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Makes substantial optimisations to text mode.

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Character optimisations to come.
This commit is contained in:
Thomas Harte 2017-12-04 22:18:51 -05:00
parent ec266d6c8e
commit 6eedc99286
2 changed files with 189 additions and 190 deletions
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376
Components/9918/9918.cpp
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@ -103,197 +103,183 @@ void TMS9918::run_for(const HalfCycles cycles) {
const int access_slot = column_ >> 1; // There are only 171 available memory accesses per line. const int access_slot = column_ >> 1; // There are only 171 available memory accesses per line.
switch(line_mode_) { switch(line_mode_) {
case LineMode::Text: case LineMode::Text:
while(access_pointer_ < access_slot) { access_pointer_ = std::min(30, access_slot);
if(access_pointer_ < 29) { if(access_pointer_ >= 30 && access_pointer_ < 150) {
access_pointer_ = std::min(29, access_slot); const int row_base = pattern_name_address_ + (row_ >> 3) * 40;
} const int start_column = (access_pointer_ - 30) / 3;
if(access_pointer_ >= 29) { const int end = std::min(150, access_slot);
int row_base = pattern_name_address_ + (row_ >> 3) * 40;
int character_column = (access_pointer_ - 29) / 3;
const int end = std::min(149, access_slot); // Pattern names are collected every third window starting from window 30.
const int pattern_names_end = (end - 30) / 3;
while(access_pointer_ < end) { for(int column = start_column; column < pattern_names_end; ++column) {
switch(access_pointer_%3) { pattern_names_[column] = ram_[row_base + column];
case 0:
pattern_buffer_[character_column] = ram_[pattern_generator_table_address_ + (pattern_name_ << 3) + (row_ & 7)];
character_column++;
break;
case 1: break; // TODO: CPU access.
case 2:
pattern_name_ = ram_[row_base + character_column];
break;
}
access_pointer_++;
}
} }
if(access_pointer_ >= 149) {
access_pointer_ = access_slot; // Patterns are collected every third window starting from window 32.
const int pattern_buffer_end = (end - 32) / 3;
for(int column = start_column; column < pattern_buffer_end; ++column) {
pattern_buffer_[column] = ram_[pattern_generator_table_address_ + (pattern_names_[column] << 3) + (row_ & 7)];
} }
} }
break; break;
case LineMode::Character: case LineMode::Character:
while(access_pointer_ < access_slot) { // Four access windows: no collection.
// Four access windows: no collection. access_pointer_ = std::min(4, access_slot);
access_pointer_ = std::min(4, access_slot);
// Then ten access windows are filled with collection of sprite 3 and 4 details. // Then ten access windows are filled with collection of sprite 3 and 4 details.
if(access_pointer_ >= 4 && access_pointer_ < 14) { if(access_pointer_ >= 4 && access_pointer_ < 14) {
// TODO: this repeats the code below. // TODO: this repeats the code below.
int end = std::min(14, access_slot); int end = std::min(14, access_slot);
while(access_pointer_ < end) { while(access_pointer_ < end) {
const int offset = access_pointer_ - 2; const int offset = access_pointer_ - 2;
const int target = 2 + (offset / 6); const int target = 2 + (offset / 6);
const int sprite = active_sprites_[target] & 31; const int sprite = active_sprites_[target] & 31;
const int subcycle = offset % 6; const int subcycle = offset % 6;
// printf("%d: %d %d\n", access_pointer_, target, subcycle); switch(subcycle) {
switch(subcycle) { case 0: sprites_[target].y = ram_[sprite_attribute_table_address_ + (sprite << 2)]; break;
case 0: sprites_[target].y = ram_[sprite_attribute_table_address_ + (sprite << 2)]; break; case 1: sprites_[target].x = ram_[sprite_attribute_table_address_ + (sprite << 2) + 1]; break;
case 1: sprites_[target].x = ram_[sprite_attribute_table_address_ + (sprite << 2) + 1]; break; case 2: sprites_[target].pattern_number = ram_[sprite_attribute_table_address_ + (sprite << 2) + 2]; break;
case 2: sprites_[target].pattern_number = ram_[sprite_attribute_table_address_ + (sprite << 2) + 2]; break; case 3: sprites_[target].colour = ram_[sprite_attribute_table_address_ + (sprite << 2) + 3]; break;
case 3: sprites_[target].colour = ram_[sprite_attribute_table_address_ + (sprite << 2) + 3]; break; case 4:
case 4: case 5: {
case 5: { const int sprite_offset = sprites_[target].pattern_number & ~(sprites_16x16_ ? 3 : 0);
const int sprite_offset = sprites_[target].pattern_number & ~(sprites_16x16_ ? 3 : 0); const int sprite_row = (row_ - sprites_[target].y) & 15;
const int sprite_row = (row_ - sprites_[target].y) & 15; const int sprite_address =
const int sprite_address = sprite_generator_table_address_ + (sprite_offset << 3) + sprite_row + ((subcycle - 4) << 4);
sprite_generator_table_address_ + (sprite_offset << 3) + sprite_row + ((subcycle - 4) << 4); sprites_[target].pattern[subcycle - 4] = ram_[sprite_address];
sprites_[target].pattern[subcycle - 4] = ram_[sprite_address]; } break;
} break;
}
access_pointer_++;
} }
access_pointer_++;
} }
// Four more access windows: no collection.
access_pointer_ = std::min(18, access_slot);
// Then eight access windows fetch the y position for the first eight sprites.
if(access_pointer_ >= 18 && access_pointer_ < 26) {
while(access_pointer_ < 26) {
const int sprite = access_pointer_ - 18;
sprite_locations_[sprite] = ram_[sprite_attribute_table_address_ + (sprite << 2)];
access_pointer_++;
}
}
// The next 128 access slots are video and sprite collection interleaved.
if(access_pointer_ >= 26 && access_pointer_ < 154) {
int end = std::min(154, access_slot);
int row_base = pattern_name_address_;
int pattern_base = pattern_generator_table_address_;
int colour_base = colour_table_address_;
if(screen_mode_ == 1) {
pattern_base &= 0x2000 | ((row_ & 0xc0) << 5);
colour_base &= 0x2000 | ((row_ & 0xc0) << 5);
}
row_base += (row_ << 2)&~31;
// Sprites 0–7: 18–25; then:
// 31, 35, 39 ... 47, 51, 55 ... 63, 67, 71 ... 79, 83, 87 ...
// 95, 99, 103 ... 111, 115, 119 ... 127, 131, 135 ... 143, 147, 151
//
// Relative to 31:
// 0, 4, 8, X, ...
// TODO: optimise this mess.
while(access_pointer_ < end) {
int character_column = ((access_pointer_ - 26) >> 2);
switch(access_pointer_&3) {
case 2:
pattern_name_ = ram_[row_base + character_column];
break;
case 3: {
const int slot = (access_pointer_ - 31) >> 2;
if((slot&3) == 3)
break;
const int sprite = slot - (slot >> 2) + 8;
sprite_locations_[sprite] = ram_[sprite_attribute_table_address_ + (sprite << 2)];
} break;
case 0:
if(screen_mode_ != 1) {
colour_buffer_[character_column] = ram_[colour_base + (pattern_name_ >> 3)];
} else {
colour_buffer_[character_column] = ram_[colour_base + (pattern_name_ << 3) + (row_ & 7)];
}
break;
case 1:
pattern_buffer_[character_column] = ram_[pattern_base + (pattern_name_ << 3) + (row_ & 7)];
break;
}
access_pointer_++;
}
if(access_pointer_ == 154) {
// Pick some sprites to display.
active_sprites_[0] = active_sprites_[1] = active_sprites_[2] = active_sprites_[3] = 0xff;
int slot = 0;
int last_visible = 0;
int sprite_height = 8;
if(sprites_16x16_) sprite_height <<= 1;
if(sprites_magnified_) sprite_height <<= 1;
for(int c = 0; c < 32; ++c) {
// A sprite Y of 208 means "don't scan the list any further".
if(sprite_locations_[c] == 208) break;
// Skip sprite if invisible anyway.
int offset = (row_ - sprite_locations_[c])&255;
if(offset < 0 || offset >= sprite_height) continue;
last_visible = c;
if(slot < 4) {
active_sprites_[slot] = c;
slot++;
} else {
// Set the fifth sprite bit and store the sprite if this is the first encountered.
if(!(status_ & 0x40)) {
status_ |= 0x40;
status_ = static_cast<uint8_t>((status_ & ~31) | c);
}
break;
}
}
if(!(status_ & 0x40)) {
status_ = static_cast<uint8_t>((status_ & ~31) | last_visible);
}
}
}
// Two access windows: no collection.
access_pointer_ = std::min(156, access_slot);
// Fourteen access windows: collect initial sprite information.
if(access_pointer_ >= 156 && access_pointer_ < 170) {
int end = std::min(170, access_slot);
while(access_pointer_ < end) {
const int target = (access_pointer_ - 156) / 6;
const int sprite = active_sprites_[target] & 31;
const int subcycle = access_pointer_ % 6;
// printf("%d: %d %d\n", access_pointer_, target, subcycle);
switch(subcycle) {
case 0: sprites_[target].y = ram_[sprite_attribute_table_address_ + (sprite << 2)]; break;
case 1: sprites_[target].x = ram_[sprite_attribute_table_address_ + (sprite << 2) + 1]; break;
case 2: sprites_[target].pattern_number = ram_[sprite_attribute_table_address_ + (sprite << 2) + 2]; break;
case 3: sprites_[target].colour = ram_[sprite_attribute_table_address_ + (sprite << 2) + 3]; break;
case 4:
case 5: {
const int sprite_offset = sprites_[target].pattern_number & ~(sprites_16x16_ ? 3 : 0);
const int sprite_row = (row_ - sprites_[target].y) & 15;
const int sprite_address =
sprite_generator_table_address_ + (sprite_offset << 3) + sprite_row + ((subcycle - 4) << 4);
sprites_[target].pattern[subcycle - 4] = ram_[sprite_address];
} break;
}
access_pointer_++;
}
}
// There's a single unused access window here.
access_pointer_ = std::min(171, access_slot);
} }
// Four more access windows: no collection.
access_pointer_ = std::min(18, access_slot);
// Then eight access windows fetch the y position for the first eight sprites.
if(access_pointer_ >= 18 && access_pointer_ < 26) {
while(access_pointer_ < 26) {
const int sprite = access_pointer_ - 18;
sprite_locations_[sprite] = ram_[sprite_attribute_table_address_ + (sprite << 2)];
access_pointer_++;
}
}
// The next 128 access slots are video and sprite collection interleaved.
if(access_pointer_ >= 26 && access_pointer_ < 154) {
int end = std::min(154, access_slot);
int row_base = pattern_name_address_;
int pattern_base = pattern_generator_table_address_;
int colour_base = colour_table_address_;
if(screen_mode_ == 1) {
pattern_base &= 0x2000 | ((row_ & 0xc0) << 5);
colour_base &= 0x2000 | ((row_ & 0xc0) << 5);
}
row_base += (row_ << 2)&~31;
// Sprites 0–7: 18–25; then:
// 31, 35, 39 ... 47, 51, 55 ... 63, 67, 71 ... 79, 83, 87 ...
// 95, 99, 103 ... 111, 115, 119 ... 127, 131, 135 ... 143, 147, 151
//
// Relative to 31:
// 0, 4, 8, X, ...
// TODO: optimise this mess.
while(access_pointer_ < end) {
int character_column = ((access_pointer_ - 26) >> 2);
switch(access_pointer_&3) {
case 2:
pattern_names_[character_column] = ram_[row_base + character_column];
break;
case 3: {
const int slot = (access_pointer_ - 31) >> 2;
if((slot&3) == 3)
break;
const int sprite = slot - (slot >> 2) + 8;
sprite_locations_[sprite] = ram_[sprite_attribute_table_address_ + (sprite << 2)];
} break;
case 0:
if(screen_mode_ != 1) {
colour_buffer_[character_column] = ram_[colour_base + (pattern_names_[character_column] >> 3)];
} else {
colour_buffer_[character_column] = ram_[colour_base + (pattern_names_[character_column] << 3) + (row_ & 7)];
}
break;
case 1:
pattern_buffer_[character_column] = ram_[pattern_base + (pattern_names_[character_column] << 3) + (row_ & 7)];
break;
}
access_pointer_++;
}
if(access_pointer_ == 154) {
// Pick some sprites to display.
active_sprites_[0] = active_sprites_[1] = active_sprites_[2] = active_sprites_[3] = 0xff;
int slot = 0;
int last_visible = 0;
int sprite_height = 8;
if(sprites_16x16_) sprite_height <<= 1;
if(sprites_magnified_) sprite_height <<= 1;
for(int c = 0; c < 32; ++c) {
// A sprite Y of 208 means "don't scan the list any further".
if(sprite_locations_[c] == 208) break;
// Skip sprite if invisible anyway.
int offset = (row_ - sprite_locations_[c])&255;
if(offset < 0 || offset >= sprite_height) continue;
last_visible = c;
if(slot < 4) {
active_sprites_[slot] = c;
slot++;
} else {
// Set the fifth sprite bit and store the sprite if this is the first encountered.
if(!(status_ & 0x40)) {
status_ |= 0x40;
status_ = static_cast<uint8_t>((status_ & ~31) | c);
}
break;
}
}
if(!(status_ & 0x40)) {
status_ = static_cast<uint8_t>((status_ & ~31) | last_visible);
}
}
}
// Two access windows: no collection.
access_pointer_ = std::min(156, access_slot);
// Fourteen access windows: collect initial sprite information.
if(access_pointer_ >= 156 && access_pointer_ < 170) {
int end = std::min(170, access_slot);
while(access_pointer_ < end) {
const int target = (access_pointer_ - 156) / 6;
const int sprite = active_sprites_[target] & 31;
const int subcycle = access_pointer_ % 6;
switch(subcycle) {
case 0: sprites_[target].y = ram_[sprite_attribute_table_address_ + (sprite << 2)]; break;
case 1: sprites_[target].x = ram_[sprite_attribute_table_address_ + (sprite << 2) + 1]; break;
case 2: sprites_[target].pattern_number = ram_[sprite_attribute_table_address_ + (sprite << 2) + 2]; break;
case 3: sprites_[target].colour = ram_[sprite_attribute_table_address_ + (sprite << 2) + 3]; break;
case 4:
case 5: {
const int sprite_offset = sprites_[target].pattern_number & ~(sprites_16x16_ ? 3 : 0);
const int sprite_row = (row_ - sprites_[target].y) & 15;
const int sprite_address =
sprite_generator_table_address_ + (sprite_offset << 3) + sprite_row + ((subcycle - 4) << 4);
sprites_[target].pattern[subcycle - 4] = ram_[sprite_address];
} break;
}
access_pointer_++;
}
}
// There's a single unused access window here.
access_pointer_ = std::min(171, access_slot);
break; break;
} }
} }
@ -344,17 +330,29 @@ void TMS9918::run_for(const HalfCycles cycles) {
if(output_column_ < pixels_end) { if(output_column_ < pixels_end) {
switch(line_mode_) { switch(line_mode_) {
case LineMode::Text: case LineMode::Text: {
while(output_column_ < pixels_end) { const uint32_t colours[2] = { palette[background_colour_], palette[text_colour_] };
const int base = (output_column_ - first_pixel_column_);
const int address = base / 6;
const int pattern = pattern_buffer_[address] << (base % 6);
*pixel_target_ = (pattern&0x80) ? palette[text_colour_] : palette[background_colour_]; const int shift = (output_column_ - first_pixel_column_) % 6;
pixel_target_ ++; int byte_column = (output_column_ - first_pixel_column_) / 6;
output_column_ ++; int pattern = pattern_buffer_[byte_column] << shift;
int pixels_left = pixels_end - output_column_;
int length = std::min(pixels_left, 6 - shift);
while(true) {
pixels_left -= length;
while(length--) {
*pixel_target_ = colours[(pattern >> 7)&0x01];
pixel_target_++;
pattern <<= 1;
}
if(!pixels_left) break;
length = std::min(6, pixels_left);
byte_column++;
pattern = pattern_buffer_[byte_column];
} }
break; output_column_ = pixels_end;
} break;
case LineMode::Character: case LineMode::Character:
while(output_column_ < pixels_end) { while(output_column_ < pixels_end) {

3
Components/9918/9918.hpp
View File

@ -93,12 +93,13 @@ class TMS9918 {
} line_mode_ = LineMode::Text; } line_mode_ = LineMode::Text;
int first_pixel_column_, first_right_border_column_; int first_pixel_column_, first_right_border_column_;
uint8_t pattern_names_[40];
uint8_t pattern_buffer_[40]; uint8_t pattern_buffer_[40];
uint8_t colour_buffer_[40]; uint8_t colour_buffer_[40];
uint8_t sprite_locations_[32]; uint8_t sprite_locations_[32];
int active_sprites_[4]; int active_sprites_[4];
int access_pointer_ = 0; int access_pointer_ = 0;
uint8_t pattern_name_ = 0;
struct Sprite { struct Sprite {
uint8_t x, y; uint8_t x, y;