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fixe IW engine

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Orange
2026-04-26 01:55:08 +03:00
parent e1d6c38a8e
commit 3e6b0e7180
1 changed files with 15 additions and 16 deletions
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31
source/engines/iw_engine/formulas.cpp
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@@ -38,25 +38,24 @@ namespace omath::iw_engine
Mat4X4 calc_perspective_projection_matrix(const float field_of_view, const float aspect_ratio, const float near,
const float far, const NDCDepthRange ndc_depth_range) noexcept
{
// NOTE: Need magic number to fix fov calculation, since IW engine inherit Quake proj matrix calculation
constexpr auto k_multiply_factor = 0.75f;
const float fov_half_tan = std::tan(angles::degrees_to_radians(field_of_view) / 2.f) * k_multiply_factor;
// InfinityWard Engine (inherited from Quake) stores FOV as horizontal FOV at a 4:3
// reference aspect. Convert to true vertical FOV, then delegate to the
// standard vertical-FOV left-handed builder with the caller's actual
// aspect ratio.
// vfov = 2 · atan( tan(hfov_4:3 / 2) / (4/3) )
constexpr float k_source_reference_aspect = 4.f / 3.f;
const float half_hfov_4_3 = angles::degrees_to_radians(field_of_view) / 2.f;
const float vfov_deg = angles::radians_to_degrees(
2.f * std::atan(std::tan(half_hfov_4_3) / k_source_reference_aspect));
if (ndc_depth_range == NDCDepthRange::ZERO_TO_ONE)
return {
{1.f / (aspect_ratio * fov_half_tan), 0, 0, 0},
{0, 1.f / (fov_half_tan), 0, 0},
{0, 0, far / (far - near), -(near * far) / (far - near)},
{0, 0, 1, 0},
};
return mat_perspective_left_handed<
float, MatStoreType::ROW_MAJOR, NDCDepthRange::ZERO_TO_ONE>(
vfov_deg, aspect_ratio, near, far);
if (ndc_depth_range == NDCDepthRange::NEGATIVE_ONE_TO_ONE)
return {
{1.f / (aspect_ratio * fov_half_tan), 0, 0, 0},
{0, 1.f / (fov_half_tan), 0, 0},
{0, 0, (far + near) / (far - near), -(2.f * far * near) / (far - near)},
{0, 0, 1, 0},
};
return mat_perspective_left_handed<
float, MatStoreType::ROW_MAJOR, NDCDepthRange::NEGATIVE_ONE_TO_ONE>(
vfov_deg, aspect_ratio, near, far);
std::unreachable();
};
} // namespace omath::iw_engine