draw_shader_shared.hh

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/* SPDX-FileCopyrightText: 2023 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */
 
#ifndef GPU_SHADER
#  pragma once
 
#  include "GPU_shader.hh"
#  include "GPU_shader_shared_utils.hh"
#  include "draw_defines.hh"
 
struct ViewCullingData;
struct ViewMatrices;
struct ObjectMatrices;
struct ObjectInfos;
struct ObjectBounds;
struct VolumeInfos;
struct CurvesInfos;
struct ObjectAttribute;
struct LayerAttribute;
struct DrawCommand;
struct DispatchCommand;
struct DRWDebugPrintBuffer;
struct DRWDebugVert;
struct DRWDebugDrawBuffer;
struct FrustumCorners;
struct FrustumPlanes;
 
/* __cplusplus is true when compiling with MSL. */
#  if defined(__cplusplus) && !defined(GPU_SHADER)
/* C++ only forward declarations. */
struct Object;
struct Scene;
struct ViewLayer;
struct GPUUniformAttr;
struct GPULayerAttr;
 
namespace blender::draw {
 
struct ObjectRef;
 
}  // namespace blender::draw
 
#  endif
#endif
 
#define DRW_SHADER_SHARED_H
 
#define DRW_RESOURCE_CHUNK_LEN 512
 
/* Define the maximum number of grid we allow in a volume UBO. */
#define DRW_GRID_PER_VOLUME_MAX 16
 
/* Define the maximum number of attribute we allow in a curves UBO.
 * This should be kept in sync with `GPU_ATTR_MAX` */
#define DRW_ATTRIBUTE_PER_CURVES_MAX 15
 
/* -------------------------------------------------------------------- */
#ifndef DRW_VIEW_LEN
/* Single-view case (default). */
#  define drw_view_id 0
#  define DRW_VIEW_LEN 1
#  define DRW_VIEW_SHIFT 0
#  define DRW_VIEW_FROM_RESOURCE_ID
#else
 
/* Multi-view case. */
// #  define DRW_VIEW_LEN 64
uint drw_view_id = 0;
#  define DRW_VIEW_SHIFT \
    ((DRW_VIEW_LEN > 32) ? 6 : \
     (DRW_VIEW_LEN > 16) ? 5 : \
     (DRW_VIEW_LEN > 8)  ? 4 : \
     (DRW_VIEW_LEN > 4)  ? 3 : \
     (DRW_VIEW_LEN > 2)  ? 2 : \
                           1)
#  define DRW_VIEW_MASK ~(0xFFFFFFFFu << DRW_VIEW_SHIFT)
#  define DRW_VIEW_FROM_RESOURCE_ID drw_view_id = (uint(drw_ResourceID) & DRW_VIEW_MASK)
#endif
 
struct FrustumCorners {
  float4 corners[8];
};
BLI_STATIC_ASSERT_ALIGN(FrustumCorners, 16)
 
struct FrustumPlanes {
  /* [0] left
   * [1] right
   * [2] bottom
   * [3] top
   * [4] near
   * [5] far */
  float4 planes[6];
};
BLI_STATIC_ASSERT_ALIGN(FrustumPlanes, 16)
 
struct ViewCullingData {
  FrustumCorners frustum_corners;
  FrustumPlanes frustum_planes;
  float4 bound_sphere;
};
BLI_STATIC_ASSERT_ALIGN(ViewCullingData, 16)
 
struct ViewMatrices {
  float4x4 viewmat;
  float4x4 viewinv;
  float4x4 winmat;
  float4x4 wininv;
};
BLI_STATIC_ASSERT_ALIGN(ViewMatrices, 16)
 
/* Do not override old definitions if the shader uses this header but not shader info. */
#ifdef USE_GPU_SHADER_CREATE_INFO
/* TODO(@fclem): Mass rename. */
#  define ViewMatrix drw_view.viewmat
#  define ViewMatrixInverse drw_view.viewinv
#  define ProjectionMatrix drw_view.winmat
#  define ProjectionMatrixInverse drw_view.wininv
#endif
 
/* -------------------------------------------------------------------- */
struct ObjectMatrices {
  float4x4 model;
  float4x4 model_inverse;
 
#if !defined(GPU_SHADER) && defined(__cplusplus)
  void sync(const Object &object);
  void sync(const float4x4 &model_matrix);
#endif
};
BLI_STATIC_ASSERT_ALIGN(ObjectMatrices, 16)
 
enum eObjectInfoFlag : uint32_t {
  OBJECT_SELECTED = (1u << 0u),
  OBJECT_FROM_DUPLI = (1u << 1u),
  OBJECT_FROM_SET = (1u << 2u),
  OBJECT_ACTIVE = (1u << 3u),
  OBJECT_NEGATIVE_SCALE = (1u << 4u),
  OBJECT_HOLDOUT = (1u << 5u),
  /* Avoid skipped info to change culling. */
  OBJECT_NO_INFO = ~OBJECT_HOLDOUT
};
 
struct ObjectInfos {
#if defined(GPU_SHADER) && !defined(DRAW_FINALIZE_SHADER)
  /* TODO Rename to struct member for GLSL too. */
  float4 orco_mul_bias[2];
  float4 ob_color;
  float4 infos;
#else
  packed_float3 orco_add;
  uint object_attrs_offset;
  packed_float3 orco_mul;
  uint object_attrs_len;
 
  float4 ob_color;
  uint index;
  uint light_and_shadow_set_membership;
  float random;
  eObjectInfoFlag flag;
#endif
 
#if !defined(GPU_SHADER) && defined(__cplusplus)
  void sync();
  void sync(const blender::draw::ObjectRef ref, bool is_active_object);
#endif
};
BLI_STATIC_ASSERT_ALIGN(ObjectInfos, 16)
 
inline uint receiver_light_set_get(ObjectInfos object_infos)
{
#if defined(GPU_SHADER) && !defined(DRAW_FINALIZE_SHADER)
  return floatBitsToUint(object_infos.infos.y) & 0xFFu;
#else
  return object_infos.light_and_shadow_set_membership & 0xFFu;
#endif
}
 
inline uint blocker_shadow_set_get(ObjectInfos object_infos)
{
#if defined(GPU_SHADER) && !defined(DRAW_FINALIZE_SHADER)
  return (floatBitsToUint(object_infos.infos.y) >> 8u) & 0xFFu;
#else
  return (object_infos.light_and_shadow_set_membership >> 8u) & 0xFFu;
#endif
}
 
struct ObjectBounds {
  float4 bounding_corners[4];
  float4 bounding_sphere;
#define _inner_sphere_radius bounding_corners[3].w
 
#if !defined(GPU_SHADER) && defined(__cplusplus)
  void sync();
  void sync(const Object &ob, float inflate_bounds = 0.0f);
  void sync(const float3 &center, const float3 &size);
#endif
};
BLI_STATIC_ASSERT_ALIGN(ObjectBounds, 16)
 
/* Return true if `bounding_corners` are valid. Should be checked before accessing them.
 * Does not guarantee that `bounding_sphere` is valid.
 * Converting these bounds to an `IsectBox` may generate invalid clip planes.
 * For safe `IsectBox` generation check `drw_bounds_are_valid`. */
inline bool drw_bounds_corners_are_valid(ObjectBounds bounds)
{
  return bounds.bounding_sphere.w != -1.0f;
}
 
/* Return true if bounds are ready for culling.
 * In this case, both `bounding_corners` and `bounding_sphere` are valid.
 * These bounds can be safely converted to an `IsectBox` with valid clip planes. */
inline bool drw_bounds_are_valid(ObjectBounds bounds)
{
  return bounds.bounding_sphere.w >= 0.0f;
}
 
/* -------------------------------------------------------------------- */
struct VolumeInfos {
  float4x4 grids_xform[DRW_GRID_PER_VOLUME_MAX];
  float4 color_mul;
  float density_scale;
  float temperature_mul;
  float temperature_bias;
  float _pad;
};
BLI_STATIC_ASSERT_ALIGN(VolumeInfos, 16)
 
struct CurvesInfos {
  uint4 is_point_attribute[DRW_ATTRIBUTE_PER_CURVES_MAX];
};
BLI_STATIC_ASSERT_ALIGN(CurvesInfos, 16)
 
#pragma pack(push, 4)
struct ObjectAttribute {
  /* Workaround the padding cost from alignment requirements.
   * (see GL spec : 7.6.2.2 Standard Uniform Block Layout) */
  float data_x, data_y, data_z, data_w;
  uint hash_code;
 
#if !defined(GPU_SHADER) && defined(__cplusplus)
  bool sync(const blender::draw::ObjectRef &ref, const GPUUniformAttr &attr);
#endif
};
#pragma pack(pop)
BLI_STATIC_ASSERT_ALIGN(ObjectAttribute, 20)
 
#pragma pack(push, 4)
struct LayerAttribute {
  float4 data;
  uint hash_code;
  uint buffer_length; /* Only in the first record. */
  uint _pad1, _pad2;
 
#if !defined(GPU_SHADER) && defined(__cplusplus)
  bool sync(const Scene *scene, const ViewLayer *layer, const GPULayerAttr &attr);
#endif
};
#pragma pack(pop)
BLI_STATIC_ASSERT_ALIGN(LayerAttribute, 32)
 
 
/* -------------------------------------------------------------------- */
struct DrawCommand {
  /* TODO(fclem): Rename */
  uint vertex_len;
  uint instance_len;
  uint vertex_first;
#if defined(GPU_SHADER)
  uint base_index;
#  define _instance_first_array base_index
#else
  union {
    uint base_index;
    /* Use this instead of instance_first_indexed for non indexed draw calls. */
    uint instance_first_array;
  };
#endif
 
  uint instance_first_indexed;
 
  uint _pad0, _pad1, _pad2;
};
BLI_STATIC_ASSERT_ALIGN(DrawCommand, 16)
 
struct DispatchCommand {
  uint num_groups_x;
  uint num_groups_y;
  uint num_groups_z;
  uint _pad0;
};
BLI_STATIC_ASSERT_ALIGN(DispatchCommand, 16)
 
 
/* -------------------------------------------------------------------- */
/* Take the header (DrawCommand) into account. */
#define DRW_DEBUG_PRINT_MAX (8 * 1024) - 4
#define DRW_DEBUG_PRINT_WORD_WRAP_COLUMN 120u
 
/* The debug print buffer is laid-out as the following struct.
 * But we use plain array in shader code instead because of driver issues. */
struct DRWDebugPrintBuffer {
  DrawCommand command;
  uint char_array[DRW_DEBUG_PRINT_MAX];
};
BLI_STATIC_ASSERT_ALIGN(DRWDebugPrintBuffer, 16)
 
/* Use number of char as vertex count. Equivalent to `DRWDebugPrintBuffer.command.v_count`. */
#define drw_debug_print_cursor drw_debug_print_buf[0]
/* Reuse first instance as row index as we don't use instancing. Equivalent to
 * `DRWDebugPrintBuffer.command.i_first`. */
#define drw_debug_print_row_shared drw_debug_print_buf[3]
#define drw_debug_print_offset 8
 
/* -------------------------------------------------------------------- */
struct DRWDebugVert {
  /* This is a weird layout, but needed to be able to use DRWDebugVert as
   * a DrawCommand and avoid alignment issues. See drw_debug_verts_buf[] definition. */
  uint pos0;
  uint pos1;
  uint pos2;
  /* Named vert_color to avoid global namespace collision with uniform color. */
  uint vert_color;
};
BLI_STATIC_ASSERT_ALIGN(DRWDebugVert, 16)
 
inline DRWDebugVert debug_vert_make(uint in_pos0, uint in_pos1, uint in_pos2, uint in_vert_color)
{
  DRWDebugVert debug_vert;
  debug_vert.pos0 = in_pos0;
  debug_vert.pos1 = in_pos1;
  debug_vert.pos2 = in_pos2;
  debug_vert.vert_color = in_vert_color;
  return debug_vert;
}
 
/* Take the header (DrawCommand) into account. */
#define DRW_DEBUG_DRAW_VERT_MAX (64 * 8192) - 1
 
/* The debug draw buffer is laid-out as the following struct.
 * But we use plain array in shader code instead because of driver issues. */
struct DRWDebugDrawBuffer {
  DrawCommand command;
  DRWDebugVert verts[DRW_DEBUG_DRAW_VERT_MAX];
};
BLI_STATIC_ASSERT_ALIGN(DRWDebugPrintBuffer, 16)
 
/* Equivalent to `DRWDebugDrawBuffer.command.v_count`. */
#define drw_debug_draw_v_count drw_debug_verts_buf[0].pos0
#define drw_debug_draw_offset 2