glsl: make sampler/image scalar types

[mesa.git] / src / compiler / glsl_types.h

/* -*- c++ -*- */
/*
 * Copyright © 2009 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#ifndef GLSL_TYPES_H
#define GLSL_TYPES_H

#include <string.h>
#include <assert.h>

#ifdef __cplusplus
extern "C" {
#endif

struct _mesa_glsl_parse_state;
struct glsl_symbol_table;

extern void
_mesa_glsl_initialize_types(struct _mesa_glsl_parse_state *state);

extern void
_mesa_glsl_release_types(void);

#ifdef __cplusplus
}
#endif

enum glsl_base_type {
   /* Note: GLSL_TYPE_UINT, GLSL_TYPE_INT, and GLSL_TYPE_FLOAT must be 0, 1,
    * and 2 so that they will fit in the 2 bits of glsl_type::sampled_type.
    */
   GLSL_TYPE_UINT = 0,
   GLSL_TYPE_INT,
   GLSL_TYPE_FLOAT,
   GLSL_TYPE_DOUBLE,
   GLSL_TYPE_UINT64,
   GLSL_TYPE_INT64,
   GLSL_TYPE_BOOL,
   GLSL_TYPE_SAMPLER,
   GLSL_TYPE_IMAGE,
   GLSL_TYPE_ATOMIC_UINT,
   GLSL_TYPE_STRUCT,
   GLSL_TYPE_INTERFACE,
   GLSL_TYPE_ARRAY,
   GLSL_TYPE_VOID,
   GLSL_TYPE_SUBROUTINE,
   GLSL_TYPE_FUNCTION,
   GLSL_TYPE_ERROR
};

static inline bool glsl_base_type_is_64bit(enum glsl_base_type type)
{
   return type == GLSL_TYPE_DOUBLE ||
          type == GLSL_TYPE_UINT64 ||
          type == GLSL_TYPE_INT64  ||
          type == GLSL_TYPE_IMAGE  ||
          type == GLSL_TYPE_SAMPLER;
}

enum glsl_sampler_dim {
   GLSL_SAMPLER_DIM_1D = 0,
   GLSL_SAMPLER_DIM_2D,
   GLSL_SAMPLER_DIM_3D,
   GLSL_SAMPLER_DIM_CUBE,
   GLSL_SAMPLER_DIM_RECT,
   GLSL_SAMPLER_DIM_BUF,
   GLSL_SAMPLER_DIM_EXTERNAL,
   GLSL_SAMPLER_DIM_MS,
   GLSL_SAMPLER_DIM_SUBPASS, /* for vulkan input attachments */
   GLSL_SAMPLER_DIM_SUBPASS_MS, /* for multisampled vulkan input attachments */
};

enum glsl_interface_packing {
   GLSL_INTERFACE_PACKING_STD140,
   GLSL_INTERFACE_PACKING_SHARED,
   GLSL_INTERFACE_PACKING_PACKED,
   GLSL_INTERFACE_PACKING_STD430
};

enum glsl_matrix_layout {
   /**
    * The layout of the matrix is inherited from the object containing the
    * matrix (the top level structure or the uniform block).
    */
   GLSL_MATRIX_LAYOUT_INHERITED,

   /**
    * Explicit column-major layout
    *
    * If a uniform block doesn't have an explicit layout set, it will default
    * to this layout.
    */
   GLSL_MATRIX_LAYOUT_COLUMN_MAJOR,

   /**
    * Row-major layout
    */
   GLSL_MATRIX_LAYOUT_ROW_MAJOR
};

enum {
   GLSL_PRECISION_NONE = 0,
   GLSL_PRECISION_HIGH,
   GLSL_PRECISION_MEDIUM,
   GLSL_PRECISION_LOW
};

#ifdef __cplusplus
#include "GL/gl.h"
#include "util/ralloc.h"
#include "main/mtypes.h" /* for gl_texture_index, C++'s enum rules are broken */

struct glsl_type {
   GLenum gl_type;
   glsl_base_type base_type;

   unsigned sampler_dimensionality:4; /**< \see glsl_sampler_dim */
   unsigned sampler_shadow:1;
   unsigned sampler_array:1;
   unsigned sampled_type:2;    /**< Type of data returned using this
                                * sampler or image.  Only \c
                                * GLSL_TYPE_FLOAT, \c GLSL_TYPE_INT,
                                * and \c GLSL_TYPE_UINT are valid.
                                */
   unsigned interface_packing:2;
   unsigned interface_row_major:1;

   /* Callers of this ralloc-based new need not call delete. It's
    * easier to just ralloc_free 'mem_ctx' (or any of its ancestors). */
   static void* operator new(size_t size)
   {
      mtx_lock(&glsl_type::mutex);

      /* mem_ctx should have been created by the static members */
      assert(glsl_type::mem_ctx != NULL);

      void *type;

      type = ralloc_size(glsl_type::mem_ctx, size);
      assert(type != NULL);

      mtx_unlock(&glsl_type::mutex);

      return type;
   }

   /* If the user *does* call delete, that's OK, we will just
    * ralloc_free in that case. */
   static void operator delete(void *type)
   {
      mtx_lock(&glsl_type::mutex);
      ralloc_free(type);
      mtx_unlock(&glsl_type::mutex);
   }

   /**
    * \name Vector and matrix element counts
    *
    * For scalars, each of these values will be 1.  For non-numeric types
    * these will be 0.
    */
   /*@{*/
   uint8_t vector_elements;    /**< 1, 2, 3, or 4 vector elements. */
   uint8_t matrix_columns;     /**< 1, 2, 3, or 4 matrix columns. */
   /*@}*/

   /**
    * For \c GLSL_TYPE_ARRAY, this is the length of the array.  For
    * \c GLSL_TYPE_STRUCT or \c GLSL_TYPE_INTERFACE, it is the number of
    * elements in the structure and the number of values pointed to by
    * \c fields.structure (below).
    */
   unsigned length;

   /**
    * Name of the data type
    *
    * Will never be \c NULL.
    */
   const char *name;

   /**
    * Subtype of composite data types.
    */
   union {
      const struct glsl_type *array;            /**< Type of array elements. */
      struct glsl_function_param *parameters;   /**< Parameters to function. */
      struct glsl_struct_field *structure;      /**< List of struct fields. */
   } fields;

   /**
    * \name Pointers to various public type singletons
    */
   /*@{*/
#undef  DECL_TYPE
#define DECL_TYPE(NAME, ...) \
   static const glsl_type *const NAME##_type;
#undef  STRUCT_TYPE
#define STRUCT_TYPE(NAME) \
   static const glsl_type *const struct_##NAME##_type;
#include "compiler/builtin_type_macros.h"
   /*@}*/

   /**
    * Convenience accessors for vector types (shorter than get_instance()).
    * @{
    */
   static const glsl_type *vec(unsigned components);
   static const glsl_type *dvec(unsigned components);
   static const glsl_type *ivec(unsigned components);
   static const glsl_type *uvec(unsigned components);
   static const glsl_type *bvec(unsigned components);
   static const glsl_type *i64vec(unsigned components);
   static const glsl_type *u64vec(unsigned components);
   /**@}*/

   /**
    * For numeric and boolean derived types returns the basic scalar type
    *
    * If the type is a numeric or boolean scalar, vector, or matrix type,
    * this function gets the scalar type of the individual components.  For
    * all other types, including arrays of numeric or boolean types, the
    * error type is returned.
    */
   const glsl_type *get_base_type() const;

   /**
    * Get the basic scalar type which this type aggregates.
    *
    * If the type is a numeric or boolean scalar, vector, or matrix, or an
    * array of any of those, this function gets the scalar type of the
    * individual components.  For structs and arrays of structs, this function
    * returns the struct type.  For samplers and arrays of samplers, this
    * function returns the sampler type.
    */
   const glsl_type *get_scalar_type() const;

   /**
    * Get the instance of a built-in scalar, vector, or matrix type
    */
   static const glsl_type *get_instance(unsigned base_type, unsigned rows,
                                        unsigned columns);

   /**
    * Get the instance of a sampler type
    */
   static const glsl_type *get_sampler_instance(enum glsl_sampler_dim dim,
                                                bool shadow,
                                                bool array,
                                                glsl_base_type type);

   static const glsl_type *get_image_instance(enum glsl_sampler_dim dim,
                                              bool array, glsl_base_type type);

   /**
    * Get the instance of an array type
    */
   static const glsl_type *get_array_instance(const glsl_type *base,
                                              unsigned elements);

   /**
    * Get the instance of a record type
    */
   static const glsl_type *get_record_instance(const glsl_struct_field *fields,
                                               unsigned num_fields,
                                               const char *name);

   /**
    * Get the instance of an interface block type
    */
   static const glsl_type *get_interface_instance(const glsl_struct_field *fields,
                                                  unsigned num_fields,
                                                  enum glsl_interface_packing packing,
                                                  bool row_major,
                                                  const char *block_name);

   /**
    * Get the instance of an subroutine type
    */
   static const glsl_type *get_subroutine_instance(const char *subroutine_name);

   /**
    * Get the instance of a function type
    */
   static const glsl_type *get_function_instance(const struct glsl_type *return_type,
                                                 const glsl_function_param *parameters,
                                                 unsigned num_params);

   /**
    * Get the type resulting from a multiplication of \p type_a * \p type_b
    */
   static const glsl_type *get_mul_type(const glsl_type *type_a,
                                        const glsl_type *type_b);

   /**
    * Query the total number of scalars that make up a scalar, vector or matrix
    */
   unsigned components() const
   {
      return vector_elements * matrix_columns;
   }

   /**
    * Calculate the number of components slots required to hold this type
    *
    * This is used to determine how many uniform or varying locations a type
    * might occupy.
    */
   unsigned component_slots() const;

   /**
    * Calculate offset between the base location of the struct in
    * uniform storage and a struct member.
    * For the initial call, length is the index of the member to find the
    * offset for.
    */
   unsigned record_location_offset(unsigned length) const;

   /**
    * Calculate the number of unique values from glGetUniformLocation for the
    * elements of the type.
    *
    * This is used to allocate slots in the UniformRemapTable, the amount of
    * locations may not match with actual used storage space by the driver.
    */
   unsigned uniform_locations() const;

   /**
    * Used to count the number of varyings contained in the type ignoring
    * innermost array elements.
    */
   unsigned varying_count() const;

   /**
    * Calculate the number of attribute slots required to hold this type
    *
    * This implements the language rules of GLSL 1.50 for counting the number
    * of slots used by a vertex attribute.  It also determines the number of
    * varying slots the type will use up in the absence of varying packing
    * (and thus, it can be used to measure the number of varying slots used by
    * the varyings that are generated by lower_packed_varyings).
    *
    * For vertex shader attributes - doubles only take one slot.
    * For inter-shader varyings - dvec3/dvec4 take two slots.
    */
   unsigned count_attribute_slots(bool is_vertex_input) const;

   /**
    * Alignment in bytes of the start of this type in a std140 uniform
    * block.
    */
   unsigned std140_base_alignment(bool row_major) const;

   /** Size in bytes of this type in a std140 uniform block.
    *
    * Note that this is not GL_UNIFORM_SIZE (which is the number of
    * elements in the array)
    */
   unsigned std140_size(bool row_major) const;

   /**
    * Alignment in bytes of the start of this type in a std430 shader
    * storage block.
    */
   unsigned std430_base_alignment(bool row_major) const;

   /**
    * Calculate array stride in bytes of this type in a std430 shader storage
    * block.
    */
   unsigned std430_array_stride(bool row_major) const;

   /**
    * Size in bytes of this type in a std430 shader storage block.
    *
    * Note that this is not GL_BUFFER_SIZE
    */
   unsigned std430_size(bool row_major) const;

   /**
    * \brief Can this type be implicitly converted to another?
    *
    * \return True if the types are identical or if this type can be converted
    *         to \c desired according to Section 4.1.10 of the GLSL spec.
    *
    * \verbatim
    * From page 25 (31 of the pdf) of the GLSL 1.50 spec, Section 4.1.10
    * Implicit Conversions:
    *
    *     In some situations, an expression and its type will be implicitly
    *     converted to a different type. The following table shows all allowed
    *     implicit conversions:
    *
    *     Type of expression | Can be implicitly converted to
    *     --------------------------------------------------
    *     int                  float
    *     uint
    *
    *     ivec2                vec2
    *     uvec2
    *
    *     ivec3                vec3
    *     uvec3
    *
    *     ivec4                vec4
    *     uvec4
    *
    *     There are no implicit array or structure conversions. For example,
    *     an array of int cannot be implicitly converted to an array of float.
    *     There are no implicit conversions between signed and unsigned
    *     integers.
    * \endverbatim
    */
   bool can_implicitly_convert_to(const glsl_type *desired,
                                  _mesa_glsl_parse_state *state) const;

   /**
    * Query whether or not a type is a scalar (non-vector and non-matrix).
    */
   bool is_scalar() const
   {
      return (vector_elements == 1)
         && (base_type >= GLSL_TYPE_UINT)
         && (base_type <= GLSL_TYPE_IMAGE);
   }

   /**
    * Query whether or not a type is a vector
    */
   bool is_vector() const
   {
      return (vector_elements > 1)
         && (matrix_columns == 1)
         && (base_type >= GLSL_TYPE_UINT)
         && (base_type <= GLSL_TYPE_BOOL);
   }

   /**
    * Query whether or not a type is a matrix
    */
   bool is_matrix() const
   {
      /* GLSL only has float matrices. */
      return (matrix_columns > 1) && (base_type == GLSL_TYPE_FLOAT || base_type == GLSL_TYPE_DOUBLE);
   }

   /**
    * Query whether or not a type is a non-array numeric type
    */
   bool is_numeric() const
   {
      return (base_type >= GLSL_TYPE_UINT) && (base_type <= GLSL_TYPE_INT64);
   }

   /**
    * Query whether or not a type is an integral type
    */
   bool is_integer() const
   {
      return (base_type == GLSL_TYPE_UINT) || (base_type == GLSL_TYPE_INT);
   }

   /**
    * Query whether or not a type is a 64-bit integer.
    */
   bool is_integer_64() const
   {
      return base_type == GLSL_TYPE_UINT64 || base_type == GLSL_TYPE_INT64;
   }

   /**
    * Query whether or not a type is a 32-bit or 64-bit integer
    */
   bool is_integer_32_64() const
   {
      return is_integer() || is_integer_64();
   }

   /**
    * Query whether or not type is an integral type, or for struct and array
    * types, contains an integral type.
    */
   bool contains_integer() const;

   /**
    * Query whether or not type is a double type, or for struct, interface and
    * array types, contains a double type.
    */
   bool contains_double() const;

   /**
    * Query whether or not a type is a float type
    */
   bool is_float() const
   {
      return base_type == GLSL_TYPE_FLOAT;
   }

   /**
    * Query whether or not a type is a double type
    */
   bool is_double() const
   {
      return base_type == GLSL_TYPE_DOUBLE;
   }

   /**
    * Query whether a 64-bit type takes two slots.
    */
   bool is_dual_slot() const
   {
      return is_64bit() && vector_elements > 2;
   }

   /**
    * Query whether or not a type is 64-bit
    */
   bool is_64bit() const
   {
      return glsl_base_type_is_64bit(base_type);
   }

   /**
    * Query whether or not a type is a non-array boolean type
    */
   bool is_boolean() const
   {
      return base_type == GLSL_TYPE_BOOL;
   }

   /**
    * Query whether or not a type is a sampler
    */
   bool is_sampler() const
   {
      return base_type == GLSL_TYPE_SAMPLER;
   }

   /**
    * Query whether or not type is a sampler, or for struct, interface and
    * array types, contains a sampler.
    */
   bool contains_sampler() const;

   /**
    * Get the Mesa texture target index for a sampler type.
    */
   gl_texture_index sampler_index() const;

   /**
    * Query whether or not type is an image, or for struct, interface and
    * array types, contains an image.
    */
   bool contains_image() const;

   /**
    * Query whether or not a type is an image
    */
   bool is_image() const
   {
      return base_type == GLSL_TYPE_IMAGE;
   }

   /**
    * Query whether or not a type is an array
    */
   bool is_array() const
   {
      return base_type == GLSL_TYPE_ARRAY;
   }

   bool is_array_of_arrays() const
   {
      return is_array() && fields.array->is_array();
   }

   /**
    * Query whether or not a type is a record
    */
   bool is_record() const
   {
      return base_type == GLSL_TYPE_STRUCT;
   }

   /**
    * Query whether or not a type is an interface
    */
   bool is_interface() const
   {
      return base_type == GLSL_TYPE_INTERFACE;
   }

   /**
    * Query whether or not a type is the void type singleton.
    */
   bool is_void() const
   {
      return base_type == GLSL_TYPE_VOID;
   }

   /**
    * Query whether or not a type is the error type singleton.
    */
   bool is_error() const
   {
      return base_type == GLSL_TYPE_ERROR;
   }

   /**
    * Query if a type is unnamed/anonymous (named by the parser)
    */

   bool is_subroutine() const
   {
      return base_type == GLSL_TYPE_SUBROUTINE;
   }
   bool contains_subroutine() const;

   bool is_anonymous() const
   {
      return !strncmp(name, "#anon", 5);
   }

   /**
    * Get the type stripped of any arrays
    *
    * \return
    * Pointer to the type of elements of the first non-array type for array
    * types, or pointer to itself for non-array types.
    */
   const glsl_type *without_array() const
   {
      const glsl_type *t = this;

      while (t->is_array())
         t = t->fields.array;

      return t;
   }

   /**
    * Return the total number of elements in an array including the elements
    * in arrays of arrays.
    */
   unsigned arrays_of_arrays_size() const
   {
      if (!is_array())
         return 0;

      unsigned size = length;
      const glsl_type *base_type = fields.array;

      while (base_type->is_array()) {
         size = size * base_type->length;
         base_type = base_type->fields.array;
      }
      return size;
   }

   /**
    * Query whether or not a type is an atomic_uint.
    */
   bool is_atomic_uint() const
   {
      return base_type == GLSL_TYPE_ATOMIC_UINT;
   }

   /**
    * Return the amount of atomic counter storage required for a type.
    */
   unsigned atomic_size() const
   {
      if (is_atomic_uint())
         return ATOMIC_COUNTER_SIZE;
      else if (is_array())
         return length * fields.array->atomic_size();
      else
         return 0;
   }

   /**
    * Return whether a type contains any atomic counters.
    */
   bool contains_atomic() const
   {
      return atomic_size() > 0;
   }

   /**
    * Return whether a type contains any opaque types.
    */
   bool contains_opaque() const;

   /**
    * Query the full type of a matrix row
    *
    * \return
    * If the type is not a matrix, \c glsl_type::error_type is returned.
    * Otherwise a type matching the rows of the matrix is returned.
    */
   const glsl_type *row_type() const
   {
      return is_matrix()
         ? get_instance(base_type, matrix_columns, 1)
         : error_type;
   }

   /**
    * Query the full type of a matrix column
    *
    * \return
    * If the type is not a matrix, \c glsl_type::error_type is returned.
    * Otherwise a type matching the columns of the matrix is returned.
    */
   const glsl_type *column_type() const
   {
      return is_matrix()
         ? get_instance(base_type, vector_elements, 1)
         : error_type;
   }

   /**
    * Get the type of a structure field
    *
    * \return
    * Pointer to the type of the named field.  If the type is not a structure
    * or the named field does not exist, \c glsl_type::error_type is returned.
    */
   const glsl_type *field_type(const char *name) const;

   /**
    * Get the location of a field within a record type
    */
   int field_index(const char *name) const;

   /**
    * Query the number of elements in an array type
    *
    * \return
    * The number of elements in the array for array types or -1 for non-array
    * types.  If the number of elements in the array has not yet been declared,
    * zero is returned.
    */
   int array_size() const
   {
      return is_array() ? length : -1;
   }

   /**
    * Query whether the array size for all dimensions has been declared.
    */
   bool is_unsized_array() const
   {
      return is_array() && length == 0;
   }

   /**
    * Return the number of coordinate components needed for this
    * sampler or image type.
    *
    * This is based purely on the sampler's dimensionality.  For example, this
    * returns 1 for sampler1D, and 3 for sampler2DArray.
    *
    * Note that this is often different than actual coordinate type used in
    * a texturing built-in function, since those pack additional values (such
    * as the shadow comparator or projector) into the coordinate type.
    */
   int coordinate_components() const;

   /**
    * Compare a record type against another record type.
    *
    * This is useful for matching record types declared across shader stages.
    * The option to not match locations is to deal with places where the
    * same struct is defined in a block which has a location set on it.
    */
   bool record_compare(const glsl_type *b, bool match_locations = true) const;

   /**
    * Get the type interface packing.
    */
   enum glsl_interface_packing get_interface_packing() const
   {
      return (enum glsl_interface_packing)interface_packing;
   }

   /**
    * Check if the type interface is row major
    */
   bool get_interface_row_major() const
   {
      return (bool) interface_row_major;
   }

private:

   static mtx_t mutex;

   /**
    * ralloc context for all glsl_type allocations
    *
    * Set on the first call to \c glsl_type::new.
    */
   static void *mem_ctx;

   void init_ralloc_type_ctx(void);

   /** Constructor for vector and matrix types */
   glsl_type(GLenum gl_type,
             glsl_base_type base_type, unsigned vector_elements,
             unsigned matrix_columns, const char *name);

   /** Constructor for sampler or image types */
   glsl_type(GLenum gl_type, glsl_base_type base_type,
             enum glsl_sampler_dim dim, bool shadow, bool array,
             unsigned type, const char *name);

   /** Constructor for record types */
   glsl_type(const glsl_struct_field *fields, unsigned num_fields,
             const char *name);

   /** Constructor for interface types */
   glsl_type(const glsl_struct_field *fields, unsigned num_fields,
             enum glsl_interface_packing packing,
             bool row_major, const char *name);

   /** Constructor for interface types */
   glsl_type(const glsl_type *return_type,
             const glsl_function_param *params, unsigned num_params);

   /** Constructor for array types */
   glsl_type(const glsl_type *array, unsigned length);

   /** Constructor for subroutine types */
   glsl_type(const char *name);

   /** Hash table containing the known array types. */
   static struct hash_table *array_types;

   /** Hash table containing the known record types. */
   static struct hash_table *record_types;

   /** Hash table containing the known interface types. */
   static struct hash_table *interface_types;

   /** Hash table containing the known subroutine types. */
   static struct hash_table *subroutine_types;

   /** Hash table containing the known function types. */
   static struct hash_table *function_types;

   static bool record_key_compare(const void *a, const void *b);
   static unsigned record_key_hash(const void *key);

   /**
    * \name Built-in type flyweights
    */
   /*@{*/
#undef  DECL_TYPE
#define DECL_TYPE(NAME, ...) static const glsl_type _##NAME##_type;
#undef  STRUCT_TYPE
#define STRUCT_TYPE(NAME)        static const glsl_type _struct_##NAME##_type;
#include "compiler/builtin_type_macros.h"
   /*@}*/

   /**
    * \name Friend functions.
    *
    * These functions are friends because they must have C linkage and the
    * need to call various private methods or access various private static
    * data.
    */
   /*@{*/
   friend void _mesa_glsl_initialize_types(struct _mesa_glsl_parse_state *);
   friend void _mesa_glsl_release_types(void);
   /*@}*/
};

#undef DECL_TYPE
#undef STRUCT_TYPE
#endif /* __cplusplus */

struct glsl_struct_field {
   const struct glsl_type *type;
   const char *name;

   /**
    * For interface blocks, gl_varying_slot corresponding to the input/output
    * if this is a built-in input/output (i.e. a member of the built-in
    * gl_PerVertex interface block); -1 otherwise.
    *
    * Ignored for structs.
    */
   int location;

   /**
    * For interface blocks, members may have an explicit byte offset
    * specified; -1 otherwise. Also used for xfb_offset layout qualifier.
    *
    * Unless used for xfb_offset this field is ignored for structs.
    */
   int offset;

   /**
    * For interface blocks, members may define a transform feedback buffer;
    * -1 otherwise.
    */
   int xfb_buffer;

   /**
    * For interface blocks, members may define a transform feedback stride;
    * -1 otherwise.
    */
   int xfb_stride;

   /**
    * For interface blocks, the interpolation mode (as in
    * ir_variable::interpolation).  0 otherwise.
    */
   unsigned interpolation:2;

   /**
    * For interface blocks, 1 if this variable uses centroid interpolation (as
    * in ir_variable::centroid).  0 otherwise.
    */
   unsigned centroid:1;

   /**
    * For interface blocks, 1 if this variable uses sample interpolation (as
    * in ir_variable::sample). 0 otherwise.
    */
   unsigned sample:1;

   /**
    * Layout of the matrix.  Uses glsl_matrix_layout values.
    */
   unsigned matrix_layout:2;

   /**
    * For interface blocks, 1 if this variable is a per-patch input or output
    * (as in ir_variable::patch). 0 otherwise.
    */
   unsigned patch:1;

   /**
    * Precision qualifier
    */
   unsigned precision:2;

   /**
    * Memory qualifiers, applicable to buffer variables defined in shader
    * storage buffer objects (SSBOs)
    */
   unsigned memory_read_only:1;
   unsigned memory_write_only:1;
   unsigned memory_coherent:1;
   unsigned memory_volatile:1;
   unsigned memory_restrict:1;

   /**
    * Any of the xfb_* qualifiers trigger the shader to be in transform
    * feedback mode so we need to keep track of whether the buffer was
    * explicitly set or if its just been assigned the default global value.
    */
   unsigned explicit_xfb_buffer:1;

   unsigned implicit_sized_array:1;
#ifdef __cplusplus
   glsl_struct_field(const struct glsl_type *_type, const char *_name)
      : type(_type), name(_name), location(-1), offset(0), xfb_buffer(0),
        xfb_stride(0), interpolation(0), centroid(0),
        sample(0), matrix_layout(GLSL_MATRIX_LAYOUT_INHERITED), patch(0),
        precision(GLSL_PRECISION_NONE), memory_read_only(0),
        memory_write_only(0), memory_coherent(0), memory_volatile(0),
        memory_restrict(0), explicit_xfb_buffer(0), implicit_sized_array(0)
   {
      /* empty */
   }

   glsl_struct_field()
   {
      /* empty */
   }
#endif
};

struct glsl_function_param {
   const struct glsl_type *type;

   bool in;
   bool out;
};

static inline unsigned int
glsl_align(unsigned int a, unsigned int align)
{
   return (a + align - 1) / align * align;
}

#endif /* GLSL_TYPES_H */