citra/src/video_core/shader/shader.h
2015-08-15 18:03:27 -04:00

170 lines
5.6 KiB
C++

// Copyright 2015 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <boost/container/static_vector.hpp>
#include <nihstro/shader_binary.h>
#include "common/common_funcs.h"
#include "common/common_types.h"
#include "common/vector_math.h"
#include "video_core/pica.h"
using nihstro::RegisterType;
using nihstro::SourceRegister;
using nihstro::DestRegister;
namespace Pica {
namespace Shader {
struct InputVertex {
Math::Vec4<float24> attr[16];
};
struct OutputVertex {
OutputVertex() = default;
// VS output attributes
Math::Vec4<float24> pos;
Math::Vec4<float24> dummy; // quaternions (not implemented, yet)
Math::Vec4<float24> color;
Math::Vec2<float24> tc0;
Math::Vec2<float24> tc1;
float24 pad[6];
Math::Vec2<float24> tc2;
// Padding for optimal alignment
float24 pad2[4];
// Attributes used to store intermediate results
// position after perspective divide
Math::Vec3<float24> screenpos;
float24 pad3;
// Linear interpolation
// factor: 0=this, 1=vtx
void Lerp(float24 factor, const OutputVertex& vtx) {
pos = pos * factor + vtx.pos * (float24::FromFloat32(1) - factor);
// TODO: Should perform perspective correct interpolation here...
tc0 = tc0 * factor + vtx.tc0 * (float24::FromFloat32(1) - factor);
tc1 = tc1 * factor + vtx.tc1 * (float24::FromFloat32(1) - factor);
tc2 = tc2 * factor + vtx.tc2 * (float24::FromFloat32(1) - factor);
screenpos = screenpos * factor + vtx.screenpos * (float24::FromFloat32(1) - factor);
color = color * factor + vtx.color * (float24::FromFloat32(1) - factor);
}
// Linear interpolation
// factor: 0=v0, 1=v1
static OutputVertex Lerp(float24 factor, const OutputVertex& v0, const OutputVertex& v1) {
OutputVertex ret = v0;
ret.Lerp(factor, v1);
return ret;
}
};
static_assert(std::is_pod<OutputVertex>::value, "Structure is not POD");
static_assert(sizeof(OutputVertex) == 32 * sizeof(float), "OutputVertex has invalid size");
/**
* This structure contains the state information that needs to be unique for a shader unit. The 3DS
* has four shader units that process shaders in parallel. At the present, Citra only implements a
* single shader unit that processes all shaders serially. Putting the state information in a struct
* here will make it easier for us to parallelize the shader processing later.
*/
struct UnitState {
struct Registers {
// The registers are accessed by the shader JIT using SSE instructions, and are therefore
// required to be 16-byte aligned.
Math::Vec4<float24> MEMORY_ALIGNED16(input[16]);
Math::Vec4<float24> MEMORY_ALIGNED16(output[16]);
Math::Vec4<float24> MEMORY_ALIGNED16(temporary[16]);
} registers;
static_assert(std::is_pod<Registers>::value, "Structure is not POD");
u32 program_counter;
bool conditional_code[2];
// Two Address registers and one loop counter
// TODO: How many bits do these actually have?
s32 address_registers[3];
enum {
INVALID_ADDRESS = 0xFFFFFFFF
};
struct CallStackElement {
u32 final_address; // Address upon which we jump to return_address
u32 return_address; // Where to jump when leaving scope
u8 repeat_counter; // How often to repeat until this call stack element is removed
u8 loop_increment; // Which value to add to the loop counter after an iteration
// TODO: Should this be a signed value? Does it even matter?
u32 loop_address; // The address where we'll return to after each loop iteration
};
// TODO: Is there a maximal size for this?
boost::container::static_vector<CallStackElement, 16> call_stack;
struct {
u32 max_offset; // maximum program counter ever reached
u32 max_opdesc_id; // maximum swizzle pattern index ever used
} debug;
static int InputOffset(const SourceRegister& reg) {
switch (reg.GetRegisterType()) {
case RegisterType::Input:
return (int)offsetof(UnitState::Registers, input) + reg.GetIndex()*sizeof(Math::Vec4<float24>);
case RegisterType::Temporary:
return (int)offsetof(UnitState::Registers, temporary) + reg.GetIndex()*sizeof(Math::Vec4<float24>);
default:
UNREACHABLE();
return 0;
}
}
static int OutputOffset(const DestRegister& reg) {
switch (reg.GetRegisterType()) {
case RegisterType::Output:
return (int)offsetof(UnitState::Registers, output) + reg.GetIndex()*sizeof(Math::Vec4<float24>);
case RegisterType::Temporary:
return (int)offsetof(UnitState::Registers, temporary) + reg.GetIndex()*sizeof(Math::Vec4<float24>);
default:
UNREACHABLE();
return 0;
}
}
};
/**
* Performs any shader unit setup that only needs to happen once per shader (as opposed to once per
* vertex, which would happen within the `Run` function).
* @param state Shader unit state, must be setup per shader and per shader unit
*/
void Setup(UnitState& state);
/// Performs any cleanup when the emulator is shutdown
void Shutdown();
/**
* Runs the currently setup shader
* @param state Shader unit state, must be setup per shader and per shader unit
* @param input Input vertex into the shader
* @param num_attributes The number of vertex shader attributes
* @return The output vertex, after having been processed by the vertex shader
*/
OutputVertex Run(UnitState& state, const InputVertex& input, int num_attributes);
} // namespace Shader
} // namespace Pica