path: root/source/blender/draw/engines/eevee_next/shaders/eevee_attributes_lib.glsl

#pragma BLENDER_REQUIRE(common_view_lib.glsl)
#pragma BLENDER_REQUIRE(common_math_lib.glsl)
#pragma BLENDER_REQUIRE(gpu_shader_codegen_lib.glsl)

#if defined(MAT_GEOM_MESH)

/* -------------------------------------------------------------------- */
/** \name Mesh
 *
 * Mesh objects attributes are loaded using vertex input attributes.
 * \{ */

#  ifdef OBINFO_LIB
vec3 attr_load_orco(vec4 orco)
{
  /* We know when there is no orco layer when orco.w is 1.0 because it uses the generic vertex
   * attrib (which is [0,0,0,1]). */
  if (orco.w == 1.0) {
    /* If the object does not have any deformation, the orco layer calculation is done on the fly
     * using the orco_madd factors. */
    return OrcoTexCoFactors[0].xyz + pos * OrcoTexCoFactors[1].xyz;
  }
  return orco.xyz * 0.5 + 0.5;
}
#  endif
vec4 attr_load_tangent(vec4 tangent)
{
  tangent.xyz = safe_normalize(normal_object_to_world(tangent.xyz));
  return tangent;
}
vec4 attr_load_vec4(vec4 attr)
{
  return attr;
}
vec3 attr_load_vec3(vec3 attr)
{
  return attr;
}
vec2 attr_load_vec2(vec2 attr)
{
  return attr;
}
float attr_load_float(float attr)
{
  return attr;
}
vec4 attr_load_color(vec4 attr)
{
  return attr;
}
vec3 attr_load_uv(vec3 attr)
{
  return attr;
}

/** \} */

#elif defined(MAT_GEOM_GPENCIL)

/* -------------------------------------------------------------------- */
/** \name Grease Pencil
 *
 * Grease Pencil objects have one uv and one color attribute layer.
 * \{ */

/* Globals to feed the load functions. */
vec2 g_uvs;
vec4 g_color;

#  ifdef OBINFO_LIB
vec3 attr_load_orco(vec4 orco)
{
  vec3 lP = point_world_to_object(interp.P);
  return OrcoTexCoFactors[0].xyz + lP * OrcoTexCoFactors[1].xyz;
}
#  endif
vec4 attr_load_tangent(vec4 tangent)
{
  return vec4(0.0, 0.0, 0.0, 1.0);
}
vec3 attr_load_uv(vec3 dummy)
{
  return vec3(g_uvs, 0.0);
}
vec4 attr_load_color(vec4 dummy)
{
  return g_color;
}
vec4 attr_load_vec4(vec4 attr)
{
  return vec4(0.0);
}
vec3 attr_load_vec3(vec3 attr)
{
  return vec3(0.0);
}
vec2 attr_load_vec2(vec2 attr)
{
  return vec2(0.0);
}
float attr_load_float(float attr)
{
  return 0.0;
}

/** \} */

#elif defined(MAT_GEOM_CURVES)

/* -------------------------------------------------------------------- */
/** \name Curve
 *
 * Curve objects loads attributes from buffers through sampler buffers.
 * Per attribute scope follows loading order.
 * \{ */

#  ifdef OBINFO_LIB
vec3 attr_load_orco(vec4 orco)
{
  vec3 P = hair_get_strand_pos();
  vec3 lP = transform_point(ModelMatrixInverse, P);
  return OrcoTexCoFactors[0].xyz + lP * OrcoTexCoFactors[1].xyz;
}
#  endif

int g_curves_attr_id = 0;

/* Return the index to use for looking up the attribute value in the sampler
 * based on the attribute scope (point or spline). */
int curves_attribute_element_id()
{
  int id = interp.curves_strand_id;
  if (drw_curves.is_point_attribute[g_curves_attr_id][0] != 0) {
#  ifdef COMMON_HAIR_LIB
    id = hair_get_base_id();
#  endif
  }

  g_curves_attr_id += 1;
  return id;
}

vec4 attr_load_tangent(samplerBuffer cd_buf)
{
  /* Not supported for the moment. */
  return vec4(0.0, 0.0, 0.0, 1.0);
}
vec3 attr_load_uv(samplerBuffer cd_buf)
{
  return texelFetch(cd_buf, interp.curves_strand_id).rgb;
}
vec4 attr_load_color(samplerBuffer cd_buf)
{
  return texelFetch(cd_buf, interp.curves_strand_id).rgba;
}
vec4 attr_load_vec4(samplerBuffer cd_buf)
{
  return texelFetch(cd_buf, curves_attribute_element_id()).rgba;
}
vec3 attr_load_vec3(samplerBuffer cd_buf)
{
  return texelFetch(cd_buf, curves_attribute_element_id()).rgb;
}
vec2 attr_load_vec2(samplerBuffer cd_buf)
{
  return texelFetch(cd_buf, curves_attribute_element_id()).rg;
}
float attr_load_float(samplerBuffer cd_buf)
{
  return texelFetch(cd_buf, curves_attribute_element_id()).r;
}

/** \} */

#elif defined(MAT_GEOM_VOLUME)

/* -------------------------------------------------------------------- */
/** \name Volume
 *
 * Volume objects loads attributes from "grids" in the form of 3D textures.
 * Per grid transform order is following loading order.
 * \{ */

#  ifndef OBINFO_LIB
#    error draw_object_infos is mandatory for volume objects
#  endif

vec3 g_orco;
int g_attr_id = 0;

vec3 grid_coordinates()
{
  vec3 co = g_orco;
  /* Optional per-grid transform. */
  if (drw_volume.grids_xform[g_attr_id][3][3] != 0.0) {
    co = (drw_volume.grids_xform[g_attr_id] * vec4(objectPosition, 1.0)).xyz;
  }
  g_attr_id += 1;
  return co;
}

vec3 attr_load_orco(sampler3D tex)
{
  g_attr_id += 1;
  return g_orco;
}
vec4 attr_load_tangent(sampler3D tex)
{
  attr_id += 1;
  return vec4(0);
}
vec4 attr_load_vec4(sampler3D tex)
{
  return texture(tex, grid_coordinates());
}
vec3 attr_load_vec3(sampler3D tex)
{
  return texture(tex, grid_coordinates()).rgb;
}
vec2 attr_load_vec2(sampler3D tex)
{
  return texture(tex, grid_coordinates()).rg;
}
float attr_load_float(sampler3D tex)
{
  return texture(tex, grid_coordinates()).r;
}
vec4 attr_load_color(sampler3D tex)
{
  return texture(tex, grid_coordinates());
}
vec3 attr_load_uv(sampler3D attr)
{
  attr_id += 1;
  return vec3(0);
}

/** \} */

#elif defined(MAT_GEOM_WORLD)

/* -------------------------------------------------------------------- */
/** \name World
 *
 * World has no attributes other than orco.
 * \{ */

vec3 attr_load_orco(vec4 orco)
{
  return -g_data.N;
}
vec4 attr_load_tangent(vec4 tangent)
{
  return vec4(0);
}
vec4 attr_load_vec4(vec4 attr)
{
  return vec4(0);
}
vec3 attr_load_vec3(vec3 attr)
{
  return vec3(0);
}
vec2 attr_load_vec2(vec2 attr)
{
  return vec2(0);
}
float attr_load_float(float attr)
{
  return 0.0;
}
vec4 attr_load_color(vec4 attr)
{
  return vec4(0);
}
vec3 attr_load_uv(vec3 attr)
{
  return vec3(0);
}

/** \} */

#endif

/* -------------------------------------------------------------------- */
/** \name Volume Attribute post
 *
 * TODO(@fclem): These implementation details should concern the DRWManager and not be a fix on
 * the engine side. But as of now, the engines are responsible for loading the attributes.
 *
 * \{ */

#if defined(MAT_GEOM_VOLUME)

float attr_load_temperature_post(float attr)
{
  /* Bring the into standard range without having to modify the grid values */
  attr = (attr > 0.01) ? (attr * drw_volume.temperature_mul + drw_volume.temperature_bias) : 0.0;
  return attr;
}
vec4 attr_load_color_post(vec4 attr)
{
  /* Density is premultiplied for interpolation, divide it out here. */
  attr.rgb *= safe_rcp(attr.a);
  attr.rgb *= drw_volume.color_mul.rgb;
  attr.a = 1.0;
  return attr;
}

#else /* Noop for any other surface. */

float attr_load_temperature_post(float attr)
{
  return attr;
}
vec4 attr_load_color_post(vec4 attr)
{
  return attr;
}

#endif

/** \} */