libretro-dolphin/Source/Core/VideoCommon/IndexGenerator.cpp
Lioncash 10f7674651 VideoCommon/IndexGenerator: Eliminate static state
Now that we've extracted all of the stateless functions that can be
hidden, it's time to make the index generator a regular class with
active data members.

This can just be a member that sits within the vertex manager base
class. By deglobalizing the state of the index generator we also get rid
of the wonky dual-initializing that was going on within the OpenGL
backend.

Since the renderer is always initialized before the vertex manager, we
now only call Init() once throughout the execution lifecycle.
2019-12-05 10:49:32 -05:00

255 lines
6.1 KiB
C++

// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#include "VideoCommon/IndexGenerator.h"
#include <array>
#include <cstddef>
#include <cstring>
#include "Common/CommonTypes.h"
#include "Common/Logging/Log.h"
#include "VideoCommon/OpcodeDecoding.h"
#include "VideoCommon/VideoConfig.h"
namespace
{
constexpr u16 s_primitive_restart = UINT16_MAX;
template <bool pr>
u16* WriteTriangle(u16* index_ptr, u32 index1, u32 index2, u32 index3)
{
*index_ptr++ = index1;
*index_ptr++ = index2;
*index_ptr++ = index3;
if constexpr (pr)
*index_ptr++ = s_primitive_restart;
return index_ptr;
}
template <bool pr>
u16* AddList(u16* index_ptr, u32 num_verts, u32 index)
{
for (u32 i = 2; i < num_verts; i += 3)
{
index_ptr = WriteTriangle<pr>(index_ptr, index + i - 2, index + i - 1, index + i);
}
return index_ptr;
}
template <bool pr>
u16* AddStrip(u16* index_ptr, u32 num_verts, u32 index)
{
if constexpr (pr)
{
for (u32 i = 0; i < num_verts; ++i)
{
*index_ptr++ = index + i;
}
*index_ptr++ = s_primitive_restart;
}
else
{
bool wind = false;
for (u32 i = 2; i < num_verts; ++i)
{
index_ptr = WriteTriangle<pr>(index_ptr, index + i - 2, index + i - !wind, index + i - wind);
wind ^= true;
}
}
return index_ptr;
}
/**
* FAN simulator:
*
* 2---3
* / \ / \
* 1---0---4
*
* would generate this triangles:
* 012, 023, 034
*
* rotated (for better striping):
* 120, 302, 034
*
* as odd ones have to winded, following strip is fine:
* 12034
*
* so we use 6 indices for 3 triangles
*/
template <bool pr>
u16* AddFan(u16* index_ptr, u32 num_verts, u32 index)
{
u32 i = 2;
if constexpr (pr)
{
for (; i + 3 <= num_verts; i += 3)
{
*index_ptr++ = index + i - 1;
*index_ptr++ = index + i + 0;
*index_ptr++ = index;
*index_ptr++ = index + i + 1;
*index_ptr++ = index + i + 2;
*index_ptr++ = s_primitive_restart;
}
for (; i + 2 <= num_verts; i += 2)
{
*index_ptr++ = index + i - 1;
*index_ptr++ = index + i + 0;
*index_ptr++ = index;
*index_ptr++ = index + i + 1;
*index_ptr++ = s_primitive_restart;
}
}
for (; i < num_verts; ++i)
{
index_ptr = WriteTriangle<pr>(index_ptr, index, index + i - 1, index + i);
}
return index_ptr;
}
/*
* QUAD simulator
*
* 0---1 4---5
* |\ | |\ |
* | \ | | \ |
* | \| | \|
* 3---2 7---6
*
* 012,023, 456,467 ...
* or 120,302, 564,746
* or as strip: 1203, 5647
*
* Warning:
* A simple triangle has to be rendered for three vertices.
* ZWW do this for sun rays
*/
template <bool pr>
u16* AddQuads(u16* index_ptr, u32 num_verts, u32 index)
{
u32 i = 3;
for (; i < num_verts; i += 4)
{
if constexpr (pr)
{
*index_ptr++ = index + i - 2;
*index_ptr++ = index + i - 1;
*index_ptr++ = index + i - 3;
*index_ptr++ = index + i - 0;
*index_ptr++ = s_primitive_restart;
}
else
{
index_ptr = WriteTriangle<pr>(index_ptr, index + i - 3, index + i - 2, index + i - 1);
index_ptr = WriteTriangle<pr>(index_ptr, index + i - 3, index + i - 1, index + i - 0);
}
}
// three vertices remaining, so render a triangle
if (i == num_verts)
{
index_ptr = WriteTriangle<pr>(index_ptr, index + num_verts - 3, index + num_verts - 2,
index + num_verts - 1);
}
return index_ptr;
}
template <bool pr>
u16* AddQuads_nonstandard(u16* index_ptr, u32 num_verts, u32 index)
{
WARN_LOG(VIDEO, "Non-standard primitive drawing command GL_DRAW_QUADS_2");
return AddQuads<pr>(index_ptr, num_verts, index);
}
u16* AddLineList(u16* index_ptr, u32 num_verts, u32 index)
{
for (u32 i = 1; i < num_verts; i += 2)
{
*index_ptr++ = index + i - 1;
*index_ptr++ = index + i;
}
return index_ptr;
}
// Shouldn't be used as strips as LineLists are much more common
// so converting them to lists
u16* AddLineStrip(u16* index_ptr, u32 num_verts, u32 index)
{
for (u32 i = 1; i < num_verts; ++i)
{
*index_ptr++ = index + i - 1;
*index_ptr++ = index + i;
}
return index_ptr;
}
u16* AddPoints(u16* index_ptr, u32 num_verts, u32 index)
{
for (u32 i = 0; i != num_verts; ++i)
{
*index_ptr++ = index + i;
}
return index_ptr;
}
} // Anonymous namespace
void IndexGenerator::Init()
{
if (g_Config.backend_info.bSupportsPrimitiveRestart)
{
m_primitive_table[OpcodeDecoder::GX_DRAW_QUADS] = AddQuads<true>;
m_primitive_table[OpcodeDecoder::GX_DRAW_QUADS_2] = AddQuads_nonstandard<true>;
m_primitive_table[OpcodeDecoder::GX_DRAW_TRIANGLES] = AddList<true>;
m_primitive_table[OpcodeDecoder::GX_DRAW_TRIANGLE_STRIP] = AddStrip<true>;
m_primitive_table[OpcodeDecoder::GX_DRAW_TRIANGLE_FAN] = AddFan<true>;
}
else
{
m_primitive_table[OpcodeDecoder::GX_DRAW_QUADS] = AddQuads<false>;
m_primitive_table[OpcodeDecoder::GX_DRAW_QUADS_2] = AddQuads_nonstandard<false>;
m_primitive_table[OpcodeDecoder::GX_DRAW_TRIANGLES] = AddList<false>;
m_primitive_table[OpcodeDecoder::GX_DRAW_TRIANGLE_STRIP] = AddStrip<false>;
m_primitive_table[OpcodeDecoder::GX_DRAW_TRIANGLE_FAN] = AddFan<false>;
}
m_primitive_table[OpcodeDecoder::GX_DRAW_LINES] = AddLineList;
m_primitive_table[OpcodeDecoder::GX_DRAW_LINE_STRIP] = AddLineStrip;
m_primitive_table[OpcodeDecoder::GX_DRAW_POINTS] = AddPoints;
}
void IndexGenerator::Start(u16* index_ptr)
{
m_index_buffer_current = index_ptr;
m_base_index_ptr = index_ptr;
m_base_index = 0;
}
void IndexGenerator::AddIndices(int primitive, u32 num_vertices)
{
m_index_buffer_current =
m_primitive_table[primitive](m_index_buffer_current, num_vertices, m_base_index);
m_base_index += num_vertices;
}
void IndexGenerator::AddExternalIndices(const u16* indices, u32 num_indices, u32 num_vertices)
{
std::memcpy(m_index_buffer_current, indices, sizeof(u16) * num_indices);
m_index_buffer_current += num_indices;
m_base_index += num_vertices;
}
u32 IndexGenerator::GetRemainingIndices() const
{
// -1 is reserved for primitive restart (OGL + DX11)
constexpr u32 max_index = 65534;
return max_index - m_base_index;
}