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restructureing

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This commit is contained in:
Daniel Bauer
2020-01-22 10:20:29 +01:00
parent b1a996f009
commit b3efd0363d
1 changed files with 48 additions and 40 deletions
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88
src/nes/ppubus.rs
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@@ -31,19 +31,49 @@ impl PPUBus {
pub fn insert_cartridge(&mut self, c: Rc<RefCell<Cartridge>>) {
self.cartridge = Some(c);
}
// map palette addr to internal memory array index
fn map_palette_addr(&self, addr: Addr) -> usize {
let mut rel_addr = addr - 0x3F00;
rel_addr = rel_addr % 0x0020;
if rel_addr == 0x0010 { rel_addr = 0x0000 }
if rel_addr == 0x0014 { rel_addr = 0x0004 }
if rel_addr == 0x0018 { rel_addr = 0x0008 }
if rel_addr == 0x001C { rel_addr = 0x000C }
rel_addr as usize
}
// maps a pattern table address to the index of the internal array
fn map_pattern_table_addr(&self, addr: Addr) -> (usize, usize) {
let table = if addr < 0x1000 { 0 } else { 1 };
let rel_addr = addr % 0x1000;
(table as usize, rel_addr as usize)
}
// maps a nametable address to the corresponding index in the memory
// array
fn map_nametable_addr(&self, addr: Addr) -> (usize, usize) {
let table = if addr < 0x2400 {
0
} else if addr < 0x2800 {
1
} else if addr < 0x2C00 {
2
} else {
3
};
let rel_addr = (addr - 0x2000) % 0x400;
(table as usize, rel_addr as usize)
}
}
impl PPUMemory for PPUBus {
fn readb_ppu(&self, addr: Addr) -> Byte {
// Palette is never mapped to cartridge
if PALETTE_ADDR_RANGE[0] <= addr && addr <= PALETTE_ADDR_RANGE[1] {
let mut rel_addr = addr - 0x3F00;
rel_addr = rel_addr % 0x0020;
if rel_addr == 0x0010 { rel_addr = 0x0000 }
if rel_addr == 0x0014 { rel_addr = 0x0004 }
if rel_addr == 0x0018 { rel_addr = 0x0008 }
if rel_addr == 0x001C { rel_addr = 0x000C }
return self.palette_memory[(rel_addr) as usize]
let idx = self.map_palette_addr(addr);
return self.palette_memory[idx]
}
// give the cartridge a chance to handle the rest
@@ -54,35 +84,22 @@ impl PPUMemory for PPUBus {
}
if PATTERN_ADDR_RANGE[0] <= addr && addr <= PATTERN_ADDR_RANGE[1] {
let table = if addr < 0x1000 { 0 } else { 1 };
return self.pattern_memory[table as usize][(addr % 0x1000) as usize]
let idx = self.map_pattern_table_addr(addr);
return self.pattern_memory[idx.0][idx.1]
}
if NAMETABLE_ADDR_RANGE[0] <= addr && addr <= NAMETABLE_ADDR_RANGE[1] {
let table = if addr < 0x2400 {
0
} else if addr < 0x2800 {
1
} else if addr < 0x2C00 {
2
} else {
3
};
let rel_addr = addr - 0x2000;
return self.nametable_memory[table][(rel_addr % 0x400) as usize]
let idx = &self.map_nametable_addr(addr);
return self.nametable_memory[idx.0][idx.1]
}
0x00
}
fn writeb_ppu(&mut self, addr: Addr, data: Byte) {
// Palette is never mapped to cartridge
if PALETTE_ADDR_RANGE[0] <= addr && addr <= PALETTE_ADDR_RANGE[1] {
let mut rel_addr = addr - 0x3F00;
rel_addr = rel_addr % 0x0020;
if rel_addr == 0x0010 { rel_addr = 0x0000 }
if rel_addr == 0x0014 { rel_addr = 0x0004 }
if rel_addr == 0x0018 { rel_addr = 0x0008 }
if rel_addr == 0x001C { rel_addr = 0x000C }
self.palette_memory[(rel_addr % 0x0020) as usize] = data;
let idx = self.map_palette_addr(addr);
self.palette_memory[idx] = data;
}
// give the cartridge a chance to handle the rest
@@ -93,21 +110,12 @@ impl PPUMemory for PPUBus {
}
if PATTERN_ADDR_RANGE[0] <= addr && addr <= PATTERN_ADDR_RANGE[1] {
let table = if addr < 0x1000 { 0 } else { 1 };
self.pattern_memory[table as usize][(addr % 0x1000) as usize] = data;
let idx = self.map_pattern_table_addr(addr);
self.pattern_memory[idx.0][idx.1] = data;
}
if NAMETABLE_ADDR_RANGE[0] <= addr && addr <= NAMETABLE_ADDR_RANGE[1] {
let table = if addr < 0x2400 {
0
} else if addr < 0x2800 {
1
} else if addr < 0x2C00 {
2
} else {
3
};
let rel_addr = addr - 0x2000;
self.nametable_memory[table][(rel_addr % 0x400) as usize] = data;
let idx = &self.map_nametable_addr(addr);
self.nametable_memory[idx.0][idx.1] = data;
}
}
}