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-rw-r--r--lib/nes/ppu.hh279
1 files changed, 0 insertions, 279 deletions
diff --git a/lib/nes/ppu.hh b/lib/nes/ppu.hh
deleted file mode 100644
index afc295c..0000000
--- a/lib/nes/ppu.hh
+++ /dev/null
@@ -1,279 +0,0 @@
-#pragma once
-
-#include "nes/util/cycle-count.hh"
-
-namespace nes
-{
- class address;
- class cpu;
- class cartridge;
- class display;
- class rgb;
- struct snapshot;
-
- class ppu
- {
- static constexpr auto sprite_max_count = unsigned{ 64 };
- static constexpr auto vram_size = std::size_t{ 0x800 };
- static constexpr auto oam_size = std::size_t{ sprite_max_count * 4 };
- static constexpr auto palette_buffer_size = std::size_t{ 0x20 };
- static constexpr auto tile_size = unsigned{ 8 };
- // Writes to some registers are ignored until this clock cycle.
- static constexpr auto boot_up_cycles = cycle_count::from_ppu(29658);
-
- enum class bitplane : unsigned { _0, _1 };
- enum class palette : unsigned { _0, _1, _2, _3 };
- enum class palette_color : unsigned { _0, _1, _2, _3 };
- enum class name_table : unsigned { _0, _1, _2, _3 };
- enum class role : unsigned { background, foreground };
- enum class pattern_table : unsigned { _0, _1 };
- enum class vram_increment : unsigned { forward, downward };
- enum class sprite_size : unsigned { single_height, double_height };
- enum class tile : std::uint8_t {};
- enum class color : std::uint8_t {};
-
-#define BITFIELD_VALIDATE(mask, offset_from_right) \
- static_assert((mask & (1 << offset_from_right)) != 0); \
- static_assert(offset_from_right == 0 || (mask & (1 << (offset_from_right - 1))) == 0);
-#define BITFIELD_VALUE(name, base, mask, offset_from_right) \
- BITFIELD_VALIDATE(mask, offset_from_right) \
- auto get_##name() const -> unsigned { return (base & mask) >> offset_from_right; } \
- auto set_##name(unsigned const v) -> void { base = (base & ~mask) | ((v << offset_from_right) & mask); }
-#define BITFIELD_ENUM(name, type, base, mask, offset_from_right) \
- BITFIELD_VALIDATE(mask, offset_from_right) \
- auto get_##name() const -> type { return static_cast<type>((base & mask) >> offset_from_right); } \
- auto set_##name(type const v) -> void { base = (base & ~mask) | ((static_cast<unsigned>(v) << offset_from_right) & mask); }
-#define BITFIELD_FLAG(name, base, mask, offset_from_right) \
- BITFIELD_VALIDATE(mask, offset_from_right) \
- auto get_##name() const -> bool { return base & mask; } \
- auto set_##name(unsigned const v) -> void { base = (base & ~mask) | (v ? mask : 0); }
-
- struct color_index
- {
- BITFIELD_ENUM(color, palette_color, value, 0b00000011, 0)
- BITFIELD_ENUM(palette, palette, value, 0b00001100, 2)
- BITFIELD_ENUM(role, role, value, 0b00010000, 4)
-
- std::uint8_t value{};
-
- color_index() = default;
-
- explicit color_index(std::uint8_t const value)
- : value{ value }
- {
- }
- };
-
- struct sprite
- {
- // Tile index (and pattern table) for sprites
- BITFIELD_ENUM(large_pattern_table, pattern_table, value[1], 0b00000001, 0)
- BITFIELD_ENUM(large_top_tile, tile, value[1], 0b11111110, 1)
- BITFIELD_ENUM(small_tile, tile, value[1], 0b11111111, 0)
-
- // Attributes
- BITFIELD_ENUM(palette, palette, value[2], 0b00000011, 0)
- BITFIELD_FLAG(behind_background, value[2], 0b00100000, 5)
- BITFIELD_FLAG(flip_horizontal, value[2], 0b01000000, 6)
- BITFIELD_FLAG(flip_vertical, value[2], 0b10000000, 7)
-
- auto get_y() const -> std::uint8_t { return value[0]; }
- auto get_tile_index() const -> std::uint8_t { return value[1]; }
- auto get_attributes() const -> std::uint8_t { return value[2]; }
- auto get_x() const -> std::uint8_t { return value[3]; }
-
- auto set_y(std::uint8_t const v) -> void { value[0] = v; }
- auto set_tile_index(std::uint8_t const v) -> void { value[1] = v; }
- auto set_attributes(std::uint8_t const v) -> void { value[2] = v; }
- auto set_x(std::uint8_t const v) -> void { value[3] = v; }
-
- std::uint8_t value[4]{};
-
- explicit sprite() = default;
-
- explicit sprite(std::uint8_t const* data)
- : value{ data[0], data[1], data[2], data[3] }
- {
- }
- };
-
- struct tile_row
- {
- color_index colors[tile_size]{};
- };
-
- struct evaluated_sprite
- {
- tile_row pattern;
- std::uint8_t x{ 0 };
- bool is_in_front{ false };
- bool is_sprite_zero{ false };
- };
-
- cycle_count current_cycles_;
- cpu& cpu_;
- cartridge& cartridge_;
- display& display_;
- std::uint8_t vram_[vram_size]{};
- std::uint8_t oam_[oam_size]{};
- color palette_buffer_[palette_buffer_size]
- {
- color{ 0x09 }, color{ 0x01 }, color{ 0x00 }, color{ 0x01 },
- color{ 0x00 }, color{ 0x02 }, color{ 0x02 }, color{ 0x0D },
- color{ 0x08 }, color{ 0x10 }, color{ 0x08 }, color{ 0x24 },
- color{ 0x00 }, color{ 0x00 }, color{ 0x04 }, color{ 0x2C },
- color{ 0x09 }, color{ 0x01 }, color{ 0x34 }, color{ 0x03 },
- color{ 0x00 }, color{ 0x04 }, color{ 0x00 }, color{ 0x14 },
- color{ 0x08 }, color{ 0x3A }, color{ 0x00 }, color{ 0x02 },
- color{ 0x00 }, color{ 0x20 }, color{ 0x2C }, color{ 0x08 },
- };
- std::uint8_t latch_{}; // The last read/written IO register value, returned when reading write-only registers.
- struct
- {
- BITFIELD_FLAG(sprite_overflow, value, 0b00100000, 5)
- BITFIELD_FLAG(sprite_zero_hit, value, 0b01000000, 6)
- BITFIELD_FLAG(vblank, value, 0b10000000, 7)
-
- // Set the remaining (unused) bits based on the given value.
- auto set_remaining(std::uint8_t const v) -> void { value = (value & ~0b00011111) | (v & 0b00011111); }
-
- std::uint8_t value{ 0b00000000 };
- } status_{};
- struct
- {
- // Base nametable address.
- BITFIELD_ENUM(base_name_table, name_table, value, 0b00000011, 0)
- // How VRAM addresses should be incremented each read/write.
- BITFIELD_ENUM(vram_increment, vram_increment, value, 0b00000100, 2)
- // Sprite pattern table address for 8x8 sprites.
- BITFIELD_ENUM(sprite_pattern_table, pattern_table, value, 0b00001000, 3)
- // Background pattern table address.
- BITFIELD_ENUM(background_pattern_table, pattern_table, value, 0b00010000, 4)
- // The size of the sprites used (i.e. single-height or double-height).
- BITFIELD_ENUM(sprite_size, sprite_size, value, 0b00100000, 5)
- // PPU master/slave select.
- BITFIELD_FLAG(enable_ext_pin, value, 0b01000000, 6)
- // Enable/disable vblank NMI.
- BITFIELD_FLAG(vblank_nmi, value, 0b10000000, 7)
-
- std::uint8_t value{ 0b00000000 };
- } control_{};
- struct
- {
- // Enable/disable grayscale.
- BITFIELD_FLAG(grayscale, value, 0b00000001, 0)
- // Show background in leftmost 8 pixels of screen.
- BITFIELD_FLAG(show_background_start, value, 0b00000010, 1)
- // Show sprites in leftmost 8 pixels of screen.
- BITFIELD_FLAG(show_sprites_start, value, 0b00000100, 2)
- // Enable background rendering.
- BITFIELD_FLAG(enable_background, value, 0b00001000, 3)
- // Enable sprite rendering.
- BITFIELD_FLAG(enable_sprites, value, 0b00010000, 4)
- // Emphasize red.
- BITFIELD_FLAG(emphasize_red, value, 0b00100000, 5)
- // Emphasize green.
- BITFIELD_FLAG(emphasize_green, value, 0b01000000, 6)
- // Emphasize blue.
- BITFIELD_FLAG(emphasize_blue, value, 0b10000000, 7)
-
- std::uint8_t value{ 0b00000000 };
- } mask_{};
- struct
- {
- // See https://www.nesdev.org/wiki/PPU_scrolling#PPU_internal_registers
- struct
- {
- // Scroll position
- BITFIELD_VALUE(coarse_x, value, 0b0000000000011111, 0)
- BITFIELD_VALUE(coarse_y, value, 0b0000001111100000, 5)
- BITFIELD_ENUM(name_table, name_table, value, 0b0000110000000000, 10)
- BITFIELD_VALUE(horizontal_name_table, value, 0b0000010000000000, 10)
- BITFIELD_VALUE(vertical_name_table, value, 0b0000100000000000, 11)
- BITFIELD_VALUE(tile_address, value, 0b0000111111111111, 0)
- BITFIELD_VALUE(fine_y, value, 0b0111000000000000, 12)
-
- // Address
- BITFIELD_VALUE(address_low, value, 0b0000000011111111, 0)
- BITFIELD_VALUE(address_high, value, 0b0111111100000000, 8)
-
- std::uint16_t value{};
- } v{}, t{}; // Current and temporary VRAM address and scroll position (15 bits)
- std::uint8_t x{}; // Fine X scroll (3 bits)
- bool w{}; // Second write toggle (1 bit)
- } internal_{};
- std::uint8_t oamaddr_{}; // Address accessed by IO registers
- std::uint8_t ppudata_read_buffer_{}; // Delays PPUDATA reads by one.
- unsigned scanline_{ 240 };
- unsigned scanline_cycle_{ 340 };
- bool even_frame_{ true };
- tile_row current_background_{};
- tile_row next_background_{};
- struct
- {
- tile tile{ 0 };
- palette palette{ 0 };
- std::uint8_t bitplane_0{ 0 };
- std::uint8_t bitplane_1{ 0 };
- } fetch_cycle_{}; // Data populated during the fetch cycle.
- evaluated_sprite sprites_[8]{}; // Evaluated sprites.
- unsigned sprite_count_{ 0 }; // Number of evaluated sprites in sprites_.
-
-#undef BITFIELD_VALIDATE
-#undef BITFIELD_VALUE
-#undef BITFIELD_ENUM
-#undef BITFIELD_FLAG
-
- public:
- explicit ppu(cpu&, cartridge&, display&);
-
- ppu(ppu const&) = delete;
- ppu(ppu&&) = delete;
- auto operator=(ppu const&) -> ppu& = delete;
- auto operator=(ppu&&) -> ppu& = delete;
-
- auto get_cycles() const -> cycle_count { return current_cycles_; }
- auto build_snapshot(snapshot&) -> void;
- auto step() -> void;
-
- // Memory access
-
- auto read8(address) -> std::uint8_t;
- auto write8(address, std::uint8_t) -> void;
-
- // IO registers
-
- auto read_latch() -> std::uint8_t;
- auto read_ppustatus() -> std::uint8_t;
- auto read_oamdata() -> std::uint8_t;
- auto read_ppudata() -> std::uint8_t;
-
- auto write_latch(std::uint8_t) -> void;
- auto write_ppuctrl(std::uint8_t) -> void;
- auto write_ppuscroll(std::uint8_t) -> void;
- auto write_ppumask(std::uint8_t) -> void;
- auto write_ppuaddr(std::uint8_t) -> void;
- auto write_ppudata(std::uint8_t) -> void;
- auto write_oamaddr(std::uint8_t) -> void;
- auto write_oamdata(std::uint8_t) -> void;
- auto write_oamdma(std::uint8_t) -> void;
-
- private:
- auto render_pixel() -> void;
- auto evaluate_sprites() -> void;
- auto fetch_sprite_pattern(sprite, unsigned row) -> tile_row;
-
- // Helpers
-
- auto increment_vram() -> void;
- auto increment_x() -> void;
- auto increment_y() -> void;
- auto copy_x() -> void;
- auto copy_y() -> void;
- auto get_sprite_height() const -> unsigned;
- auto get_tile_bitplane(pattern_table, tile, unsigned row, bitplane) -> std::uint8_t;
- auto get_tile_row(palette, std::uint8_t bitplane_0, std::uint8_t bitplane_1) const -> tile_row;
- auto ref_color(color_index) -> color&;
- auto resolve_color(color) const -> rgb;
- };
-} // namespace nes \ No newline at end of file
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