
}
@ -646,12 +644,12 @@ class Base {
#define sprite_fetch(sprite) {\
line_buffer.active_sprites[sprite].x = \
ram_[\
sprite_attribute_table_address_ & size_t(0x3f80 | (line_buffer.active_sprites[sprite].index << 1))\
sprite_attribute_table_address & size_t(0x3f80 | (line_buffer.active_sprites[sprite].index << 1))\
] - (master_system_.shift_sprites_8px_left ? 8 : 0); \
const uint8_t name = ram_[\
sprite_attribute_table_address_ & size_t(0x3f81 | (line_buffer.active_sprites[sprite].index << 1))\
sprite_attribute_table_address & size_t(0x3f81 | (line_buffer.active_sprites[sprite].index << 1))\
] & (sprites_16x16_ ? ~1 : ~0);\
const size_t graphic_location = sprite_generator_table_address_ & size_t(0x2000 | (name << 5) | (line_buffer.active_sprites[sprite].row << 2)); \
const size_t graphic_location = sprite_generator_table_address & size_t(0x2000 | (name << 5) | (line_buffer.active_sprites[sprite].row << 2)); \
line_buffer.active_sprites[sprite].image[0] = ram_[graphic_location]; \
line_buffer.active_sprites[sprite].image[1] = ram_[graphic_location+1]; \
line_buffer.active_sprites[sprite].image[2] = ram_[graphic_location+2]; \
@ -670,8 +668,8 @@ class Base {
#define sprite_y_read(location, sprite) \
slot(location): \
posit_sprite(sprite_selection_buffer, sprite, ram_[sprite_attribute_table_address_ & ((sprite) | 0x3f00)], write_pointer_.row); \
posit_sprite(sprite_selection_buffer, sprite+1, ram_[sprite_attribute_table_address_ & ((sprite + 1) | 0x3f00)], write_pointer_.row); \
posit_sprite(sprite_selection_buffer, sprite, ram_[sprite_attribute_table_address & ((sprite) | 0x3f00)], write_pointer_.row); \
posit_sprite(sprite_selection_buffer, sprite+1, ram_[sprite_attribute_table_address & ((sprite + 1) | 0x3f00)], write_pointer_.row); \
#define fetch_tile_name(column, row_info) {\
const size_t scrolled_column = (column - horizontal_offset) & 0x1f;\
@ -717,20 +715,27 @@ class Base {
LineBuffer &sprite_selection_buffer = line_buffers_[(write_pointer_.row + 1) % mode_timing_.total_lines];
const int horizontal_offset = (write_pointer_.row >= 16 || !master_system_.horizontal_scroll_lock) ? (line_buffer.latched_horizontal_scroll >> 3) : 0;
// Limit address bits in use if this is a SMS2 mode.
const bool is_tall_mode = mode_timing_.pixel_lines != 192;
const size_t pattern_name_address = pattern_name_address_ | (is_tall_mode ? 0xc00 : 0);
const size_t pattern_name_offset = is_tall_mode ? 0x100 : 0;
const size_t sprite_attribute_table_address = sprite_attribute_table_address_ | (is_tall_mode ? 0x80 : 0);
const size_t sprite_generator_table_address = sprite_generator_table_address_ | (is_tall_mode ? 0x1800 : 0);
// Determine row info for the screen both (i) if vertical scrolling is applied; and (ii) if it isn't.
// The programmer can opt out of applying vertical scrolling to the right-hand portion of the display.
const int scrolled_row = (write_pointer_.row + master_system_.latched_vertical_scroll) % 224;
const int scrolled_row = (write_pointer_.row + master_system_.latched_vertical_scroll) % (is_tall_mode ? 256 : 224);
struct RowInfo {
size_t pattern_address_base;
size_t sub_row[2];
};
const RowInfo scrolled_row_info = {
pattern_name_address_ & static_cast<size_t>(((scrolled_row & ~7) << 3) | 0x3800),
pattern_name_address & size_t(((scrolled_row & ~7) << 3) | 0x3800) - pattern_name_offset,
{static_cast<size_t>((scrolled_row & 7) << 2), 28 ^ static_cast<size_t>((scrolled_row & 7) << 2)}
};
RowInfo row_info;
if(master_system_.vertical_scroll_lock) {
row_info.pattern_address_base = pattern_name_address_ & static_cast<size_t>(((write_pointer_.row & ~7) << 3) | 0x3800);
row_info.pattern_address_base = pattern_name_address & size_t(((write_pointer_.row & ~7) << 3) | 0x3800) - pattern_name_offset;
row_info.sub_row[0] = size_t((write_pointer_.row & 7) << 2);
row_info.sub_row[1] = 28 ^ size_t((write_pointer_.row & 7) << 2);
} else row_info = scrolled_row_info;