tornavis/source/blender/gpu/GPU_shader_shared_utils.h

115 lines
3.3 KiB
C

/* SPDX-FileCopyrightText: 2022 Blender Authors
*
* SPDX-License-Identifier: GPL-2.0-or-later */
/** \file
* \ingroup gpu
*
* Glue definition to make shared declaration of struct & functions work in both C / C++ and GLSL.
* We use the same vector and matrix types as Blender C++. Some math functions are defined to use
* the float version to match the GLSL syntax.
* This file can be used for C & C++ code and the syntax used should follow the same rules.
* Some preprocessing is done by the GPU back-end to make it GLSL compatible.
*
* IMPORTANT:
* - Always use `u` suffix for enum values. GLSL do not support implicit cast.
* - Define all values. This is in order to simplify custom pre-processor code.
* - (C++ only) Always use `uint32_t` as underlying type (`enum eMyEnum : uint32_t`).
* - (C only) do NOT use the enum type inside UBO/SSBO structs and use `uint` instead.
* - Use float suffix by default for float literals to avoid double promotion in C++.
* - Pack one float or int after a vec3/ivec3 to fulfill alignment rules.
*
* NOTE: Due to alignment restriction and buggy drivers, do not try to use mat3 inside structs.
* NOTE: (UBO only) Do not use arrays of float. They are padded to arrays of vec4 and are not worth
* it. This does not apply to SSBO.
*
* IMPORTANT: Do not forget to align mat4, vec3 and vec4 to 16 bytes, and vec2 to 8 bytes.
*
* NOTE: You can use bool type using bool1 a int boolean type matching the GLSL type.
*/
#ifdef GPU_SHADER
# define BLI_STATIC_ASSERT_ALIGN(type_, align_)
# define BLI_STATIC_ASSERT_SIZE(type_, size_)
# define static
# define inline
# define cosf cos
# define sinf sin
# define tanf tan
# define acosf acos
# define asinf asin
# define atanf atan
# define floorf floor
# define ceilf ceil
# define sqrtf sqrt
# define expf exp
# define bool1 bool
/* Type name collision with Metal shading language - These type-names are already defined. */
# ifndef GPU_METAL
# define float2 vec2
# define float3 vec3
# define float3x4 mat3x4
# define float4 vec4
# define float4x4 mat4
# define int2 ivec2
# define int3 ivec3
# define int4 ivec4
# define uint2 uvec2
# define uint3 uvec3
# define uint4 uvec4
# define bool2 bvec2
# define bool3 bvec3
# define bool4 bvec4
# define packed_float3 vec3
# define packed_int3 int3
# endif
#else /* C / C++ */
# pragma once
# include "BLI_assert.h"
# ifdef __cplusplus
# include "BLI_math_matrix_types.hh"
# include "BLI_math_vector_types.hh"
using blender::float2;
using blender::float3;
using blender::float3x4;
using blender::float4;
using blender::float4x4;
using blender::int2;
using blender::int3;
using blender::int4;
using blender::uint2;
using blender::uint3;
using blender::uint4;
using bool1 = int;
using bool2 = blender::int2;
using bool3 = blender::int3;
using bool4 = blender::int4;
using packed_float3 = blender::float3;
using packed_int3 = blender::int3;
# else /* C */
typedef float float2[2];
typedef float float3[3];
typedef float float4[4];
typedef float float4x4[4][4];
typedef float float3x4[3][4];
typedef int int2[2];
typedef int int3[2];
typedef int int4[4];
typedef uint uint2[2];
typedef uint uint3[3];
typedef uint uint4[4];
typedef int bool1;
typedef int bool2[2];
typedef int bool3[2];
typedef int bool4[4];
typedef float3 packed_float3;
typedef int3 packed_int3;
# endif
#endif