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https://github.com/TomHarte/CLK.git
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Makes substantial optimisations to text mode.
Character optimisations to come.
This commit is contained in:
Thomas Harte
parent
ec266d6c8e
commit
6eedc99286
@ -103,197 +103,183 @@ void TMS9918::run_for(const HalfCycles cycles) {
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const int access_slot = column_ >> 1; // There are only 171 available memory accesses per line.
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switch(line_mode_) {
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case LineMode::Text:
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while(access_pointer_ < access_slot) {
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if(access_pointer_ < 29) {
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access_pointer_ = std::min(29, access_slot);
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}
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if(access_pointer_ >= 29) {
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int row_base = pattern_name_address_ + (row_ >> 3) * 40;
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int character_column = (access_pointer_ - 29) / 3;
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access_pointer_ = std::min(30, access_slot);
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if(access_pointer_ >= 30 && access_pointer_ < 150) {
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const int row_base = pattern_name_address_ + (row_ >> 3) * 40;
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const int start_column = (access_pointer_ - 30) / 3;
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const int end = std::min(150, access_slot);
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const int end = std::min(149, access_slot);
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while(access_pointer_ < end) {
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switch(access_pointer_%3) {
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case 0:
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pattern_buffer_[character_column] = ram_[pattern_generator_table_address_ + (pattern_name_ << 3) + (row_ & 7)];
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character_column++;
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break;
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case 1: break; // TODO: CPU access.
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case 2:
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pattern_name_ = ram_[row_base + character_column];
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break;
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}
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access_pointer_++;
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}
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// Pattern names are collected every third window starting from window 30.
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const int pattern_names_end = (end - 30) / 3;
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for(int column = start_column; column < pattern_names_end; ++column) {
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pattern_names_[column] = ram_[row_base + column];
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}
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if(access_pointer_ >= 149) {
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access_pointer_ = access_slot;
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// Patterns are collected every third window starting from window 32.
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const int pattern_buffer_end = (end - 32) / 3;
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for(int column = start_column; column < pattern_buffer_end; ++column) {
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pattern_buffer_[column] = ram_[pattern_generator_table_address_ + (pattern_names_[column] << 3) + (row_ & 7)];
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}
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}
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break;
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case LineMode::Character:
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while(access_pointer_ < access_slot) {
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// Four access windows: no collection.
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access_pointer_ = std::min(4, access_slot);
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// Four access windows: no collection.
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access_pointer_ = std::min(4, access_slot);
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// Then ten access windows are filled with collection of sprite 3 and 4 details.
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if(access_pointer_ >= 4 && access_pointer_ < 14) {
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// TODO: this repeats the code below.
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int end = std::min(14, access_slot);
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while(access_pointer_ < end) {
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const int offset = access_pointer_ - 2;
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const int target = 2 + (offset / 6);
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const int sprite = active_sprites_[target] & 31;
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const int subcycle = offset % 6;
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// printf("%d: %d %d\n", access_pointer_, target, subcycle);
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switch(subcycle) {
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case 0: sprites_[target].y = ram_[sprite_attribute_table_address_ + (sprite << 2)]; break;
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case 1: sprites_[target].x = ram_[sprite_attribute_table_address_ + (sprite << 2) + 1]; break;
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case 2: sprites_[target].pattern_number = ram_[sprite_attribute_table_address_ + (sprite << 2) + 2]; break;
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case 3: sprites_[target].colour = ram_[sprite_attribute_table_address_ + (sprite << 2) + 3]; break;
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case 4:
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case 5: {
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const int sprite_offset = sprites_[target].pattern_number & ~(sprites_16x16_ ? 3 : 0);
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const int sprite_row = (row_ - sprites_[target].y) & 15;
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const int sprite_address =
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sprite_generator_table_address_ + (sprite_offset << 3) + sprite_row + ((subcycle - 4) << 4);
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sprites_[target].pattern[subcycle - 4] = ram_[sprite_address];
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} break;
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}
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access_pointer_++;
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// Then ten access windows are filled with collection of sprite 3 and 4 details.
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if(access_pointer_ >= 4 && access_pointer_ < 14) {
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// TODO: this repeats the code below.
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int end = std::min(14, access_slot);
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while(access_pointer_ < end) {
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const int offset = access_pointer_ - 2;
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const int target = 2 + (offset / 6);
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const int sprite = active_sprites_[target] & 31;
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const int subcycle = offset % 6;
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switch(subcycle) {
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case 0: sprites_[target].y = ram_[sprite_attribute_table_address_ + (sprite << 2)]; break;
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case 1: sprites_[target].x = ram_[sprite_attribute_table_address_ + (sprite << 2) + 1]; break;
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case 2: sprites_[target].pattern_number = ram_[sprite_attribute_table_address_ + (sprite << 2) + 2]; break;
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case 3: sprites_[target].colour = ram_[sprite_attribute_table_address_ + (sprite << 2) + 3]; break;
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case 4:
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case 5: {
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const int sprite_offset = sprites_[target].pattern_number & ~(sprites_16x16_ ? 3 : 0);
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const int sprite_row = (row_ - sprites_[target].y) & 15;
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const int sprite_address =
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sprite_generator_table_address_ + (sprite_offset << 3) + sprite_row + ((subcycle - 4) << 4);
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sprites_[target].pattern[subcycle - 4] = ram_[sprite_address];
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} break;
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}
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access_pointer_++;
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}
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// Four more access windows: no collection.
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access_pointer_ = std::min(18, access_slot);
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// Then eight access windows fetch the y position for the first eight sprites.
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if(access_pointer_ >= 18 && access_pointer_ < 26) {
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while(access_pointer_ < 26) {
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const int sprite = access_pointer_ - 18;
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sprite_locations_[sprite] = ram_[sprite_attribute_table_address_ + (sprite << 2)];
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access_pointer_++;
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}
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}
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// The next 128 access slots are video and sprite collection interleaved.
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if(access_pointer_ >= 26 && access_pointer_ < 154) {
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int end = std::min(154, access_slot);
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int row_base = pattern_name_address_;
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int pattern_base = pattern_generator_table_address_;
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int colour_base = colour_table_address_;
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if(screen_mode_ == 1) {
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pattern_base &= 0x2000 | ((row_ & 0xc0) << 5);
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colour_base &= 0x2000 | ((row_ & 0xc0) << 5);
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}
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row_base += (row_ << 2)&~31;
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// Sprites 0–7: 18–25; then:
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// 31, 35, 39 ... 47, 51, 55 ... 63, 67, 71 ... 79, 83, 87 ...
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// 95, 99, 103 ... 111, 115, 119 ... 127, 131, 135 ... 143, 147, 151
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//
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// Relative to 31:
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// 0, 4, 8, X, ...
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// TODO: optimise this mess.
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while(access_pointer_ < end) {
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int character_column = ((access_pointer_ - 26) >> 2);
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switch(access_pointer_&3) {
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case 2:
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pattern_name_ = ram_[row_base + character_column];
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break;
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case 3: {
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const int slot = (access_pointer_ - 31) >> 2;
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if((slot&3) == 3)
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break;
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const int sprite = slot - (slot >> 2) + 8;
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sprite_locations_[sprite] = ram_[sprite_attribute_table_address_ + (sprite << 2)];
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} break;
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case 0:
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if(screen_mode_ != 1) {
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colour_buffer_[character_column] = ram_[colour_base + (pattern_name_ >> 3)];
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} else {
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colour_buffer_[character_column] = ram_[colour_base + (pattern_name_ << 3) + (row_ & 7)];
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}
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break;
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case 1:
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pattern_buffer_[character_column] = ram_[pattern_base + (pattern_name_ << 3) + (row_ & 7)];
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break;
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}
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access_pointer_++;
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}
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if(access_pointer_ == 154) {
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// Pick some sprites to display.
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active_sprites_[0] = active_sprites_[1] = active_sprites_[2] = active_sprites_[3] = 0xff;
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int slot = 0;
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int last_visible = 0;
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int sprite_height = 8;
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if(sprites_16x16_) sprite_height <<= 1;
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if(sprites_magnified_) sprite_height <<= 1;
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for(int c = 0; c < 32; ++c) {
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// A sprite Y of 208 means "don't scan the list any further".
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if(sprite_locations_[c] == 208) break;
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// Skip sprite if invisible anyway.
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int offset = (row_ - sprite_locations_[c])&255;
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if(offset < 0 || offset >= sprite_height) continue;
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last_visible = c;
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if(slot < 4) {
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active_sprites_[slot] = c;
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slot++;
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} else {
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// Set the fifth sprite bit and store the sprite if this is the first encountered.
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if(!(status_ & 0x40)) {
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status_ |= 0x40;
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status_ = static_cast<uint8_t>((status_ & ~31) | c);
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}
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break;
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}
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}
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if(!(status_ & 0x40)) {
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status_ = static_cast<uint8_t>((status_ & ~31) | last_visible);
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}
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}
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}
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// Two access windows: no collection.
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access_pointer_ = std::min(156, access_slot);
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// Fourteen access windows: collect initial sprite information.
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if(access_pointer_ >= 156 && access_pointer_ < 170) {
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int end = std::min(170, access_slot);
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while(access_pointer_ < end) {
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const int target = (access_pointer_ - 156) / 6;
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const int sprite = active_sprites_[target] & 31;
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const int subcycle = access_pointer_ % 6;
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// printf("%d: %d %d\n", access_pointer_, target, subcycle);
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switch(subcycle) {
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case 0: sprites_[target].y = ram_[sprite_attribute_table_address_ + (sprite << 2)]; break;
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case 1: sprites_[target].x = ram_[sprite_attribute_table_address_ + (sprite << 2) + 1]; break;
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case 2: sprites_[target].pattern_number = ram_[sprite_attribute_table_address_ + (sprite << 2) + 2]; break;
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case 3: sprites_[target].colour = ram_[sprite_attribute_table_address_ + (sprite << 2) + 3]; break;
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case 4:
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case 5: {
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const int sprite_offset = sprites_[target].pattern_number & ~(sprites_16x16_ ? 3 : 0);
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const int sprite_row = (row_ - sprites_[target].y) & 15;
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const int sprite_address =
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sprite_generator_table_address_ + (sprite_offset << 3) + sprite_row + ((subcycle - 4) << 4);
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sprites_[target].pattern[subcycle - 4] = ram_[sprite_address];
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} break;
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}
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access_pointer_++;
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}
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}
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// There's a single unused access window here.
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access_pointer_ = std::min(171, access_slot);
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}
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// Four more access windows: no collection.
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access_pointer_ = std::min(18, access_slot);
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// Then eight access windows fetch the y position for the first eight sprites.
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if(access_pointer_ >= 18 && access_pointer_ < 26) {
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while(access_pointer_ < 26) {
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const int sprite = access_pointer_ - 18;
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sprite_locations_[sprite] = ram_[sprite_attribute_table_address_ + (sprite << 2)];
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access_pointer_++;
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}
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}
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// The next 128 access slots are video and sprite collection interleaved.
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if(access_pointer_ >= 26 && access_pointer_ < 154) {
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int end = std::min(154, access_slot);
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int row_base = pattern_name_address_;
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int pattern_base = pattern_generator_table_address_;
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int colour_base = colour_table_address_;
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if(screen_mode_ == 1) {
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pattern_base &= 0x2000 | ((row_ & 0xc0) << 5);
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colour_base &= 0x2000 | ((row_ & 0xc0) << 5);
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}
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row_base += (row_ << 2)&~31;
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// Sprites 0–7: 18–25; then:
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// 31, 35, 39 ... 47, 51, 55 ... 63, 67, 71 ... 79, 83, 87 ...
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// 95, 99, 103 ... 111, 115, 119 ... 127, 131, 135 ... 143, 147, 151
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//
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// Relative to 31:
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// 0, 4, 8, X, ...
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// TODO: optimise this mess.
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while(access_pointer_ < end) {
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int character_column = ((access_pointer_ - 26) >> 2);
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switch(access_pointer_&3) {
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case 2:
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pattern_names_[character_column] = ram_[row_base + character_column];
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break;
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case 3: {
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const int slot = (access_pointer_ - 31) >> 2;
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if((slot&3) == 3)
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break;
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const int sprite = slot - (slot >> 2) + 8;
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sprite_locations_[sprite] = ram_[sprite_attribute_table_address_ + (sprite << 2)];
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} break;
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case 0:
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if(screen_mode_ != 1) {
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colour_buffer_[character_column] = ram_[colour_base + (pattern_names_[character_column] >> 3)];
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} else {
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colour_buffer_[character_column] = ram_[colour_base + (pattern_names_[character_column] << 3) + (row_ & 7)];
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}
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break;
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case 1:
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pattern_buffer_[character_column] = ram_[pattern_base + (pattern_names_[character_column] << 3) + (row_ & 7)];
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break;
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}
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access_pointer_++;
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}
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if(access_pointer_ == 154) {
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// Pick some sprites to display.
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active_sprites_[0] = active_sprites_[1] = active_sprites_[2] = active_sprites_[3] = 0xff;
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int slot = 0;
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int last_visible = 0;
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int sprite_height = 8;
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if(sprites_16x16_) sprite_height <<= 1;
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if(sprites_magnified_) sprite_height <<= 1;
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for(int c = 0; c < 32; ++c) {
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// A sprite Y of 208 means "don't scan the list any further".
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if(sprite_locations_[c] == 208) break;
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// Skip sprite if invisible anyway.
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int offset = (row_ - sprite_locations_[c])&255;
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if(offset < 0 || offset >= sprite_height) continue;
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last_visible = c;
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if(slot < 4) {
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active_sprites_[slot] = c;
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slot++;
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} else {
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// Set the fifth sprite bit and store the sprite if this is the first encountered.
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if(!(status_ & 0x40)) {
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status_ |= 0x40;
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status_ = static_cast<uint8_t>((status_ & ~31) | c);
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}
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break;
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}
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}
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if(!(status_ & 0x40)) {
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status_ = static_cast<uint8_t>((status_ & ~31) | last_visible);
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}
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}
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}
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// Two access windows: no collection.
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access_pointer_ = std::min(156, access_slot);
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// Fourteen access windows: collect initial sprite information.
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if(access_pointer_ >= 156 && access_pointer_ < 170) {
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int end = std::min(170, access_slot);
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while(access_pointer_ < end) {
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const int target = (access_pointer_ - 156) / 6;
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const int sprite = active_sprites_[target] & 31;
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const int subcycle = access_pointer_ % 6;
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switch(subcycle) {
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case 0: sprites_[target].y = ram_[sprite_attribute_table_address_ + (sprite << 2)]; break;
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case 1: sprites_[target].x = ram_[sprite_attribute_table_address_ + (sprite << 2) + 1]; break;
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case 2: sprites_[target].pattern_number = ram_[sprite_attribute_table_address_ + (sprite << 2) + 2]; break;
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case 3: sprites_[target].colour = ram_[sprite_attribute_table_address_ + (sprite << 2) + 3]; break;
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case 4:
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case 5: {
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const int sprite_offset = sprites_[target].pattern_number & ~(sprites_16x16_ ? 3 : 0);
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const int sprite_row = (row_ - sprites_[target].y) & 15;
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const int sprite_address =
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sprite_generator_table_address_ + (sprite_offset << 3) + sprite_row + ((subcycle - 4) << 4);
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sprites_[target].pattern[subcycle - 4] = ram_[sprite_address];
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} break;
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}
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access_pointer_++;
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}
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}
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// There's a single unused access window here.
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access_pointer_ = std::min(171, access_slot);
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break;
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}
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}
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@ -344,17 +330,29 @@ void TMS9918::run_for(const HalfCycles cycles) {
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if(output_column_ < pixels_end) {
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switch(line_mode_) {
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case LineMode::Text:
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while(output_column_ < pixels_end) {
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const int base = (output_column_ - first_pixel_column_);
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const int address = base / 6;
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const int pattern = pattern_buffer_[address] << (base % 6);
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case LineMode::Text: {
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const uint32_t colours[2] = { palette[background_colour_], palette[text_colour_] };
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*pixel_target_ = (pattern&0x80) ? palette[text_colour_] : palette[background_colour_];
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pixel_target_ ++;
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output_column_ ++;
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const int shift = (output_column_ - first_pixel_column_) % 6;
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int byte_column = (output_column_ - first_pixel_column_) / 6;
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int pattern = pattern_buffer_[byte_column] << shift;
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int pixels_left = pixels_end - output_column_;
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int length = std::min(pixels_left, 6 - shift);
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while(true) {
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pixels_left -= length;
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while(length--) {
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*pixel_target_ = colours[(pattern >> 7)&0x01];
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pixel_target_++;
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pattern <<= 1;
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}
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if(!pixels_left) break;
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length = std::min(6, pixels_left);
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byte_column++;
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pattern = pattern_buffer_[byte_column];
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}
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break;
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output_column_ = pixels_end;
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} break;
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case LineMode::Character:
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while(output_column_ < pixels_end) {
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@ -93,12 +93,13 @@ class TMS9918 {
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} line_mode_ = LineMode::Text;
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int first_pixel_column_, first_right_border_column_;
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uint8_t pattern_names_[40];
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uint8_t pattern_buffer_[40];
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uint8_t colour_buffer_[40];
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uint8_t sprite_locations_[32];
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int active_sprites_[4];
|
||||
int access_pointer_ = 0;
|
||||
uint8_t pattern_name_ = 0;
|
||||
|
||||
struct Sprite {
|
||||
uint8_t x, y;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user