From 8d900cf63605c0d38c0a11536bf5aa1948a6e778 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Sun, 19 Feb 2023 21:52:10 -0500
Subject: [PATCH] Attempt a full collection of Mode 2 sprite properties.
---
Components/9918/Implementation/Fetch.hpp | 121 ++++++++++++++---------
1 file changed, 73 insertions(+), 48 deletions(-)
diff --git a/Components/9918/Implementation/Fetch.hpp b/Components/9918/Implementation/Fetch.hpp
index 584b505fd..0f47ff09b 100644
--- a/Components/9918/Implementation/Fetch.hpp
+++ b/Components/9918/Implementation/Fetch.hpp
@@ -195,50 +195,87 @@ constexpr SpriteMode sprite_mode(ScreenMode screen_mode) {
}
template <Personality personality, SpriteMode mode>
-struct SpriteFetcher {
- using AddressT = typename Base<personality>::AddressT;
+class SpriteFetcher {
+ public:
+ using AddressT = typename Base<personality>::AddressT;
- SpriteFetcher(Base<personality> *base, LineBuffer &buffer, LineBuffer &sprite_selection_buffer, int y) :
- base(base),
- tile_buffer(buffer),
- sprite_selection_buffer(sprite_selection_buffer),
- y(y) {}
+ SpriteFetcher(Base<personality> *base, LineBuffer &buffer, LineBuffer &sprite_selection_buffer, int y) :
+ base(base),
+ tile_buffer(buffer),
+ sprite_selection_buffer(sprite_selection_buffer),
+ y(y) {}
- void fetch_location(int slot, [[maybe_unused]] int name_slot = 0) {
- tile_buffer.active_sprites[slot].x =
- base->ram_[
- base->sprite_attribute_table_address_ & bits<7>(AddressT((tile_buffer.active_sprites[slot].index << 2) | 1))
- ];
+ void fetch_location(int slot, [[maybe_unused]] int name_slot = 0) {
+ fetch_xy(slot);
- if constexpr (mode == SpriteMode::Mode2) {
- base->name_[name_slot] = base->ram_[
+ if constexpr (mode == SpriteMode::Mode2) {
+ fetch_xy(slot + 1);
+
+ base->name_[0] = name(slot);
+ base->name_[1] = name(slot + 1);
+ }
+ }
+
+ void fetch_pattern(int slot) {
+ switch(mode) {
+ case SpriteMode::Mode1:
+ fetch_image(slot, name(slot));
+ break;
+
+ case SpriteMode::Mode2:
+ fetch_image(slot, base->name_[0]);
+ fetch_image(slot + 1, base->name_[1]);
+ break;
+ }
+ }
+
+ void fetch_y(int sprite) {
+ base->posit_sprite(sprite_selection_buffer, sprite, base->ram_[base->sprite_attribute_table_address_ & bits<7>(AddressT(sprite << 2))], y);
+ }
+
+ private:
+ void fetch_xy(int slot) {
+ tile_buffer.active_sprites[slot].x =
+ base->ram_[
+ base->sprite_attribute_table_address_ & bits<7>(AddressT((tile_buffer.active_sprites[slot].index << 2) | 1))
+ ];
+ }
+
+ uint8_t name(int slot) {
+ return base->ram_[
base->sprite_attribute_table_address_ & bits<7>(AddressT((tile_buffer.active_sprites[slot].index << 2) | 2))
] & (base->sprites_16x16_ ? ~3 : ~0);
}
- }
- void fetch_pattern(int slot) {
- const uint8_t name = base->ram_[
- base->sprite_attribute_table_address_ & bits<7>(AddressT((tile_buffer.active_sprites[slot].index << 2) | 2))
- ] & (base->sprites_16x16_ ? ~3 : ~0);
- tile_buffer.active_sprites[slot].image[2] = base->ram_[
- base->sprite_attribute_table_address_ & bits<7>(AddressT((tile_buffer.active_sprites[slot].index << 2) | 3))
- ];
- tile_buffer.active_sprites[slot].x -= (tile_buffer.active_sprites[slot].image[2] & 0x80) >> 2;
+ void fetch_image(int slot, uint8_t name) {
+ const AddressT graphic_location = base->sprite_generator_table_address_ & bits<11>(AddressT((name << 3) | tile_buffer.active_sprites[slot].row));
- const AddressT graphic_location = base->sprite_generator_table_address_ & bits<11>(AddressT((name << 3) | tile_buffer.active_sprites[slot].row));
- tile_buffer.active_sprites[slot].image[0] = base->ram_[graphic_location];
- tile_buffer.active_sprites[slot].image[1] = base->ram_[graphic_location+16];
- }
+ uint8_t colour = 0;
+ switch(mode) {
+ case SpriteMode::Mode1:
+ // Fetch colour from the attribute table, per this sprite's slot.
+ colour =
+ base->ram_[
+ base->sprite_attribute_table_address_ & bits<7>(AddressT((tile_buffer.active_sprites[slot].index << 2) | 3))
+ ];
+ break;
- void fetch_y(int sprite) {
- base->posit_sprite(sprite_selection_buffer, sprite, base->ram_[base->sprite_attribute_table_address_ & bits<7>(AddressT(sprite << 2))], y);
- }
+ case SpriteMode::Mode2: {
+ // Fetch colour from the colour table, per this sprite's name and row.
+ colour = base->ram_[graphic_location & ~512];
+ } break;
+ }
+ tile_buffer.active_sprites[slot].image[2] = colour;
+ tile_buffer.active_sprites[slot].x -= (colour & 0x80) >> 2;
- Base<personality> *const base;
- LineBuffer &tile_buffer;
- LineBuffer &sprite_selection_buffer;
- const int y;
+ tile_buffer.active_sprites[slot].image[0] = base->ram_[graphic_location];
+ tile_buffer.active_sprites[slot].image[1] = base->ram_[graphic_location+16];
+ }
+
+ Base<personality> *const base;
+ LineBuffer &tile_buffer;
+ LineBuffer &sprite_selection_buffer;
+ const int y;
};
template <Personality personality>
@@ -681,16 +718,8 @@ template<ScreenMode mode> void Base<personality>::fetch_yamaha(LineBuffer &line_
// Ensure the compiler can discard character_fetcher in these modes.
break;
- case ScreenMode::Graphics:
- case ScreenMode::MultiColour:
- case ScreenMode::ColouredText:
- sprite_fetcher.fetch_location(Storage<personality>::next_event_->id);
- break;
-
default:
- // TODO: should responsibility for two fetches be in the sprite fetcher?
- sprite_fetcher.fetch_location(Storage<personality>::next_event_->id, 0);
- sprite_fetcher.fetch_location(Storage<personality>::next_event_->id + 1, 1);
+ sprite_fetcher.fetch_location(Storage<personality>::next_event_->id);
break;
}
break;
@@ -703,13 +732,9 @@ template<ScreenMode mode> void Base<personality>::fetch_yamaha(LineBuffer &line_
// Ensure the compiler can discard character_fetcher in these modes.
break;
- case ScreenMode::Graphics:
- case ScreenMode::MultiColour:
- case ScreenMode::ColouredText:
+ default:
sprite_fetcher.fetch_pattern(Storage<personality>::next_event_->id);
break;
-
- default: break;
}
break;