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Corrects various latent errors in optimised TMS video collection.

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This commit is contained in:
Thomas Harte 2017-12-06 20:24:29 -05:00
parent a4f0a260fd
commit 8653eb8b55
2 changed files with 35 additions and 24 deletions
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56
Components/9918/9918.cpp
View File

@ -8,6 +8,7 @@
#include "9918.hpp"
#include <cassert>
#include <cstring>
using namespace TI;
@ -64,10 +65,11 @@ std::shared_ptr<Outputs::CRT::CRT> TMS9918::get_crt() {
}
void TMS9918::test_sprite(int sprite_number) {
if(sprites_stopped_) return;
if(!(status_ & 0x40)) {
status_ = static_cast<uint8_t>((status_ & ~31) | sprite_number);
}
if(sprites_stopped_)
return;
const int sprite_position = ram_[sprite_attribute_table_address_ + (sprite_number << 2)];
// A sprite Y of 208 means "don't scan the list any further".
@ -77,11 +79,7 @@ void TMS9918::test_sprite(int sprite_number) {
}
const int sprite_row = (row_ - sprite_position)&255;
int sprite_height = 8;
if(sprites_16x16_) sprite_height <<= 1;
if(sprites_magnified_) sprite_height <<= 1;
if(sprite_row < 0 || sprite_row >= sprite_height) return;
if(sprite_row < 0 || sprite_row >= sprite_height_) return;
if(active_sprite_slot_ == 4) {
status_ |= 0x40;
return;
@ -92,8 +90,8 @@ void TMS9918::test_sprite(int sprite_number) {
active_sprite_slot_++;
}
void TMS9918::get_sprite_contents(int field, int cycles_left) {
int sprite = 2 + (field / 6);
void TMS9918::get_sprite_contents(int field, int cycles_left, int screen_row) {
int sprite = field / 6;
field %= 6;
while(true) {
@ -101,6 +99,8 @@ void TMS9918::get_sprite_contents(int field, int cycles_left) {
cycles_left -= cycles_in_sprite;
const int final_field = cycles_in_sprite + field;
assert(sprite < 4);
if(field < 4) {
std::memcpy(
&active_sprites_[sprite].info[field],
@ -186,16 +186,19 @@ void TMS9918::run_for(const HalfCycles cycles) {
case LineMode::Character:
// Four access windows: no collection.
access_pointer_ = std::min(5, access_slot);
if(access_pointer_ < 5)
access_pointer_ = std::min(5, access_slot);
// Then ten access windows are filled with collection of sprite 3 and 4 details.
if(access_pointer_ >= 5 && access_pointer_ < 15) {
get_sprite_contents(access_pointer_ - 5 + 14, 15 - access_pointer_);
int end = std::min(15, access_slot);
get_sprite_contents(access_pointer_ - 5 + 14, end - access_pointer_, row_ - 1);
access_pointer_ = std::min(15, access_slot);
}
// Four more access windows: no collection.
access_pointer_ = std::min(19, access_slot);
if(access_pointer_ >= 15 && access_pointer_ < 19)
access_pointer_ = std::min(19, access_slot);
// Then eight access windows fetch the y position for the first eight sprites.
while(access_pointer_ < 27 && access_pointer_ < access_slot) {
@ -241,25 +244,28 @@ void TMS9918::run_for(const HalfCycles cycles) {
pattern_buffer_[column] = ram_[pattern_base + (pattern_names_[column] << 3) + (row_ & 7)];
}
// Sprite slots occur in three quarters of ever fourth window starting from window 32.
const int sprite_start = (access_pointer_ - 32 + 3) >> 2;
const int sprite_end = (end - 32 + 3) >> 2;
// 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) != 3) {
test_sprite(8 + column - (column >> 2));
if(column&3) {
test_sprite(7 + column - (column >> 2));
}
}
access_pointer_ = std::min(154, access_pointer_);
access_pointer_ = std::min(155, access_slot);
}
// Two access windows: no collection.
access_pointer_ = std::min(157, access_slot);
if(access_pointer_ < 157)
access_pointer_ = std::min(157, access_slot);
// Fourteen access windows: collect initial sprite information.
if(access_pointer_ >= 157 && access_pointer_ < 170) {
get_sprite_contents(access_pointer_ - 157, 170 - access_pointer_);
access_pointer_ = std::min(170, access_slot);
if(access_pointer_ >= 157 && access_pointer_ < 171) {
int end = std::min(171, access_slot);
get_sprite_contents(access_pointer_ - 157, end - access_pointer_, row_);
access_pointer_ = std::min(171, access_slot);
}
break;
}
@ -368,6 +374,8 @@ void TMS9918::run_for(const HalfCycles cycles) {
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;
}
}
}
@ -408,8 +416,6 @@ void TMS9918::run_for(const HalfCycles cycles) {
access_pointer_ = column_ = output_column_ = 0;
row_ = (row_ + 1) % frame_lines_;
if(row_ == 192) status_ |= 0x80;
active_sprite_slot_ = 0;
sprites_stopped_ = false;
screen_mode_ = next_screen_mode_;
blank_screen_ = next_blank_screen_;
@ -471,6 +477,10 @@ void TMS9918::set_register(int address, uint8_t value) {
next_screen_mode_ = (next_screen_mode_ & 1) | ((low_write_ & 0x18) >> 3);
sprites_16x16_ = !!(low_write_ & 0x02);
sprites_magnified_ = !!(low_write_ & 0x01);
sprite_height_ = 8;
if(sprites_16x16_) sprite_height_ <<= 1;
if(sprites_magnified_) sprite_height_ <<= 1;
// printf("NSM: %02x\n", next_screen_mode_);
break;

3
Components/9918/9918.hpp
View File

@ -66,6 +66,7 @@ class TMS9918 {
bool sprites_16x16_ = false;
bool sprites_magnified_ = false;
bool generate_interrupts_ = false;
int sprite_height_ = 8;
uint16_t pattern_name_address_ = 0;
uint16_t colour_table_address_ = 0;
uint16_t pattern_generator_table_address_ = 0;
@ -109,7 +110,7 @@ class TMS9918 {
int access_pointer_ = 0;
inline void test_sprite(int sprite_number);
inline void get_sprite_contents(int start, int cycles);
inline void get_sprite_contents(int start, int cycles, int screen_row);
};
};