yuzu/src/video_core/pica.h
Tony Wasserka 98ad16a45b Pica: Add float24 structure.
24-bit floating points are used internally for calculations on the GPU, however the current code will still emulate that with 32-bit floating points.
In the future we might want to accurately perform the calculations with correct bitness in the future, but for now we just wrap the calculations around this class.
2014-08-12 13:46:24 +02:00

252 lines
8.6 KiB
C++

// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.
#pragma once
#include <cstddef>
#include <initializer_list>
#include <map>
#include "common/bit_field.h"
#include "common/common_types.h"
namespace Pica {
// Returns index corresponding to the Regs member labeled by field_name
// TODO: Due to Visual studio bug 209229, offsetof does not return constant expressions
// when used with array elements (e.g. PICA_REG_INDEX(vs_uniform_setup.set_value[1])).
// For details cf. https://connect.microsoft.com/VisualStudio/feedback/details/209229/offsetof-does-not-produce-a-constant-expression-for-array-members
// Hopefully, this will be fixed sometime in the future.
// For lack of better alternatives, we currently hardcode the offsets when constant
// expressions are needed via PICA_REG_INDEX_WORKAROUND (on sane compilers, static_asserts
// will then make sure the offsets indeed match the automatically calculated ones).
#define PICA_REG_INDEX(field_name) (offsetof(Pica::Regs, field_name) / sizeof(u32))
#if defined(_MSC_VER)
#define PICA_REG_INDEX_WORKAROUND(field_name, backup_workaround_index) (backup_workaround_index)
#else
// NOTE: Yeah, hacking in a static_assert here just to workaround the lacking MSVC compiler
// really is this annoying. This macro just forwards its first argument to PICA_REG_INDEX
// and then performs a (no-op) cast to size_t iff the second argument matches the expected
// field offset. Otherwise, the compiler will fail to compile this code.
#define PICA_REG_INDEX_WORKAROUND(field_name, backup_workaround_index) \
((typename std::enable_if<backup_workaround_index == PICA_REG_INDEX(field_name), size_t>::type)PICA_REG_INDEX(field_name))
#endif // _MSC_VER
struct Regs {
// helper macro to properly align structure members.
// Calling INSERT_PADDING_WORDS will add a new member variable with a name like "pad121",
// depending on the current source line to make sure variable names are unique.
#define INSERT_PADDING_WORDS_HELPER1(x, y) x ## y
#define INSERT_PADDING_WORDS_HELPER2(x, y) INSERT_PADDING_WORDS_HELPER1(x, y)
#define INSERT_PADDING_WORDS(num_words) u32 INSERT_PADDING_WORDS_HELPER2(pad, __LINE__)[(num_words)];
INSERT_PADDING_WORDS(0x41);
BitField<0, 24, u32> viewport_size_x;
INSERT_PADDING_WORDS(0x1);
BitField<0, 24, u32> viewport_size_y;
INSERT_PADDING_WORDS(0x1bc);
union {
enum class Format : u64 {
BYTE = 0,
UBYTE = 1,
SHORT = 2,
FLOAT = 3,
};
BitField< 0, 2, Format> format0;
BitField< 2, 2, u64> size0; // number of elements minus 1
BitField< 4, 2, Format> format1;
BitField< 6, 2, u64> size1;
BitField< 8, 2, Format> format2;
BitField<10, 2, u64> size2;
BitField<12, 2, Format> format3;
BitField<14, 2, u64> size3;
BitField<16, 2, Format> format4;
BitField<18, 2, u64> size4;
BitField<20, 2, Format> format5;
BitField<22, 2, u64> size5;
BitField<24, 2, Format> format6;
BitField<26, 2, u64> size6;
BitField<28, 2, Format> format7;
BitField<30, 2, u64> size7;
BitField<32, 2, Format> format8;
BitField<34, 2, u64> size8;
BitField<36, 2, Format> format9;
BitField<38, 2, u64> size9;
BitField<40, 2, Format> format10;
BitField<42, 2, u64> size10;
BitField<44, 2, Format> format11;
BitField<46, 2, u64> size11;
BitField<48, 12, u64> attribute_mask;
BitField<60, 4, u64> num_attributes; // number of total attributes minus 1
} vertex_descriptor;
INSERT_PADDING_WORDS(0xfe);
#undef INSERT_PADDING_WORDS_HELPER1
#undef INSERT_PADDING_WORDS_HELPER2
#undef INSERT_PADDING_WORDS
// Map register indices to names readable by humans
// Used for debugging purposes, so performance is not an issue here
static std::string GetCommandName(int index) {
std::map<u32, std::string> map;
Regs regs;
// TODO: MSVC does not support using offsetof() on non-static data members even though this
// is technically allowed since C++11. Hence, this functionality is disabled until
// MSVC properly supports it.
#ifndef _MSC_VER
#define ADD_FIELD(name) \
do { \
map.insert({PICA_REG_INDEX(name), #name}); \
for (u32 i = PICA_REG_INDEX(name) + 1; i < PICA_REG_INDEX(name) + sizeof(regs.name) / 4; ++i) \
map.insert({i, #name + std::string("+") + std::to_string(i-PICA_REG_INDEX(name))}); \
} while(false)
ADD_FIELD(viewport_size_x);
ADD_FIELD(viewport_size_y);
ADD_FIELD(vertex_descriptor);
#undef ADD_FIELD
#endif // _MSC_VER
// Return empty string if no match is found
return map[index];
}
static inline int NumIds() {
return sizeof(Regs) / sizeof(u32);
}
u32& operator [] (int index) const {
u32* content = (u32*)this;
return content[index];
}
u32& operator [] (int index) {
u32* content = (u32*)this;
return content[index];
}
private:
/*
* Most physical addresses which Pica registers refer to are 8-byte aligned.
* This function should be used to get the address from a raw register value.
*/
static inline u32 DecodeAddressRegister(u32 register_value) {
return register_value * 8;
}
};
// TODO: MSVC does not support using offsetof() on non-static data members even though this
// is technically allowed since C++11. This macro should be enabled once MSVC adds
// support for that.
#ifndef _MSC_VER
#define ASSERT_REG_POSITION(field_name, position) static_assert(offsetof(Regs, field_name) == position * 4, "Field "#field_name" has invalid position")
ASSERT_REG_POSITION(viewport_size_x, 0x41);
ASSERT_REG_POSITION(viewport_size_y, 0x43);
ASSERT_REG_POSITION(vertex_descriptor, 0x200);
#undef ASSERT_REG_POSITION
#endif // !defined(_MSC_VER)
// The total number of registers is chosen arbitrarily, but let's make sure it's not some odd value anyway.
static_assert(sizeof(Regs) == 0x300 * sizeof(u32), "Invalid total size of register set");
struct float24 {
static float24 FromFloat32(float val) {
float24 ret;
ret.value = val;
return ret;
}
// 16 bit mantissa, 7 bit exponent, 1 bit sign
// TODO: No idea if this works as intended
static float24 FromRawFloat24(u32 hex) {
float24 ret;
if ((hex & 0xFFFFFF) == 0) {
ret.value = 0;
} else {
u32 mantissa = hex & 0xFFFF;
u32 exponent = (hex >> 16) & 0x7F;
u32 sign = hex >> 23;
ret.value = powf(2.0f, (float)exponent-63.0f) * (1.0f + mantissa * powf(2.0f, -16.f));
if (sign)
ret.value = -ret.value;
}
return ret;
}
// Not recommended for anything but logging
float ToFloat32() const {
return value;
}
float24 operator * (const float24& flt) const {
return float24::FromFloat32(ToFloat32() * flt.ToFloat32());
}
float24 operator / (const float24& flt) const {
return float24::FromFloat32(ToFloat32() / flt.ToFloat32());
}
float24 operator + (const float24& flt) const {
return float24::FromFloat32(ToFloat32() + flt.ToFloat32());
}
float24 operator - (const float24& flt) const {
return float24::FromFloat32(ToFloat32() - flt.ToFloat32());
}
float24 operator - () const {
return float24::FromFloat32(-ToFloat32());
}
bool operator < (const float24& flt) const {
return ToFloat32() < flt.ToFloat32();
}
bool operator > (const float24& flt) const {
return ToFloat32() > flt.ToFloat32();
}
bool operator >= (const float24& flt) const {
return ToFloat32() >= flt.ToFloat32();
}
bool operator <= (const float24& flt) const {
return ToFloat32() <= flt.ToFloat32();
}
private:
float24() = default;
// Stored as a regular float, merely for convenience
// TODO: Perform proper arithmetic on this!
float value;
};
union CommandHeader {
CommandHeader(u32 h) : hex(h) {}
u32 hex;
BitField< 0, 16, u32> cmd_id;
BitField<16, 4, u32> parameter_mask;
BitField<20, 11, u32> extra_data_length;
BitField<31, 1, u32> group_commands;
};
} // namespace