// Copyright 2008 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#include "VideoCommon/VertexShaderGen.h"
#include "Common/Assert.h"
#include "Common/CommonTypes.h"
#include "VideoCommon/BPMemory.h"
#include "VideoCommon/ConstantManager.h"
#include "VideoCommon/LightingShaderGen.h"
#include "VideoCommon/NativeVertexFormat.h"
#include "VideoCommon/VertexLoaderManager.h"
#include "VideoCommon/VideoCommon.h"
#include "VideoCommon/VideoConfig.h"
#include "VideoCommon/XFMemory.h"
VertexShaderUid GetVertexShaderUid()
{
ASSERT(bpmem.genMode.numtexgens == xfmem.numTexGen.numTexGens);
ASSERT(bpmem.genMode.numcolchans == xfmem.numChan.numColorChans);
VertexShaderUid out;
vertex_shader_uid_data* const uid_data = out.GetUidData();
uid_data->numTexGens = xfmem.numTexGen.numTexGens;
uid_data->components = VertexLoaderManager::g_current_components;
uid_data->numColorChans = xfmem.numChan.numColorChans;
GetLightingShaderUid(uid_data->lighting);
// transform texcoords
for (u32 i = 0; i < uid_data->numTexGens; ++i)
{
auto& texinfo = uid_data->texMtxInfo[i];
texinfo.sourcerow = xfmem.texMtxInfo[i].sourcerow;
texinfo.texgentype = xfmem.texMtxInfo[i].texgentype;
texinfo.inputform = xfmem.texMtxInfo[i].inputform;
// first transformation
switch (texinfo.texgentype)
{
case TexGenType::EmbossMap: // calculate tex coords into bump map
if ((uid_data->components & (VB_HAS_TANGENT | VB_HAS_BINORMAL)) != 0)
{
// transform the light dir into tangent space
texinfo.embosslightshift = xfmem.texMtxInfo[i].embosslightshift;
texinfo.embosssourceshift = xfmem.texMtxInfo[i].embosssourceshift;
}
else
{
texinfo.embosssourceshift = xfmem.texMtxInfo[i].embosssourceshift;
}
break;
case TexGenType::Color0:
case TexGenType::Color1:
break;
case TexGenType::Regular:
default:
uid_data->texMtxInfo_n_projection |= static_cast<u32>(xfmem.texMtxInfo[i].projection.Value())
<< i;
break;
}
uid_data->dualTexTrans_enabled = xfmem.dualTexTrans.enabled;
// CHECKME: does this only work for regular tex gen types?
if (uid_data->dualTexTrans_enabled && texinfo.texgentype == TexGenType::Regular)
{
auto& postInfo = uid_data->postMtxInfo[i];
postInfo.index = xfmem.postMtxInfo[i].index;
postInfo.normalize = xfmem.postMtxInfo[i].normalize;
}
}
return out;
}
ShaderCode GenerateVertexShaderCode(APIType api_type, const ShaderHostConfig& host_config,
const vertex_shader_uid_data* uid_data)
{
ShaderCode out;
const bool per_pixel_lighting = g_ActiveConfig.bEnablePixelLighting;
const bool msaa = host_config.msaa;
const bool ssaa = host_config.ssaa;
const bool vertex_rounding = host_config.vertex_rounding;
ShaderCode input_extract;
out.Write("{}", s_lighting_struct);
// uniforms
out.Write("UBO_BINDING(std140, 2) uniform VSBlock {{\n");
out.Write("{}", s_shader_uniforms);
out.Write("}};\n");
if (uid_data->vs_expand != VSExpand::None)
{
out.Write("UBO_BINDING(std140, 3) uniform GSBlock {{\n");
out.Write("{}", s_geometry_shader_uniforms);
out.Write("}};\n");
if (api_type == APIType::D3D)
{
// D3D doesn't include the base vertex in SV_VertexID
out.Write("UBO_BINDING(std140, 4) uniform DX_Constants {{\n"
" uint base_vertex;\n"
"}};\n\n");
}
}
out.Write("struct VS_OUTPUT {{\n");
GenerateVSOutputMembers(out, api_type, uid_data->numTexGens, host_config, "",
ShaderStage::Vertex);
out.Write("}};\n\n");
WriteIsNanHeader(out, api_type);
if (uid_data->vs_expand == VSExpand::None)
{
out.Write("ATTRIBUTE_LOCATION({:s}) in float4 rawpos;\n", ShaderAttrib::Position);
if ((uid_data->components & VB_HAS_POSMTXIDX) != 0)
out.Write("ATTRIBUTE_LOCATION({:s}) in uint4 posmtx;\n", ShaderAttrib::PositionMatrix);
if ((uid_data->components & VB_HAS_NORMAL) != 0)
out.Write("ATTRIBUTE_LOCATION({:s}) in float3 rawnormal;\n", ShaderAttrib::Normal);
if ((uid_data->components & VB_HAS_TANGENT) != 0)
out.Write("ATTRIBUTE_LOCATION({:s}) in float3 rawtangent;\n", ShaderAttrib::Tangent);
if ((uid_data->components & VB_HAS_BINORMAL) != 0)
out.Write("ATTRIBUTE_LOCATION({:s}) in float3 rawbinormal;\n", ShaderAttrib::Binormal);
if ((uid_data->components & VB_HAS_COL0) != 0)
out.Write("ATTRIBUTE_LOCATION({:s}) in float4 rawcolor0;\n", ShaderAttrib::Color0);
if ((uid_data->components & VB_HAS_COL1) != 0)
out.Write("ATTRIBUTE_LOCATION({:s}) in float4 rawcolor1;\n", ShaderAttrib::Color1);
for (u32 i = 0; i < 8; ++i)
{
const u32 has_texmtx = (uid_data->components & (VB_HAS_TEXMTXIDX0 << i));
if ((uid_data->components & (VB_HAS_UV0 << i)) != 0 || has_texmtx != 0)
{
out.Write("ATTRIBUTE_LOCATION({:s}) in float{} rawtex{};\n", ShaderAttrib::TexCoord0 + i,
has_texmtx != 0 ? 3 : 2, i);
}
}
}
else
{
// Can't use float3, etc because we want 4-byte alignment
out.Write(
"uint4 unpack_ubyte4(uint value) {{\n"
" return uint4(value & 0xff, (value >> 8) & 0xff, (value >> 16) & 0xff, value >> 24);\n"
"}}\n\n"
"struct InputData {{\n");
if (uid_data->components & VB_HAS_POSMTXIDX)
{
out.Write(" uint posmtx;\n");
input_extract.Write("uint4 posmtx = unpack_ubyte4(i.posmtx);\n");
}
if (uid_data->position_has_3_elems)
{
out.Write(" float pos0;\n"
" float pos1;\n"
" float pos2;\n");
input_extract.Write("float4 rawpos = float4(i.pos0, i.pos1, i.pos2, 1.0f);\n");
}
else
{
out.Write(" float pos0;\n"
" float pos1;\n");
input_extract.Write("float4 rawpos = float4(i.pos0, i.pos1, 0.0f, 1.0f);\n");
}
std::array<std::string_view, 3> names = {"normal", "binormal", "tangent"};
for (int i = 0; i < 3; i++)
{
if (uid_data->components & (VB_HAS_NORMAL << i))
{
out.Write(" float {0}0;\n"
" float {0}1;\n"
" float {0}2;\n",
names[i]);
input_extract.Write("float3 raw{0} = float3(i.{0}0, i.{0}1, i.{0}2);\n", names[i]);
}
}
for (int i = 0; i < 2; i++)
{
if (uid_data->components & (VB_HAS_COL0 << i))
{
out.Write(" uint color{};\n", i);
input_extract.Write("float4 rawcolor{0} = float4(unpack_ubyte4(i.color{0})) / 255.0f;\n",
i);
}
}
for (int i = 0; i < 8; i++)
{
if (uid_data->components & (VB_HAS_UV0 << i))
{
u32 ncomponents = (uid_data->texcoord_elem_count >> (2 * i)) & 3;
if (ncomponents < 2)
{
out.Write(" float tex{};\n", i);
input_extract.Write("float3 rawtex{0} = float3(i.tex{0}, 0.0f, 0.0f);\n", i);
}
else if (ncomponents == 2)
{
out.Write(" float tex{0}_0;\n"
" float tex{0}_1;\n",
i);
input_extract.Write("float3 rawtex{0} = float3(i.tex{0}_0, i.tex{0}_1, 0.0f);\n", i);
}
else
{
out.Write(" float tex{0}_0;\n"
" float tex{0}_1;\n"
" float tex{0}_2;\n",
i);
input_extract.Write("float3 rawtex{0} = float3(i.tex{0}_0, i.tex{0}_1, i.tex{0}_2);\n",
i);
}
}
}
out.Write("}};\n\n"
"SSBO_BINDING(1) readonly restrict buffer InputBuffer {{\n"
" InputData input_buffer[];\n"
"}};\n\n");
}
if (host_config.backend_geometry_shaders)
{
out.Write("VARYING_LOCATION(0) out VertexData {{\n");
GenerateVSOutputMembers(out, api_type, uid_data->numTexGens, host_config,
GetInterpolationQualifier(msaa, ssaa, true, false),
ShaderStage::Vertex);
out.Write("}} vs;\n");
}
else
{
// Let's set up attributes
u32 counter = 0;
out.Write("VARYING_LOCATION({}) {} out float4 colors_0;\n", counter++,
GetInterpolationQualifier(msaa, ssaa));
out.Write("VARYING_LOCATION({}) {} out float4 colors_1;\n", counter++,
GetInterpolationQualifier(msaa, ssaa));
for (u32 i = 0; i < uid_data->numTexGens; ++i)
{
out.Write("VARYING_LOCATION({}) {} out float3 tex{};\n", counter++,
GetInterpolationQualifier(msaa, ssaa), i);
}
if (!host_config.fast_depth_calc)
{
out.Write("VARYING_LOCATION({}) {} out float4 clipPos;\n", counter++,
GetInterpolationQualifier(msaa, ssaa));
}
if (per_pixel_lighting)
{
out.Write("VARYING_LOCATION({}) {} out float3 Normal;\n", counter++,
GetInterpolationQualifier(msaa, ssaa));
out.Write("VARYING_LOCATION({}) {} out float3 WorldPos;\n", counter++,
GetInterpolationQualifier(msaa, ssaa));
}
}
out.Write("void main()\n{{\n");
if (uid_data->vs_expand != VSExpand::None)
{
out.Write("bool is_bottom = (gl_VertexID & 2) != 0;\n"
"bool is_right = (gl_VertexID & 1) != 0;\n");
// D3D doesn't include the base vertex in SV_VertexID
// See comment in UberShaderVertex for details
if (api_type == APIType::D3D)
out.Write("uint vertex_id = (gl_VertexID >> 2) + base_vertex;\n");
else
out.Write("uint vertex_id = gl_VertexID >> 2;\n");
out.Write("InputData i = input_buffer[vertex_id];\n"
"{}",
input_extract.GetBuffer());
}
out.Write("VS_OUTPUT o;\n");
// xfmem.numColorChans controls the number of color channels available to TEV, but we still need
// to generate all channels here, as it can be used in texgen. Cel-damage is an example of this.
out.Write("float4 vertex_color_0, vertex_color_1;\n");
// To use color 1, the vertex descriptor must have color 0 and 1.
// If color 1 is present but not color 0, it is used for lighting channel 0.
const bool use_color_1 =
(uid_data->components & (VB_HAS_COL0 | VB_HAS_COL1)) == (VB_HAS_COL0 | VB_HAS_COL1);
for (u32 color = 0; color < NUM_XF_COLOR_CHANNELS; color++)
{
if ((color == 0 || use_color_1) && (uid_data->components & (VB_HAS_COL0 << color)) != 0)
{
// Use color0 for channel 0, and color1 for channel 1 if both colors 0 and 1 are present.
out.Write("vertex_color_{0} = rawcolor{0};\n", color);
}
else if (color == 0 && (uid_data->components & VB_HAS_COL1) != 0)
{
// Use color1 for channel 0 if color0 is not present.
out.Write("vertex_color_{} = rawcolor1;\n", color);
}
else
{
out.Write("vertex_color_{0} = missing_color_value;\n", color);
}
}
// transforms
if ((uid_data->components & VB_HAS_POSMTXIDX) != 0)
{
// Vertex format has a per-vertex matrix
out.Write("int posidx = int(posmtx.r);\n"
"float4 P0 = " I_TRANSFORMMATRICES "[posidx];\n"
"float4 P1 = " I_TRANSFORMMATRICES "[posidx + 1];\n"
"float4 P2 = " I_TRANSFORMMATRICES "[posidx + 2];\n");
if ((uid_data->components & VB_HAS_NORMAL) != 0)
{
out.Write("int normidx = posidx & 31;\n"
"float3 N0 = " I_NORMALMATRICES "[normidx].xyz;\n"
"float3 N1 = " I_NORMALMATRICES "[normidx + 1].xyz;\n"
"float3 N2 = " I_NORMALMATRICES "[normidx + 2].xyz;\n");
}
}
else
{
// One shared matrix
out.Write("float4 P0 = " I_POSNORMALMATRIX "[0];\n"
"float4 P1 = " I_POSNORMALMATRIX "[1];\n"
"float4 P2 = " I_POSNORMALMATRIX "[2];\n");
if ((uid_data->components & VB_HAS_NORMAL) != 0)
{
out.Write("float3 N0 = " I_POSNORMALMATRIX "[3].xyz;\n"
"float3 N1 = " I_POSNORMALMATRIX "[4].xyz;\n"
"float3 N2 = " I_POSNORMALMATRIX "[5].xyz;\n");
}
}
out.Write("// Multiply the position vector by the position matrix\n"
"float4 pos = float4(dot(P0, rawpos), dot(P1, rawpos), dot(P2, rawpos), 1.0);\n");
if ((uid_data->components & VB_HAS_NORMAL) != 0)
{
if ((uid_data->components & VB_HAS_TANGENT) == 0)
out.Write("float3 rawtangent = " I_CACHED_TANGENT ".xyz;\n");
if ((uid_data->components & VB_HAS_BINORMAL) == 0)
out.Write("float3 rawbinormal = " I_CACHED_BINORMAL ".xyz;\n");
// The scale of the transform matrix is used to control the size of the emboss map effect, by
// changing the scale of the transformed binormals (which only get used by emboss map texgens).
// By normalising the first transformed normal (which is used by lighting calculations and needs
// to be unit length), the same transform matrix can do double duty, scaling for emboss mapping,
// and not scaling for lighting.
out.Write("float3 _normal = normalize(float3(dot(N0, rawnormal), dot(N1, rawnormal), dot(N2, "
"rawnormal)));\n"
"float3 _tangent = float3(dot(N0, rawtangent), dot(N1, rawtangent), dot(N2, "
"rawtangent));\n"
"float3 _binormal = float3(dot(N0, rawbinormal), dot(N1, rawbinormal), dot(N2, "
"rawbinormal));\n");
}
else
{
out.Write("float3 _normal = float3(0.0, 0.0, 0.0);\n");
out.Write("float3 _binormal = float3(0.0, 0.0, 0.0);\n");
out.Write("float3 _tangent = float3(0.0, 0.0, 0.0);\n");
}
out.Write("o.pos = float4(dot(" I_PROJECTION "[0], pos), dot(" I_PROJECTION
"[1], pos), dot(" I_PROJECTION "[2], pos), dot(" I_PROJECTION "[3], pos));\n");
out.Write("int4 lacc;\n"
"float3 ldir, h, cosAttn, distAttn;\n"
"float dist, dist2, attn;\n");
GenerateLightingShaderCode(out, uid_data->lighting, "vertex_color_", "o.colors_");
// transform texcoords
out.Write("float4 coord = float4(0.0, 0.0, 1.0, 1.0);\n");
for (u32 i = 0; i < uid_data->numTexGens; ++i)
{
auto& texinfo = uid_data->texMtxInfo[i];
out.Write("{{\n");
out.Write("coord = float4(0.0, 0.0, 1.0, 1.0);\n");
switch (texinfo.sourcerow)
{
case SourceRow::Geom:
out.Write("coord.xyz = rawpos.xyz;\n");
break;
case SourceRow::Normal:
if ((uid_data->components & VB_HAS_NORMAL) != 0)
{
out.Write("coord.xyz = rawnormal.xyz;\n");
}
break;
case SourceRow::Colors:
ASSERT(texinfo.texgentype == TexGenType::Color0 || texinfo.texgentype == TexGenType::Color1);
break;
case SourceRow::BinormalT:
if ((uid_data->components & VB_HAS_TANGENT) != 0)
{
out.Write("coord.xyz = rawtangent.xyz;\n");
}
break;
case SourceRow::BinormalB:
if ((uid_data->components & VB_HAS_BINORMAL) != 0)
{
out.Write("coord.xyz = rawbinormal.xyz;\n");
}
break;
default:
ASSERT(texinfo.sourcerow >= SourceRow::Tex0 && texinfo.sourcerow <= SourceRow::Tex7);
u32 texnum = static_cast<u32>(texinfo.sourcerow) - static_cast<u32>(SourceRow::Tex0);
if ((uid_data->components & (VB_HAS_UV0 << (texnum))) != 0)
{
out.Write("coord = float4(rawtex{}.x, rawtex{}.y, 1.0, 1.0);\n", texnum, texnum);
}
break;
}
// Input form of AB11 sets z element to 1.0
if (texinfo.inputform == TexInputForm::AB11)
out.Write("coord.z = 1.0;\n");
// Convert NaNs to 1 - needed to fix eyelids in Shadow the Hedgehog during cutscenes
// See https://bugs.dolphin-emu.org/issues/11458
out.Write("// Convert NaN to 1\n");
out.Write("if (dolphin_isnan(coord.x)) coord.x = 1.0;\n");
out.Write("if (dolphin_isnan(coord.y)) coord.y = 1.0;\n");
out.Write("if (dolphin_isnan(coord.z)) coord.z = 1.0;\n");
// first transformation
switch (texinfo.texgentype)
{
case TexGenType::EmbossMap: // calculate tex coords into bump map
// transform the light dir into tangent space
out.Write("ldir = normalize(" LIGHT_POS ".xyz - pos.xyz);\n",
LIGHT_POS_PARAMS(texinfo.embosslightshift));
out.Write(
"o.tex{}.xyz = o.tex{}.xyz + float3(dot(ldir, _tangent), dot(ldir, _binormal), 0.0);\n",
i, texinfo.embosssourceshift);
break;
case TexGenType::Color0:
out.Write("o.tex{}.xyz = float3(o.colors_0.x, o.colors_0.y, 1);\n", i);
break;
case TexGenType::Color1:
out.Write("o.tex{}.xyz = float3(o.colors_1.x, o.colors_1.y, 1);\n", i);
break;
case TexGenType::Regular:
default:
if ((uid_data->components & (VB_HAS_TEXMTXIDX0 << i)) != 0)
{
out.Write("int tmp = int(rawtex{}.z);\n", i);
if (static_cast<TexSize>((uid_data->texMtxInfo_n_projection >> i) & 1) == TexSize::STQ)
{
out.Write("o.tex{}.xyz = float3(dot(coord, " I_TRANSFORMMATRICES
"[tmp]), dot(coord, " I_TRANSFORMMATRICES
"[tmp+1]), dot(coord, " I_TRANSFORMMATRICES "[tmp+2]));\n",
i);
}
else
{
out.Write("o.tex{}.xyz = float3(dot(coord, " I_TRANSFORMMATRICES
"[tmp]), dot(coord, " I_TRANSFORMMATRICES "[tmp+1]), 1);\n",
i);
}
}
else
{
if (static_cast<TexSize>((uid_data->texMtxInfo_n_projection >> i) & 1) == TexSize::STQ)
{
out.Write("o.tex{}.xyz = float3(dot(coord, " I_TEXMATRICES
"[{}]), dot(coord, " I_TEXMATRICES "[{}]), dot(coord, " I_TEXMATRICES
"[{}]));\n",
i, 3 * i, 3 * i + 1, 3 * i + 2);
}
else
{
out.Write("o.tex{}.xyz = float3(dot(coord, " I_TEXMATRICES
"[{}]), dot(coord, " I_TEXMATRICES "[{}]), 1);\n",
i, 3 * i, 3 * i + 1);
}
}
break;
}
// CHECKME: does this only work for regular tex gen types?
if (uid_data->dualTexTrans_enabled && texinfo.texgentype == TexGenType::Regular)
{
auto& postInfo = uid_data->postMtxInfo[i];
out.Write("float4 P0 = " I_POSTTRANSFORMMATRICES "[{}];\n"
"float4 P1 = " I_POSTTRANSFORMMATRICES "[{}];\n"
"float4 P2 = " I_POSTTRANSFORMMATRICES "[{}];\n",
postInfo.index & 0x3f, (postInfo.index + 1) & 0x3f, (postInfo.index + 2) & 0x3f);
if (postInfo.normalize)
out.Write("o.tex{}.xyz = normalize(o.tex{}.xyz);\n", i, i);
// multiply by postmatrix
out.Write(
"o.tex{0}.xyz = float3(dot(P0.xyz, o.tex{0}.xyz) + P0.w, dot(P1.xyz, o.tex{0}.xyz) + "
"P1.w, dot(P2.xyz, o.tex{0}.xyz) + P2.w);\n",
i);
}
// When q is 0, the GameCube appears to have a special case
// This can be seen in devkitPro's neheGX Lesson08 example for Wii
// Makes differences in Rogue Squadron 3 (Hoth sky) and The Last Story (shadow culling)
// TODO: check if this only affects XF_TEXGEN_REGULAR
if (texinfo.texgentype == TexGenType::Regular)
{
out.Write(
"if(o.tex{0}.z == 0.0f)\n"
"\to.tex{0}.xy = clamp(o.tex{0}.xy / 2.0f, float2(-1.0f,-1.0f), float2(1.0f,1.0f));\n",
i);
}
out.Write("}}\n");
}
if (uid_data->vs_expand == VSExpand::Line)
{
out.Write("// Line expansion\n"
"uint other_id = vertex_id;\n"
"if (is_bottom) {{\n"
" other_id -= 1;\n"
"}} else {{\n"
" other_id += 1;\n"
"}}\n"
"InputData other = input_buffer[other_id];\n");
if (uid_data->position_has_3_elems)
out.Write("float4 other_pos = float4(other.pos0, other.pos1, other.pos2, 1.0f);\n");
else
out.Write("float4 other_pos = float4(other.pos0, other.pos1, 0.0f, 1.0f);\n");
if (uid_data->components & VB_HAS_POSMTXIDX)
{
out.Write("uint other_posidx = other.posmtx & 0xff;\n"
"float4 other_p0 = " I_TRANSFORMMATRICES "[other_posidx];\n"
"float4 other_p1 = " I_TRANSFORMMATRICES "[other_posidx + 1];\n"
"float4 other_p2 = " I_TRANSFORMMATRICES "[other_posidx + 2];\n"
"other_pos = float4(dot(other_p0, other_pos), dot(other_p1, other_pos), "
"dot(other_p2, other_pos), 1.0f);\n");
}
else
{
out.Write("other_pos = float4(dot(P0, other_pos), dot(P1, other_pos), dot(P2, other_pos), "
"1.0f);\n");
}
GenerateVSLineExpansion(out, "", uid_data->numTexGens);
}
else if (uid_data->vs_expand == VSExpand::Point)
{
out.Write("// Point expansion\n");
GenerateVSPointExpansion(out, "", uid_data->numTexGens);
}
if (per_pixel_lighting)
{
// When per-pixel lighting is enabled, the vertex colors are passed through
// unmodified so we can evaluate the lighting in the pixel shader.
// Lighting is also still computed in the vertex shader since it can be used to
// generate texture coordinates. We generated them above, so now the colors can
// be reverted to their previous stage.
out.Write("o.colors_0 = vertex_color_0;\n");
out.Write("o.colors_1 = vertex_color_1;\n");
// Note that the numColorChans logic is performed in the pixel shader.
}
else
{
// The number of colors available to TEV is determined by numColorChans.
// We have to provide the fields to match the interface, so set to zero if it's not enabled.
if (uid_data->numColorChans == 0)
out.Write("o.colors_0 = float4(0.0, 0.0, 0.0, 0.0);\n");
if (uid_data->numColorChans <= 1)
out.Write("o.colors_1 = float4(0.0, 0.0, 0.0, 0.0);\n");
}
// clipPos/w needs to be done in pixel shader, not here
if (!host_config.fast_depth_calc)
out.Write("o.clipPos = o.pos;\n");
if (per_pixel_lighting)
{
out.Write("o.Normal = _normal;\n"
"o.WorldPos = pos.xyz;\n");
}
// If we can disable the incorrect depth clipping planes using depth clamping, then we can do
// our own depth clipping and calculate the depth range before the perspective divide if
// necessary.
if (host_config.backend_depth_clamp)
{
// Since we're adjusting z for the depth range before the perspective divide, we have to do our
// own clipping. We want to clip so that -w <= z <= 0, which matches the console -1..0 range.
// We adjust our depth value for clipping purposes to match the perspective projection in the
// software backend, which is a hack to fix Sonic Adventure and Unleashed games.
out.Write("float clipDepth = o.pos.z * (1.0 - 1e-7);\n"
"float clipDist0 = clipDepth + o.pos.w;\n" // Near: z < -w
"float clipDist1 = -clipDepth;\n"); // Far: z > 0
if (host_config.backend_geometry_shaders)
{
out.Write("o.clipDist0 = clipDist0;\n"
"o.clipDist1 = clipDist1;\n");
}
}
else
{
// Same depth adjustment for Sonic. Without depth clamping, it unfortunately
// affects non-clipping uses of depth too.
out.Write("o.pos.z = o.pos.z * (1.0 - 1e-7);\n");
}
// Write the true depth value. If the game uses depth textures, then the pixel shader will
// override it with the correct values if not then early z culling will improve speed.
// There are two different ways to do this, when the depth range is oversized, we process
// the depth range in the vertex shader, if not we let the host driver handle it.
//
// Adjust z for the depth range. We're using an equation which incorperates a depth inversion,
// so we can map the console -1..0 range to the 0..1 range used in the depth buffer.
// We have to handle the depth range in the vertex shader instead of after the perspective
// divide, because some games will use a depth range larger than what is allowed by the
// graphics API. These large depth ranges will still be clipped to the 0..1 range, so these
// games effectively add a depth bias to the values written to the depth buffer.
out.Write("o.pos.z = o.pos.w * " I_PIXELCENTERCORRECTION ".w - "
"o.pos.z * " I_PIXELCENTERCORRECTION ".z;\n");
if (!host_config.backend_clip_control)
{
// If the graphics API doesn't support a depth range of 0..1, then we need to map z to
// the -1..1 range. Unfortunately we have to use a substraction, which is a lossy floating-point
// operation that can introduce a round-trip error.
out.Write("o.pos.z = o.pos.z * 2.0 - o.pos.w;\n");
}
// Correct for negative viewports by mirroring all vertices. We need to negate the height here,
// since the viewport height is already negated by the render backend.
out.Write("o.pos.xy *= sign(" I_PIXELCENTERCORRECTION ".xy * float2(1.0, -1.0));\n");
// The console GPU places the pixel center at 7/12 in screen space unless
// antialiasing is enabled, while D3D and OpenGL place it at 0.5. This results
// in some primitives being placed one pixel too far to the bottom-right,
// which in turn can be critical if it happens for clear quads.
// Hence, we compensate for this pixel center difference so that primitives
// get rasterized correctly.
out.Write("o.pos.xy = o.pos.xy - o.pos.w * " I_PIXELCENTERCORRECTION ".xy;\n");
if (vertex_rounding)
{
// By now our position is in clip space
// however, higher resolutions than the Wii outputs
// cause an additional pixel offset
// due to a higher pixel density
// we need to correct this by converting our
// clip-space position into the Wii's screen-space
// acquire the right pixel and then convert it back
out.Write("if (o.pos.w == 1.0f)\n"
"{{\n"
"\tfloat ss_pixel_x = ((o.pos.x + 1.0f) * (" I_VIEWPORT_SIZE ".x * 0.5f));\n"
"\tfloat ss_pixel_y = ((o.pos.y + 1.0f) * (" I_VIEWPORT_SIZE ".y * 0.5f));\n"
"\tss_pixel_x = round(ss_pixel_x);\n"
"\tss_pixel_y = round(ss_pixel_y);\n"
"\to.pos.x = ((ss_pixel_x / (" I_VIEWPORT_SIZE ".x * 0.5f)) - 1.0f);\n"
"\to.pos.y = ((ss_pixel_y / (" I_VIEWPORT_SIZE ".y * 0.5f)) - 1.0f);\n"
"}}\n");
}
if (host_config.backend_geometry_shaders)
{
AssignVSOutputMembers(out, "vs", "o", uid_data->numTexGens, host_config);
}
else
{
// TODO: Pass interface blocks between shader stages even if geometry shaders
// are not supported, however that will require at least OpenGL 3.2 support.
for (u32 i = 0; i < uid_data->numTexGens; ++i)
out.Write("tex{}.xyz = o.tex{};\n", i, i);
if (!host_config.fast_depth_calc)
out.Write("clipPos = o.clipPos;\n");
if (per_pixel_lighting)
{
out.Write("Normal = o.Normal;\n"
"WorldPos = o.WorldPos;\n");
}
out.Write("colors_0 = o.colors_0;\n"
"colors_1 = o.colors_1;\n");
}
if (host_config.backend_depth_clamp)
{
out.Write("gl_ClipDistance[0] = clipDist0;\n"
"gl_ClipDistance[1] = clipDist1;\n");
}
// Vulkan NDC space has Y pointing down (right-handed NDC space).
if (api_type == APIType::Vulkan)
out.Write("gl_Position = float4(o.pos.x, -o.pos.y, o.pos.z, o.pos.w);\n");
else
out.Write("gl_Position = o.pos;\n");
out.Write("}}\n");
return out;
}