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Attempts to add a proper intermediate buffer for sprites to allow the split of collection and output.

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This commit is contained in:
Thomas Harte 2017-12-08 22:12:39 -05:00
parent 202958303e
commit e1914b4f16
2 changed files with 36 additions and 26 deletions
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45
Components/9918/9918.cpp
View File

@ -80,14 +80,16 @@ void TMS9918::test_sprite(int sprite_number) {
const int sprite_row = (row_ - sprite_position)&255;
if(sprite_row < 0 || sprite_row >= sprite_height_) return;
if(active_sprite_slot_ == 4) {
const int active_sprite_slot = sprite_sets_[active_sprite_set_].active_sprite_slot;
if(active_sprite_slot == 4) {
status_ |= 0x40;
return;
}
active_sprites_[active_sprite_slot_].index = sprite_number;
active_sprites_[active_sprite_slot_].row = sprite_row;
active_sprite_slot_++;
sprite_sets_[active_sprite_set_].active_sprites[active_sprite_slot].index = sprite_number;
sprite_sets_[active_sprite_set_].active_sprites[active_sprite_slot].row = sprite_row;
sprite_sets_[active_sprite_set_].active_sprite_slot++;
}
void TMS9918::get_sprite_contents(int field, int cycles_left, int screen_row) {
@ -103,17 +105,17 @@ void TMS9918::get_sprite_contents(int field, int cycles_left, int screen_row) {
if(field < 4) {
std::memcpy(
&active_sprites_[sprite].info[field],
&ram_[sprite_attribute_table_address_ + (active_sprites_[sprite].index << 2) + field],
&sprite_sets_[active_sprite_set_].active_sprites[sprite].info[field],
&ram_[sprite_attribute_table_address_ + (sprite_sets_[active_sprite_set_].active_sprites[sprite].index << 2) + field],
static_cast<size_t>(std::min(4, final_field) - field));
}
field = std::min(4, final_field);
const int sprite_offset = active_sprites_[sprite].info[2] & ~(sprites_16x16_ ? 3 : 0);
const int sprite_offset = sprite_sets_[active_sprite_set_].active_sprites[sprite].info[2] & ~(sprites_16x16_ ? 3 : 0);
const int sprite_address =
sprite_generator_table_address_ + (sprite_offset << 3) + active_sprites_[sprite].row;
sprite_generator_table_address_ + (sprite_offset << 3) + sprite_sets_[active_sprite_set_].active_sprites[sprite].row;
while(field < final_field) {
active_sprites_[sprite].image[field - 4] = ram_[sprite_address + ((field - 4) << 4)];
sprite_sets_[active_sprite_set_].active_sprites[sprite].image[field - 4] = ram_[sprite_address + ((field - 4) << 4)];
field++;
}
@ -200,6 +202,13 @@ void TMS9918::run_for(const HalfCycles cycles) {
if(access_pointer_ >= 15 && access_pointer_ < 19)
access_pointer_ = std::min(19, access_slot);
// Start new sprite set if this is location 19.
if(access_pointer_ == 19) {
active_sprite_set_ ^= 1;
sprite_sets_[active_sprite_set_].active_sprite_slot = 0;
sprites_stopped_ = false;
}
// Then eight access windows fetch the y position for the first eight sprites.
while(access_pointer_ < 27 && access_pointer_ < access_slot) {
test_sprite(access_pointer_ - 19);
@ -247,7 +256,6 @@ void TMS9918::run_for(const HalfCycles cycles) {
// Sprite slots occur in three quarters of ever fourth window starting from window 28.
const int sprite_start = (access_pointer_ - 28 + 3) >> 2;
const int sprite_end = (end - 28 + 3) >> 2;
// assert(sprite_start >= 0 && sprite_end >= 0 && sprite_start <= 24 && sprite_end <= 24);
for(int column = sprite_start; column < sprite_end; ++column) {
if(column&3) {
test_sprite(7 + column - (column >> 2));
@ -358,24 +366,23 @@ void TMS9918::run_for(const HalfCycles cycles) {
if(output_column_ == first_right_border_column_) {
// Just chuck the sprites on. Quick hack!
for(size_t c = 0; c < 4; ++c) {
const size_t sprite_index = c^3;
if(static_cast<int>(sprite_index) >= active_sprite_slot_) continue;
if(!(active_sprites_[sprite_index].info[3]&15)) continue;
int last_sprite_set = active_sprite_set_ ^ 1;
int c = sprite_sets_[last_sprite_set].active_sprite_slot;
while(c--) {
SpriteSet::ActiveSprite &sprite = sprite_sets_[last_sprite_set].active_sprites[c];
if(!(sprite.info[3]&15)) continue;
for(int p = 0; p < (sprites_16x16_ ? 16 : 8); ++p) {
int x = active_sprites_[sprite_index].info[1] + p;
if(active_sprites_[sprite_index].info[3] & 0x80) x -= 32;
int x = sprite.info[1] + p;
if(sprite.info[3] & 0x80) x -= 32;
if(x >= 0 && x < 256) {
if(((active_sprites_[sprite_index].image[p >> 3] << (p&7)) & 0x80)) pixel_base_[x] = palette[active_sprites_[sprite_index].info[3]&15];
if(((sprite.image[p >> 3] << (p&7)) & 0x80)) pixel_base_[x] = palette[sprite.info[3]&15];
}
}
}
crt_->output_data(static_cast<unsigned int>(first_right_border_column_ - first_pixel_column_), 1);
pixel_target_ = nullptr;
active_sprite_slot_ = 0;
sprites_stopped_ = false;
}
}
}

17
Components/9918/9918.hpp
View File

@ -98,13 +98,16 @@ class TMS9918 {
uint8_t pattern_buffer_[40];
uint8_t colour_buffer_[40];
struct ActiveSprite {
int index = 0;
int row = 0;
uint8_t info[4];
uint8_t image[2];
} active_sprites_[4];
int active_sprite_slot_ = 0;
struct SpriteSet {
struct ActiveSprite {
int index = 0;
int row = 0;
uint8_t info[4];
uint8_t image[2];
} active_sprites[4];
int active_sprite_slot = 0;
} sprite_sets_[2];
int active_sprite_set_ = 0;
bool sprites_stopped_ = false;
int access_pointer_ = 0;