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6c09abc6cb
Specifically because closer inspection of the TMS modes shows it isn't quite valid to model output of one line as having fully completed prior to fetching of the next. So some sort of extra buffer is required. At which point it is most natural to continue with the logic that each fetch routine is oriented around the fetching process for a single line, and each output routine has the same view, suggesting separate read/write addresses. Something is wrong though, as video data is being output too rapidly (I think) and with occasional sync issues (again: subject to investigation).
984 lines
32 KiB
C++
984 lines
32 KiB
C++
//
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// 9918.cpp
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// Clock Signal
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//
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// Created by Thomas Harte on 25/11/2017.
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// Copyright 2017 Thomas Harte. All rights reserved.
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//
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#include "9918.hpp"
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#include <cassert>
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#include <cstring>
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using namespace TI::TMS;
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namespace {
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const uint8_t StatusInterrupt = 0x80;
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const uint8_t StatusSpriteOverflow = 0x40;
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const int StatusSpriteCollisionShift = 5;
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const uint8_t StatusSpriteCollision = 0x20;
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struct ReverseTable {
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std::uint8_t map[256];
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ReverseTable() {
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for(int c = 0; c < 256; ++c) {
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map[c] = static_cast<uint8_t>(
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((c & 0x80) >> 7) |
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((c & 0x40) >> 5) |
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((c & 0x20) >> 3) |
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((c & 0x10) >> 1) |
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((c & 0x08) << 1) |
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((c & 0x04) << 3) |
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((c & 0x02) << 5) |
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((c & 0x01) << 7)
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);
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}
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}
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} reverse_table;
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}
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Base::Base(Personality p) :
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personality_(p),
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// 342 internal cycles are 228/227.5ths of a line, so 341.25 cycles should be a whole
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// line. Therefore multiply everything by four, but set line length to 1365 rather than 342*4 = 1368.
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crt_(new Outputs::CRT::CRT(1365, 4, Outputs::CRT::DisplayType::NTSC60, 4)) {
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switch(p) {
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case TI::TMS::TMS9918A:
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case TI::TMS::SMSVDP:
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case TI::TMS::GGVDP:
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ram_.resize(16 * 1024);
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break;
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case TI::TMS::V9938:
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ram_.resize(128 * 1024);
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break;
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case TI::TMS::V9958:
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ram_.resize(192 * 1024);
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break;
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}
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if(is_sega_vdp(personality_)) {
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mode_timing_.line_interrupt_position = 65;
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mode_timing_.end_of_frame_interrupt_position.column = 63;
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mode_timing_.end_of_frame_interrupt_position.row = 193;
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}
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// Establish that output is 10 cycles after values have been read.
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// This is definitely correct for the TMS; more research may be
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// necessary for the other implemented VDPs.
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read_pointer_.row = 0;
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read_pointer_.column = 0;
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write_pointer_.row = 0;
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write_pointer_.column = 10; // i.e. 10 cycles ahead of the read pointer.
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}
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TMS9918::TMS9918(Personality p):
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Base(p) {
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// Unimaginatively, this class just passes RGB through to the shader. Investigation is needed
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// into whether there's a more natural form.
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crt_->set_rgb_sampling_function(
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"vec3 rgb_sample(usampler2D sampler, vec2 coordinate)"
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"{"
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"return texture(sampler, coordinate).rgb / vec3(255.0);"
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"}");
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crt_->set_video_signal(Outputs::CRT::VideoSignal::RGB);
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crt_->set_visible_area(Outputs::CRT::Rect(0.055f, 0.025f, 0.9f, 0.9f));
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crt_->set_input_gamma(2.8f);
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// The TMS remains in-phase with the NTSC colour clock; this is an empirical measurement
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// intended to produce the correct relationship between the hard edges between pixels and
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// the colour clock. It was eyeballed rather than derived from any knowledge of the TMS
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// colour burst generator because I've yet to find any.
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crt_->set_immediate_default_phase(0.85f);
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}
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Outputs::CRT::CRT *TMS9918::get_crt() {
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return crt_.get();
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}
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void Base::LineBuffer::reset_sprite_collection() {
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sprites_stopped = false;
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active_sprite_slot = 0;
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for(int c = 0; c < 8; ++c) {
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active_sprites[c].shift_position = 0;
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}
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}
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void Base::posit_sprite(LineBuffer &buffer, int sprite_number, int sprite_position, int screen_row) {
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if(!(status_ & StatusSpriteOverflow)) {
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status_ = static_cast<uint8_t>((status_ & ~0x1f) | (sprite_number & 0x1f));
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}
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if(buffer.sprites_stopped)
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return;
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// const int sprite_position = ram_[sprite_attribute_table_address_ + static_cast<size_t>(sprite_number << 2)];
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// A sprite Y of 208 means "don't scan the list any further".
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if(mode_timing_.allow_sprite_terminator && sprite_position == 208) {
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buffer.sprites_stopped = true;
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return;
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}
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const int sprite_row = (screen_row - sprite_position)&255;
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if(sprite_row < 0 || sprite_row >= sprite_height_) return;
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if(buffer.active_sprite_slot == mode_timing_.maximum_visible_sprites) {
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status_ |= StatusSpriteOverflow;
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return;
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}
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LineBuffer::ActiveSprite &sprite = buffer.active_sprites[buffer.active_sprite_slot];
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sprite.index = sprite_number;
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sprite.row = sprite_row >> (sprites_magnified_ ? 1 : 0);
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++buffer.active_sprite_slot;
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}
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//void Base::get_sprite_contents(int field, int cycles_left, int screen_row) {
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/* int sprite_id = field / 6;
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field %= 6;
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while(true) {
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const int cycles_in_sprite = std::min(cycles_left, 6 - field);
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cycles_left -= cycles_in_sprite;
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const int final_field = cycles_in_sprite + field;
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assert(sprite_id < 4);
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SpriteSet::ActiveSprite &sprite = sprite_sets_[active_sprite_set_].active_sprites[sprite_id];
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if(field < 4) {
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std::memcpy(
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&sprite.info[field],
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&ram_[sprite_attribute_table_address_ + static_cast<size_t>((sprite.index << 2) + field)],
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static_cast<size_t>(std::min(4, final_field) - field));
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}
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field = std::min(4, final_field);
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const int sprite_offset = sprite.info[2] & ~(sprites_16x16_ ? 3 : 0);
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const size_t sprite_address = sprite_generator_table_address_ + static_cast<size_t>(sprite_offset << 3) + sprite.row; // TODO: recalclate sprite.row from screen_row (?)
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while(field < final_field) {
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sprite.image[field - 4] = ram_[sprite_address + static_cast<size_t>(((field - 4) << 4))];
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field++;
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}
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if(!cycles_left) return;
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field = 0;
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sprite_id++;
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}*/
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//}
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void TMS9918::run_for(const HalfCycles cycles) {
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// As specific as I've been able to get:
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// Scanline time is always 228 cycles.
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// PAL output is 313 lines total. NTSC output is 262 lines total.
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// Interrupt is signalled upon entering the lower border.
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// Convert 456 clocked half cycles per line to 342 internal cycles per line;
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// the internal clock is 1.5 times the nominal 3.579545 Mhz that I've advertised
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// for this part. So multiply by three quarters.
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int int_cycles = (cycles.as_int() * 3) + cycles_error_;
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cycles_error_ = int_cycles & 3;
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int_cycles >>= 2;
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if(!int_cycles) return;
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// There are two intertwined processes here, 'writing' (which means writing to the
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// line buffers, i.e. it's everything to do with collecting a line) and 'reading'
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// (which means reading from the line buffers and generating video).
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int write_cycles_pool = int_cycles;
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int read_cycles_pool = int_cycles;
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while(write_cycles_pool || read_cycles_pool) {
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if(write_cycles_pool) {
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// Determine how much writing to do.
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const int write_cycles = std::min(342 - write_pointer_.column, write_cycles_pool);
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const int end_column = write_pointer_.column + write_cycles;
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LineBuffer &line_buffer = line_buffers_[0];//write_pointer_.row & 1];
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// ---------------------------------------
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// Latch scrolling position, if necessary.
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// ---------------------------------------
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if(write_pointer_.column < 61 && end_column >= 61) {
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if(!write_pointer_.row) {
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master_system_.latched_vertical_scroll = master_system_.vertical_scroll;
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}
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line_buffer.latched_horizontal_scroll = master_system_.horizontal_scroll;
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}
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// ------------------------
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// Perform memory accesses.
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// ------------------------
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#define fetch(function) \
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if(final_window < 171) { \
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function<true>(first_window, final_window);\
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} else {\
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function<false>(first_window, final_window);\
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}
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// column_ and end_column are in 342-per-line cycles;
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// adjust them to a count of windows.
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const int first_window = write_pointer_.column >> 1;
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const int final_window = end_column >> 1;
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if(first_window != final_window) {
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switch(line_buffer.line_mode) {
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case LineMode::Text: fetch(fetch_tms_text); break;
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case LineMode::Character: fetch(fetch_tms_character); break;
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case LineMode::SMS: fetch(fetch_sms); break;
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case LineMode::Refresh: fetch(fetch_tms_refresh); break;
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}
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}
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#undef fetch
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// -------------------------------
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// Check for interrupt conditions.
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// -------------------------------
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if(write_pointer_.column < mode_timing_.line_interrupt_position && end_column >= mode_timing_.line_interrupt_position) {
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// The Sega VDP offers a decrementing counter for triggering line interrupts;
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// it is reloaded either when it overflows or upon every non-pixel line after the first.
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// It is otherwise decremented.
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if(is_sega_vdp(personality_)) {
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if(write_pointer_.row >= 0 && write_pointer_.row <= mode_timing_.pixel_lines) {
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--line_interrupt_counter;
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if(line_interrupt_counter == 0xff) {
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line_interrupt_pending_ = true;
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line_interrupt_counter = line_interrupt_target;
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}
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} else {
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line_interrupt_counter = line_interrupt_target;
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}
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}
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// TODO: the V9938 provides line interrupts from direct specification of the target line.
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// So life is easy.
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}
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if(
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write_pointer_.row == mode_timing_.end_of_frame_interrupt_position.row &&
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write_pointer_.column < mode_timing_.end_of_frame_interrupt_position.column &&
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end_column >= mode_timing_.end_of_frame_interrupt_position.column
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) {
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status_ |= StatusInterrupt;
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}
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// -------------
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// Advance time.
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// -------------
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write_pointer_.column = end_column;
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write_cycles_pool -= write_cycles;
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if(write_pointer_.column == 342) {
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write_pointer_.column = 0;
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write_pointer_.row = (write_pointer_.row + 1) % mode_timing_.total_lines;
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line_buffer = line_buffers_[0];//write_pointer_.row & 1];
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// Establish the output mode for the next line.
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set_current_screen_mode();
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// Based on the output mode, pick a line mode.
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line_buffer.first_pixel_output_column = 86;
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line_buffer.next_border_column = 342;
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mode_timing_.maximum_visible_sprites = 4;
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switch(screen_mode_) {
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case ScreenMode::Text:
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line_buffer.line_mode = LineMode::Text;
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line_buffer.first_pixel_output_column = 94;
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line_buffer.next_border_column = 334;
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break;
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case ScreenMode::SMSMode4:
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line_buffer.line_mode = LineMode::SMS;
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mode_timing_.maximum_visible_sprites = 8;
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break;
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default:
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line_buffer.line_mode = LineMode::Character;
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break;
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}
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if(
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(screen_mode_ == ScreenMode::Blank) ||
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(write_pointer_.row >= mode_timing_.pixel_lines && write_pointer_.row != mode_timing_.total_lines-1))
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line_buffer.line_mode = LineMode::Refresh;
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}
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}
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if(read_cycles_pool) {
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// Determine how much time has passed in the remainder of this line, and proceed.
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const int read_cycles = std::min(342 - read_pointer_.column, read_cycles_pool);
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const int end_column = read_pointer_.column + read_cycles;
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LineBuffer &line_buffer = line_buffers_[0];//read_pointer_.row & 1];
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// --------------------
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// Output video stream.
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// --------------------
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#define intersect(left, right, code) \
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{ \
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const int start = std::max(read_pointer_.column, left); \
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const int end = std::min(end_column, right); \
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if(end > start) {\
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code;\
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}\
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}
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if(line_buffer.line_mode == LineMode::Refresh) {
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if(read_pointer_.row >= mode_timing_.first_vsync_line && read_pointer_.row < mode_timing_.first_vsync_line+4) {
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// Vertical sync.
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if(end_column == 342) {
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crt_->output_sync(342 * 4);
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}
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} else {
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// Right border.
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intersect(0, 15, output_border(end - start));
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// Blanking region; total length is 58 cycles,
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// and 58+15 = 73. So output the lot when the
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// cursor passes 73.
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if(read_pointer_.column < 73 && end_column >= 73) {
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crt_->output_blank(8*4);
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crt_->output_sync(26*4);
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crt_->output_blank(2*4);
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crt_->output_default_colour_burst(14*4);
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crt_->output_blank(8*4);
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}
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// Border colour for the rest of the line.
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intersect(73, 342, output_border(end - start));
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}
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} else {
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// Right border.
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intersect(0, 15, output_border(end - start));
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// Blanking region.
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if(read_pointer_.column < 73 && end_column >= 73) {
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crt_->output_blank(8*4);
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crt_->output_sync(26*4);
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crt_->output_blank(2*4);
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crt_->output_default_colour_burst(14*4);
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crt_->output_blank(8*4);
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}
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// Left border.
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intersect(73, line_buffer.first_pixel_output_column, output_border(end - start));
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// Pixel region.
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intersect(
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line_buffer.first_pixel_output_column,
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line_buffer.next_border_column,
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if(start == line_buffer.first_pixel_output_column) {
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pixel_origin_ = pixel_target_ = reinterpret_cast<uint32_t *>(
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crt_->allocate_write_area(static_cast<unsigned int>(line_buffer.next_border_column - line_buffer.first_pixel_output_column))
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);
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}
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if(pixel_target_) {
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const int relative_start = start - line_buffer.first_pixel_output_column;
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const int relative_end = end - line_buffer.first_pixel_output_column;
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switch(line_buffer.line_mode) {
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case LineMode::SMS: draw_sms(relative_start, relative_end); break;
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case LineMode::Character: draw_tms_character(relative_start, relative_end); break;
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case LineMode::Text: draw_tms_text(relative_start, relative_end); break;
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case LineMode::Refresh: break; /* Dealt with elsewhere. */
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}
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}
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if(end == line_buffer.next_border_column) {
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const unsigned int length = static_cast<unsigned int>(line_buffer.next_border_column - line_buffer.first_pixel_output_column);
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crt_->output_data(length * 4, length);
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pixel_origin_ = pixel_target_ = nullptr;
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}
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);
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// Additional right border, if called for.
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if(line_buffer.next_border_column != 342) {
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intersect(line_buffer.next_border_column, 342, output_border(end - start));
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}
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}
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#undef intersect
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// -------------
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// Advance time.
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// -------------
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read_pointer_.column = end_column;
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read_cycles_pool -= read_cycles;
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if(read_pointer_.column == 342) {
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read_pointer_.column = 0;
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read_pointer_.row = (read_pointer_.row + 1) % mode_timing_.total_lines;
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}
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}
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}
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}
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void Base::output_border(int cycles) {
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uint32_t *const pixel_target = reinterpret_cast<uint32_t *>(crt_->allocate_write_area(1));
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if(pixel_target) {
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if(is_sega_vdp(personality_)) {
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*pixel_target = master_system_.colour_ram[16 + background_colour_];
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} else {
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*pixel_target = palette[background_colour_];
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}
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}
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crt_->output_level(static_cast<unsigned int>(cycles) * 4);
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}
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void TMS9918::set_register(int address, uint8_t value) {
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// Writes to address 0 are writes to the video RAM. Store
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// the value and return.
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if(!(address & 1)) {
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write_phase_ = false;
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// Enqueue the write to occur at the next available slot.
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read_ahead_buffer_ = value;
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queued_access_ = MemoryAccess::Write;
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return;
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}
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// Writes to address 1 are performed in pairs; if this is the
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// low byte of a value, store it and wait for the high byte.
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if(!write_phase_) {
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low_write_ = value;
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write_phase_ = true;
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// The initial write should half update the access pointer.
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ram_pointer_ = (ram_pointer_ & 0xff00) | low_write_;
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return;
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}
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// The RAM pointer is always set on a second write, regardless of
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// whether the caller is intending to enqueue a VDP operation.
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ram_pointer_ = (ram_pointer_ & 0x00ff) | static_cast<uint16_t>(value << 8);
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write_phase_ = false;
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if(value & 0x80) {
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switch(personality_) {
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default:
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value &= 0x7;
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break;
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case TI::TMS::SMSVDP:
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if(value & 0x40) {
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master_system_.cram_is_selected = true;
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return;
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}
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value &= 0xf;
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break;
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}
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// This is a write to a register.
|
|
switch(value) {
|
|
case 0:
|
|
if(is_sega_vdp(personality_)) {
|
|
master_system_.vertical_scroll_lock = !!(low_write_ & 0x80);
|
|
master_system_.horizontal_scroll_lock = !!(low_write_ & 0x40);
|
|
master_system_.hide_left_column = !!(low_write_ & 0x20);
|
|
enable_line_interrupts_ = !!(low_write_ & 0x10);
|
|
master_system_.shift_sprites_8px_left = !!(low_write_ & 0x08);
|
|
master_system_.mode4_enable = !!(low_write_ & 0x04);
|
|
}
|
|
mode2_enable_ = !!(low_write_ & 0x02);
|
|
break;
|
|
|
|
case 1:
|
|
blank_display_ = !(low_write_ & 0x40);
|
|
generate_interrupts_ = !!(low_write_ & 0x20);
|
|
mode1_enable_ = !!(low_write_ & 0x10);
|
|
mode3_enable_ = !!(low_write_ & 0x08);
|
|
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;
|
|
break;
|
|
|
|
case 2:
|
|
pattern_name_address_ = size_t((low_write_ & 0xf) << 10) | 0x3ff;
|
|
break;
|
|
|
|
case 3:
|
|
colour_table_address_ = size_t(low_write_ << 6) | 0x1f;
|
|
break;
|
|
|
|
case 4:
|
|
pattern_generator_table_address_ = size_t((low_write_ & 0x07) << 11) | 0x7ff;
|
|
break;
|
|
|
|
case 5:
|
|
sprite_attribute_table_address_ = size_t((low_write_ & 0x7f) << 7) | 0x7f;
|
|
break;
|
|
|
|
case 6:
|
|
sprite_generator_table_address_ = size_t((low_write_ & 0x07) << 11) | 0x7ff;
|
|
break;
|
|
|
|
case 7:
|
|
text_colour_ = low_write_ >> 4;
|
|
background_colour_ = low_write_ & 0xf;
|
|
break;
|
|
|
|
case 8:
|
|
if(is_sega_vdp(personality_)) {
|
|
master_system_.horizontal_scroll = low_write_;
|
|
// printf("Set to %d at %d, %d\n", low_write_, row_, column_);
|
|
}
|
|
break;
|
|
|
|
case 9:
|
|
if(is_sega_vdp(personality_)) {
|
|
master_system_.vertical_scroll = low_write_;
|
|
}
|
|
break;
|
|
|
|
case 10:
|
|
if(is_sega_vdp(personality_)) {
|
|
line_interrupt_target = low_write_;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
// printf("Unknown TMS write: %d to %d\n", low_write_, value);
|
|
break;
|
|
}
|
|
} else {
|
|
// This is an access via the RAM pointer.
|
|
if(!(value & 0x40)) {
|
|
// A read request is enqueued upon setting the address; conversely a write
|
|
// won't be enqueued unless and until some actual data is supplied.
|
|
queued_access_ = MemoryAccess::Read;
|
|
}
|
|
master_system_.cram_is_selected = false;
|
|
}
|
|
}
|
|
|
|
uint8_t TMS9918::get_current_line() {
|
|
// Determine the row to return.
|
|
static const int row_change_position = 62; // This is the proper Master System value; substitute if any other VDPs turn out to have this functionality.
|
|
int source_row =
|
|
(write_pointer_.column < row_change_position)
|
|
? (write_pointer_.row + mode_timing_.total_lines - 1)%mode_timing_.total_lines
|
|
: write_pointer_.row;
|
|
|
|
// This assumes NTSC 192-line. TODO: other modes.
|
|
if(source_row >= 0xdb) source_row -= 6;
|
|
// printf("Current row: %d -> %d\n", row_, source_row);
|
|
|
|
return static_cast<uint8_t>(source_row);
|
|
|
|
/*
|
|
TODO: Full proper sequence of current lines:
|
|
|
|
NTSC 256x192 00-DA, D5-FF
|
|
NTSC 256x224 00-EA, E5-FF
|
|
NTSC 256x240 00-FF, 00-06
|
|
PAL 256x192 00-F2, BA-FF
|
|
PAL 256x224 00-FF, 00-02, CA-FF
|
|
PAL 256x240 00-FF, 00-0A, D2-FF
|
|
*/
|
|
}
|
|
|
|
uint8_t TMS9918::get_latched_horizontal_counter() {
|
|
// Translate from internal numbering, which puts pixel output
|
|
// in the final 256 pixels of 342, to the public numbering,
|
|
// which makes the 256 pixels the first 256 spots, but starts
|
|
// counting at -48, and returns only the top 8 bits of the number.
|
|
int public_counter = latched_column_ - 86;
|
|
if(public_counter < -46) public_counter += 342;
|
|
return uint8_t(public_counter >> 1);
|
|
}
|
|
|
|
void TMS9918::latch_horizontal_counter() {
|
|
latched_column_ = write_pointer_.column;
|
|
}
|
|
|
|
uint8_t TMS9918::get_register(int address) {
|
|
write_phase_ = false;
|
|
|
|
// Reads from address 0 read video RAM, via the read-ahead buffer.
|
|
if(!(address & 1)) {
|
|
// Enqueue the write to occur at the next available slot.
|
|
uint8_t result = read_ahead_buffer_;
|
|
queued_access_ = MemoryAccess::Read;
|
|
return result;
|
|
}
|
|
|
|
// Reads from address 1 get the status register.
|
|
uint8_t result = status_;
|
|
status_ &= ~(StatusInterrupt | StatusSpriteOverflow | StatusSpriteCollision);
|
|
line_interrupt_pending_ = false;
|
|
return result;
|
|
}
|
|
|
|
HalfCycles Base::half_cycles_before_internal_cycles(int internal_cycles) {
|
|
return HalfCycles(((internal_cycles << 2) - cycles_error_) / 3);
|
|
}
|
|
|
|
|
|
HalfCycles TMS9918::get_time_until_interrupt() {
|
|
if(!generate_interrupts_ && !enable_line_interrupts_) return HalfCycles(-1);
|
|
if(get_interrupt_line()) return HalfCycles(0);
|
|
|
|
// Calculate the amount of time until the next end-of-frame interrupt.
|
|
const int frame_length = 342 * mode_timing_.total_lines;
|
|
const int time_until_frame_interrupt =
|
|
(
|
|
((mode_timing_.end_of_frame_interrupt_position.row * 342) + mode_timing_.end_of_frame_interrupt_position.column + frame_length) -
|
|
((write_pointer_.row * 342) + write_pointer_.column)
|
|
) % frame_length;
|
|
|
|
if(!enable_line_interrupts_) return half_cycles_before_internal_cycles(time_until_frame_interrupt);
|
|
|
|
// Calculate the row upon which the next line interrupt will occur;
|
|
int next_line_interrupt_row = -1;
|
|
|
|
if(is_sega_vdp(personality_)) {
|
|
// If there is still time for a line interrupt this frame, that'll be it;
|
|
// otherwise it'll be on the next frame, supposing there's ever time for
|
|
// it at all.
|
|
if(write_pointer_.row+line_interrupt_counter <= mode_timing_.pixel_lines) {
|
|
next_line_interrupt_row = write_pointer_.row+line_interrupt_counter;
|
|
} else {
|
|
if(line_interrupt_target <= mode_timing_.pixel_lines)
|
|
next_line_interrupt_row = mode_timing_.total_lines + line_interrupt_target;
|
|
}
|
|
}
|
|
|
|
// If there's actually no interrupt upcoming, despite being enabled, either return
|
|
// the frame end interrupt or no interrupt pending as appropriate.
|
|
if(next_line_interrupt_row == -1) {
|
|
return generate_interrupts_ ?
|
|
half_cycles_before_internal_cycles(time_until_frame_interrupt) :
|
|
HalfCycles(-1);
|
|
}
|
|
|
|
// Figure out the number of internal cycles until the next line interrupt, which is the amount
|
|
// of time to the next tick over and then next_line_interrupt_row - row_ lines further.
|
|
int local_cycles_until_next_tick = (mode_timing_.line_interrupt_position - write_pointer_.column + 342) % 342;
|
|
if(!local_cycles_until_next_tick) local_cycles_until_next_tick += 342;
|
|
const int local_cycles_until_line_interrupt = local_cycles_until_next_tick + (next_line_interrupt_row - write_pointer_.row) * 342;
|
|
|
|
if(!generate_interrupts_) return half_cycles_before_internal_cycles(time_until_frame_interrupt);
|
|
|
|
// Return whichever interrupt is closer.
|
|
return half_cycles_before_internal_cycles(std::min(local_cycles_until_line_interrupt, time_until_frame_interrupt));
|
|
}
|
|
|
|
bool TMS9918::get_interrupt_line() {
|
|
return ((status_ & StatusInterrupt) && generate_interrupts_) || (enable_line_interrupts_ && line_interrupt_pending_);
|
|
}
|
|
|
|
// MARK: -
|
|
|
|
void Base::draw_tms_character(int start, int end) {
|
|
// if(!start) printf("\n");
|
|
// printf("%d to %d | ", start, end);
|
|
// for(int c = start; c < end; ++c) {
|
|
// pixel_target_[c] = static_cast<uint32_t>(c * 0x01010101);
|
|
// }
|
|
/*
|
|
|
|
// --------------
|
|
// Output pixels.
|
|
// --------------
|
|
|
|
|
|
case LineMode::Character: {
|
|
// If this is the start of the visible area, seed sprite shifter positions.
|
|
SpriteSet &sprite_set = sprite_sets_[active_sprite_set_ ^ 1];
|
|
if(output_column_ == first_pixel_column_) {
|
|
int c = sprite_set.active_sprite_slot;
|
|
while(c--) {
|
|
SpriteSet::ActiveSprite &sprite = sprite_set.active_sprites[c];
|
|
sprite.shift_position = -sprite.info[1];
|
|
if(sprite.info[3] & 0x80) {
|
|
sprite.shift_position += 32;
|
|
if(sprite.shift_position > 0 && !sprites_magnified_)
|
|
sprite.shift_position *= 2;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Paint the background tiles.
|
|
const int pixels_left = pixels_end - output_column_;
|
|
if(current_mode_ == ScreenMode::MultiColour) {
|
|
int pixel_location = output_column_ - first_pixel_column_;
|
|
for(int c = 0; c < pixels_left; ++c) {
|
|
pixel_target_[c] = palette[
|
|
(pattern_buffer_[(pixel_location + c) >> 3] >> (((pixel_location + c) & 4)^4)) & 15
|
|
];
|
|
}
|
|
pixel_target_ += pixels_left;
|
|
} else {
|
|
const int shift = (output_column_ - first_pixel_column_) & 7;
|
|
int byte_column = (output_column_ - first_pixel_column_) >> 3;
|
|
|
|
int length = std::min(pixels_left, 8 - shift);
|
|
|
|
int pattern = reverse_table.map[pattern_buffer_[byte_column]] >> shift;
|
|
uint8_t colour = colour_buffer_[byte_column];
|
|
uint32_t colours[2] = {
|
|
palette[(colour & 15) ? (colour & 15) : background_colour_],
|
|
palette[(colour >> 4) ? (colour >> 4) : background_colour_]
|
|
};
|
|
|
|
int background_pixels_left = pixels_left;
|
|
while(true) {
|
|
background_pixels_left -= length;
|
|
for(int c = 0; c < length; ++c) {
|
|
pixel_target_[c] = colours[pattern&0x01];
|
|
pattern >>= 1;
|
|
}
|
|
pixel_target_ += length;
|
|
|
|
if(!background_pixels_left) break;
|
|
length = std::min(8, background_pixels_left);
|
|
byte_column++;
|
|
|
|
pattern = reverse_table.map[pattern_buffer_[byte_column]];
|
|
colour = colour_buffer_[byte_column];
|
|
colours[0] = palette[(colour & 15) ? (colour & 15) : background_colour_];
|
|
colours[1] = palette[(colour >> 4) ? (colour >> 4) : background_colour_];
|
|
}
|
|
}
|
|
|
|
// Paint sprites and check for collisions, but only if at least one sprite is active
|
|
// on this line.
|
|
if(sprite_set.active_sprite_slot) {
|
|
int sprite_pixels_left = pixels_left;
|
|
const int shift_advance = sprites_magnified_ ? 1 : 2;
|
|
|
|
static const uint32_t sprite_colour_selection_masks[2] = {0x00000000, 0xffffffff};
|
|
static const int colour_masks[16] = {0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
|
|
|
|
while(sprite_pixels_left--) {
|
|
// sprite_colour is the colour that's going to reach the display after sprite logic has been
|
|
// applied; by default assume that nothing is going to be drawn.
|
|
uint32_t sprite_colour = pixel_base_[output_column_ - first_pixel_column_];
|
|
|
|
// The sprite_mask is used to keep track of whether two sprites have both sought to output
|
|
// a pixel at the same location, and to feed that into the status register's sprite
|
|
// collision bit.
|
|
int sprite_mask = 0;
|
|
|
|
int c = sprite_set.active_sprite_slot;
|
|
while(c--) {
|
|
SpriteSet::ActiveSprite &sprite = sprite_set.active_sprites[c];
|
|
|
|
if(sprite.shift_position < 0) {
|
|
sprite.shift_position++;
|
|
continue;
|
|
} else if(sprite.shift_position < 32) {
|
|
int mask = sprite.image[sprite.shift_position >> 4] << ((sprite.shift_position&15) >> 1);
|
|
mask = (mask >> 7) & 1;
|
|
|
|
// Ignore the right half of whatever was collected if sprites are not in 16x16 mode.
|
|
if(sprite.shift_position < (sprites_16x16_ ? 32 : 16)) {
|
|
// If any previous sprite has been painted in this column and this sprite
|
|
// has this pixel set, set the sprite collision status bit.
|
|
status_ |= (mask & sprite_mask) << StatusSpriteCollisionShift;
|
|
sprite_mask |= mask;
|
|
|
|
// Check that the sprite colour is not transparent
|
|
mask &= colour_masks[sprite.info[3]&15];
|
|
sprite_colour = (sprite_colour & sprite_colour_selection_masks[mask^1]) | (palette[sprite.info[3]&15] & sprite_colour_selection_masks[mask]);
|
|
}
|
|
|
|
sprite.shift_position += shift_advance;
|
|
}
|
|
}
|
|
|
|
// Output whichever sprite colour was on top.
|
|
pixel_base_[output_column_ - first_pixel_column_] = sprite_colour;
|
|
output_column_++;
|
|
}
|
|
}
|
|
|
|
output_column_ = pixels_end;
|
|
} break;
|
|
}
|
|
|
|
|
|
}*/
|
|
}
|
|
|
|
void Base::draw_tms_text(int start, int end) {
|
|
LineBuffer &line_buffer = line_buffers_[0];//read_pointer_.row & 1];
|
|
const uint32_t colours[2] = { palette[background_colour_], palette[text_colour_] };
|
|
|
|
const int shift = start % 6;
|
|
int byte_column = start / 6;
|
|
int pattern = reverse_table.map[line_buffer.patterns[byte_column][0]] >> shift;
|
|
int pixels_left = end - start;
|
|
int length = std::min(pixels_left, 6 - shift);
|
|
while(true) {
|
|
pixels_left -= length;
|
|
for(int c = 0; c < length; ++c) {
|
|
pixel_target_[c] = colours[pattern&0x01];
|
|
pattern >>= 1;
|
|
}
|
|
pixel_target_ += length;
|
|
|
|
if(!pixels_left) break;
|
|
length = std::min(6, pixels_left);
|
|
byte_column++;
|
|
pattern = reverse_table.map[line_buffer.patterns[byte_column][0]];
|
|
}
|
|
}
|
|
|
|
void Base::draw_sms(int start, int end) {
|
|
LineBuffer &line_buffer = line_buffers_[0];//read_pointer_.row & 1];
|
|
int colour_buffer[256];
|
|
|
|
/*
|
|
Add extra border for any pixels that fall before the fine scroll.
|
|
*/
|
|
int tile_start = start, tile_end = end;
|
|
int tile_offset = start;
|
|
if(read_pointer_.row >= 16 || !master_system_.horizontal_scroll_lock) {
|
|
for(int c = start; c < (line_buffer.latched_horizontal_scroll & 7); ++c) {
|
|
colour_buffer[c] = 16 + background_colour_;
|
|
++tile_offset;
|
|
}
|
|
|
|
// Remove the border area from that to which tiles will be drawn.
|
|
tile_start = std::max(start - (line_buffer.latched_horizontal_scroll & 7), 0);
|
|
tile_end = std::max(end - (line_buffer.latched_horizontal_scroll & 7), 0);
|
|
}
|
|
|
|
|
|
uint32_t pattern;
|
|
uint8_t *const pattern_index = reinterpret_cast<uint8_t *>(&pattern);
|
|
|
|
/*
|
|
Add background tiles; these will fill the colour_buffer with values in which
|
|
the low five bits are a palette index, and bit six is set if this tile has
|
|
priority over sprites.
|
|
*/
|
|
if(tile_start < end) {
|
|
const int shift = tile_start & 7;
|
|
int byte_column = tile_start >> 3;
|
|
int pixels_left = tile_end - tile_start;
|
|
int length = std::min(pixels_left, 8 - shift);
|
|
|
|
pattern = *reinterpret_cast<const uint32_t *>(line_buffer.patterns[byte_column]);
|
|
if(line_buffer.names[byte_column].flags&2)
|
|
pattern >>= shift;
|
|
else
|
|
pattern <<= shift;
|
|
|
|
while(true) {
|
|
const int palette_offset = (line_buffer.names[byte_column].flags&0x18) << 1;
|
|
if(line_buffer.names[byte_column].flags&2) {
|
|
for(int c = 0; c < length; ++c) {
|
|
colour_buffer[tile_offset] =
|
|
((pattern_index[3] & 0x01) << 3) |
|
|
((pattern_index[2] & 0x01) << 2) |
|
|
((pattern_index[1] & 0x01) << 1) |
|
|
((pattern_index[0] & 0x01) << 0) |
|
|
palette_offset;
|
|
++tile_offset;
|
|
pattern >>= 1;
|
|
}
|
|
} else {
|
|
for(int c = 0; c < length; ++c) {
|
|
colour_buffer[tile_offset] =
|
|
((pattern_index[3] & 0x80) >> 4) |
|
|
((pattern_index[2] & 0x80) >> 5) |
|
|
((pattern_index[1] & 0x80) >> 6) |
|
|
((pattern_index[0] & 0x80) >> 7) |
|
|
palette_offset;
|
|
++tile_offset;
|
|
pattern <<= 1;
|
|
}
|
|
}
|
|
|
|
pixels_left -= length;
|
|
if(!pixels_left) break;
|
|
|
|
length = std::min(8, pixels_left);
|
|
byte_column++;
|
|
pattern = *reinterpret_cast<const uint32_t *>(line_buffer.patterns[byte_column]);
|
|
}
|
|
}
|
|
|
|
/*
|
|
Apply sprites (if any).
|
|
*/
|
|
if(line_buffer.active_sprite_slot) {
|
|
int sprite_buffer[256];
|
|
int sprite_collision = 0;
|
|
memset(&sprite_buffer[start], 0, size_t(end - start)*sizeof(int));
|
|
|
|
// Draw all sprites into the sprite buffer.
|
|
for(int index = line_buffer.active_sprite_slot - 1; index >= 0; --index) {
|
|
LineBuffer::ActiveSprite &sprite = line_buffer.active_sprites[index];
|
|
if(sprite.shift_position < 16) {
|
|
const int pixel_start = std::max(start, sprite.x);
|
|
|
|
// TODO: it feels like the work below should be simplifiable;
|
|
// the double shift in particular, and hopefully the variable shift.
|
|
for(int c = pixel_start; c < end && sprite.shift_position < 16; ++c) {
|
|
const int shift = (sprite.shift_position >> 1);
|
|
const int sprite_colour =
|
|
(((sprite.image[3] << shift) & 0x80) >> 4) |
|
|
(((sprite.image[2] << shift) & 0x80) >> 5) |
|
|
(((sprite.image[1] << shift) & 0x80) >> 6) |
|
|
(((sprite.image[0] << shift) & 0x80) >> 7);
|
|
|
|
if(sprite_colour) {
|
|
sprite_collision |= sprite_buffer[c];
|
|
sprite_buffer[c] = sprite_colour | 0x10;
|
|
}
|
|
|
|
sprite.shift_position += sprites_magnified_ ? 1 : 2;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Draw the sprite buffer onto the colour buffer, wherever the tile map doesn't have
|
|
// priority (or is transparent).
|
|
for(int c = start; c < end; ++c) {
|
|
if(
|
|
sprite_buffer[c] &&
|
|
(!(colour_buffer[c]&0x20) || !(colour_buffer[c]&0xf))
|
|
) colour_buffer[c] = sprite_buffer[c];
|
|
}
|
|
|
|
if(sprite_collision)
|
|
status_ |= StatusSpriteCollision;
|
|
}
|
|
|
|
// Map from the 32-colour buffer to real output pixels.
|
|
for(int c = start; c < end; ++c) {
|
|
pixel_target_[c] = master_system_.colour_ram[colour_buffer[c] & 0x1f];
|
|
}
|
|
|
|
// If the VDP is set to hide the left column and this is the final call that'll come
|
|
// this line, hide it.
|
|
if(end == 256) {
|
|
if(master_system_.hide_left_column) {
|
|
pixel_origin_[0] = pixel_origin_[1] = pixel_origin_[2] = pixel_origin_[3] =
|
|
pixel_origin_[4] = pixel_origin_[5] = pixel_origin_[6] = pixel_origin_[7] =
|
|
master_system_.colour_ram[16 + background_colour_];
|
|
}
|
|
}
|
|
}
|