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video_core: Use epsilons for clip planes (#6945)

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* video_core: Use epsilons for clip planes

* video_core: Add comments
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GPUCode 2023-09-11 00:29:55 +03:00 committed by GitHub
parent 3e254d01ee
commit 6aa31d6ec2
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GPG key ID: 4AEE18F83AFDEB23
2 changed files with 23 additions and 4 deletions
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19
src/video_core/renderer_opengl/gl_shader_gen.cpp
View file

@ -1717,7 +1717,12 @@ ShaderDecompiler::ProgramResult GenerateTrivialVertexShader(bool separable_shade
out += UniformBlockDef;
// Certain games render 2D elements very close to clip plane 0 resulting in very tiny
// negative/positive z values when computing with f32 precision,
// causing some vertices to get erroneously clipped. To workaround this problem,
// we can use a very small epsilon value for clip plane comparison.
out += R"(
const float EPSILON_Z = 0.00000001f;
void main() {
primary_color = vert_color;
@ -1727,10 +1732,14 @@ void main() {
texcoord0_w = vert_texcoord0_w;
normquat = vert_normquat;
view = vert_view;
gl_Position = vert_position;
vec4 vtx_pos = vert_position;
if (abs(vtx_pos.z) < EPSILON_Z) {
vtx_pos.z = 0.f;
}
gl_Position = vtx_pos;
#if !defined(CITRA_GLES) || defined(GL_EXT_clip_cull_distance)
gl_ClipDistance[0] = -vert_position.z; // fixed PICA clipping plane z <= 0
gl_ClipDistance[1] = dot(clip_coef, vert_position);
gl_ClipDistance[0] = -vtx_pos.z; // fixed PICA clipping plane z <= 0
gl_ClipDistance[1] = dot(clip_coef, vtx_pos);
#endif // !defined(CITRA_GLES) || defined(GL_EXT_clip_cull_distance)
}
)";
@ -1830,6 +1839,7 @@ struct Vertex {
return "0.0";
};
out += "const float EPSILON_Z = 0.00000001f;\n\n";
out += "vec4 GetVertexQuaternion(Vertex vtx) {\n";
out += " return vec4(" + semantic(VSOutputAttributes::QUATERNION_X) + ", " +
semantic(VSOutputAttributes::QUATERNION_Y) + ", " +
@ -1842,6 +1852,9 @@ struct Vertex {
semantic(VSOutputAttributes::POSITION_Y) + ", " +
semantic(VSOutputAttributes::POSITION_Z) + ", " +
semantic(VSOutputAttributes::POSITION_W) + ");\n";
out += " if (abs(vtx_pos.z) < EPSILON_Z) {\n";
out += " vtx_pos.z = 0.f;\n";
out += " }\n";
out += " gl_Position = vtx_pos;\n";
out += "#if !defined(CITRA_GLES) || defined(GL_EXT_clip_cull_distance)\n";
out += " gl_ClipDistance[0] = -vtx_pos.z;\n"; // fixed PICA clipping plane z <= 0

8
src/video_core/renderer_software/sw_rasterizer.cpp
View file

@ -27,6 +27,12 @@ using Pica::TexturingRegs;
using Pica::Texture::LookupTexture;
using Pica::Texture::TextureInfo;
// Certain games render 2D elements very close to clip plane 0 resulting in very tiny
// negative/positive z values when computing with f32 precision,
// causing some vertices to get erroneously clipped. To workaround this problem,
// we can use a very small epsilon value for clip plane comparison.
constexpr f32 EPSILON_Z = 0.00000001f;
struct Vertex : Pica::Shader::OutputVertex {
Vertex(const OutputVertex& v) : OutputVertex(v) {}
@ -73,7 +79,7 @@ public:
: pos(f24::Zero()), coeffs(coeffs), bias(bias) {}
bool IsInside(const Vertex& vertex) const {
return Common::Dot(vertex.pos + bias, coeffs) >= f24::Zero();
return Common::Dot(vertex.pos + bias, coeffs) >= f24::FromFloat32(-EPSILON_Z);
}
bool IsOutSide(const Vertex& vertex) const {