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mirror of https://github.com/lefticus/6502-cpp.git synced 2024-12-30 07:31:38 +00:00

Initialize the sprite data at compilation time, not at runtime.

VIC_II::SPRITE_ALIGNMENT: The MOS 6566/6567/6569 VIC-II expects
sprite data to be aligned at 64 bytes.

VIC_II::SPRITE_STARTING_BANK: Remove.

VIC_II::write_multi_color_pixel(), VIC_II::write_pixel(): Make static.
Write to the specified memory address.

VIC_II::Sprite::Sprite(): Refactored from VIC_II::make_sprite().

VIC_II::enable_sprite(): Take a Sprite reference.

sBall, sBat: Sprite images, declared at global scope.

FIXME: How to ensure that the VIC_II::Sprite addresses do not end up in
the range 0x1000..0x1fff or 0x9000..0x9fff (where the character generator
ROM is overriding RAM)? Any portable alternative to using GCC-style
__attribute__((section("sprites"))) and a linker script?

Note: Declaring the sprite images as static const objects in main()
would cause clang++4.0-svn279916-1 to generate code for initializing them.
So, we will declare the objects in the global scope.

This has been tested on a Commodore 64 with the following steps:

clang++-4.0 -m32 -O3 -std=c++1z -S pong.cpp
x86-to-6502 < pong.s > pong.asm
edit pong.asm to define code start at 0x900 and to adapt the output
invoke some 6502 assembler
SYS2304 to run the output on a Commodore 64
This commit is contained in:
Marko Mäkelä 2016-10-06 17:46:33 +03:00
parent 4ed4e6a94c
commit 504d13a527

View File

@ -121,10 +121,10 @@ namespace {
struct VIC_II
{
static constexpr uint8_t SPRITE_ALIGNMENT = 64;
static constexpr uint16_t SPRITE_DATA_POINTERS = 2040;
static constexpr uint16_t VIDEO_REGISTERS = 53248;
static constexpr uint16_t VIDEO_MEMORY = 1024;
static constexpr uint8_t SPRITE_STARTING_BANK = 192;
static constexpr uint16_t BORDER_COLOR = 53280;
static constexpr uint16_t BACKGROUND_COLOR = 53281;
static constexpr uint16_t SPRITE_POSITION_REGISTERS = VIDEO_REGISTERS;
@ -191,52 +191,63 @@ namespace {
return Frame(*this, p1, p2);
}
void write_multi_color_pixel(uint16_t)
static void write_multi_color_pixel(uint8_t*)
{
// 0th case
}
void write_pixel(uint16_t)
static void write_pixel(uint8_t*)
{
// 0th case
}
template<typename ... D >
void write_multi_color_pixel(uint16_t loc, uint8_t d1, uint8_t d2,
uint8_t d3, uint8_t d4, D ... d)
static void write_multi_color_pixel(uint8_t* mem, uint8_t d1, uint8_t d2,
uint8_t d3, uint8_t d4, D ... d)
{
memory(loc) = (d1 << 6) | (d2 << 4) | (d3 << 2) | d4;
write_multi_color_pixel(loc + 1, d...);
*mem = (d1 << 6) | (d2 << 4) | (d3 << 2) | d4;
write_multi_color_pixel(mem + 1, d...);
}
template<typename ... D >
void write_pixel(uint16_t loc, bool d1, bool d2, bool d3, bool d4,
bool d5, bool d6, bool d7, bool d8, D ... d)
static void write_pixel(uint8_t *mem, bool d1, bool d2, bool d3, bool d4,
bool d5, bool d6, bool d7, bool d8, D ... d)
{
memory(loc) = (d1 << 7) | (d2 << 6) | (d3 << 5) | (d4 << 4) | (d5 << 3) | (d6 << 2) | (d7 << 1) | d8;
write_pixel(loc + 1, d...);
*mem = (d1 << 7) | (d2 << 6) | (d3 << 5) | (d4 << 4) | (d5 << 3) | (d6 << 2) | (d7 << 1) | d8;
write_pixel(mem + 1, d...);
}
template<typename ... D>
void make_sprite(uint8_t memory_loc, D ... d)
{
if constexpr(sizeof...(d) == 12 * 21) {
write_multi_color_pixel((SPRITE_STARTING_BANK + memory_loc) * 64, d...);
} else {
write_pixel((SPRITE_STARTING_BANK + memory_loc) * 64, d...);
struct Sprite {
alignas(SPRITE_ALIGNMENT) uint8_t memory[63];
template<typename ... D>
Sprite(D ... d)
{
if constexpr(sizeof...(d) == 12 * 21) {
write_multi_color_pixel(memory, d...);
} else {
write_pixel(memory, d...);
}
}
}
};
///
/// New Code
///
void enable_sprite(const uint8_t sprite_number, const uint8_t memory_loc,
void enable_sprite(const uint8_t sprite_number, const Sprite& bitmap,
const bool multicolor, const bool low_priority,
const bool double_width, const bool double_height)
{
memory(SPRITE_DATA_POINTERS + sprite_number)
= SPRITE_STARTING_BANK + memory_loc;
#if 0 // error: static_assert expression is not an integral constant
static_assert((std::ptrdiff_t(bitmap.memory) & 0x7000) != 0x1000,
"The addresses 0x1000 to 0x1fff and 0x9000 to 0x9fff"
"point to the character generator ROM, not RAM.");
static_assert(std::ptrdiff_t(bitmap.memory) < 0x4000,
"The data must be within the first (default)"
" 16KiB VIC-II bank.");
#endif
memory(SPRITE_DATA_POINTERS + sprite_number)
= (std::ptrdiff_t(bitmap.memory) & 0x3fff) / SPRITE_ALIGNMENT;
set_bit(SPRITE_ENABLE_BITS, sprite_number, true);
set_bit(SPRITE_EXPAND_HORIZONTAL, sprite_number, double_width);
set_bit(SPRITE_EXPAND_VERTICAL, sprite_number, double_height);
@ -280,8 +291,56 @@ namespace {
}
/// The ball image. This has to be declared const in the global scope,
/// or otherwise the data will not be initialized at compilation time.
const VIC_II::Sprite sBall(
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,
0,0,0,0,0,0,1,1,0,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,
0,0,0,0,0,1,1,0,0,0,1,1,1,1,1,1,1,1,1,0,0,0,0,0,
0,0,0,0,0,1,1,1,0,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,
0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,
0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,
0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,
0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,
0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,
0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,
0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,
0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,
0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,
0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
);
/// The bat image.
const VIC_II::Sprite sBat(
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,3,3,0,0,0,0,0,
0,0,0,0,0,1,1,0,0,0,0,0,
0,0,0,0,0,3,3,0,0,0,0,0,
0,0,0,0,0,1,1,0,0,0,0,0,
0,0,0,0,0,3,3,0,0,0,0,0
);
int main()
{
@ -306,58 +365,9 @@ int main()
VIC_II vic;
vic.make_sprite(0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,
0,0,0,0,0,0,1,1,0,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,
0,0,0,0,0,1,1,0,0,0,1,1,1,1,1,1,1,1,1,0,0,0,0,0,
0,0,0,0,0,1,1,1,0,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,
0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,
0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,
0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,
0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,
0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,
0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,
0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,
0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,
0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,
0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
);
vic.make_sprite(1,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,2,2,0,0,0,0,0,
0,0,0,0,0,3,3,0,0,0,0,0,
0,0,0,0,0,1,1,0,0,0,0,0,
0,0,0,0,0,3,3,0,0,0,0,0,
0,0,0,0,0,1,1,0,0,0,0,0,
0,0,0,0,0,3,3,0,0,0,0,0
);
vic.enable_sprite(0, 0, false, true, false, false);
vic.enable_sprite(1, 1, true, false, false, true);
vic.enable_sprite(2, 1, true, false, false, true);
vic.enable_sprite(0, sBall, false, true, false, false);
vic.enable_sprite(1, sBat, true, false, false, true);
vic.enable_sprite(2, sBat, true, false, false, true);
vic.border() = vic.nearest_color<128,128,128>(colors).num; // 50% grey
vic.background() = vic.nearest_color<0,0,0>(colors).num; // black
vic.sprite_1_color() = vic.nearest_color<255,0,0>(colors).num; // red