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25 #ifndef GLSL_LINK_VARYINGS_H
26 #define GLSL_LINK_VARYINGS_H
29 * \file link_varyings.h
31 * Linker functions related specifically to linking varyings between shader
36 #include "main/glheader.h"
39 struct gl_shader_program
;
45 * Data structure describing a varying which is available for use in transform
48 * For example, if the vertex shader contains:
57 * Then there would be tfeedback_candidate objects corresponding to the
65 struct tfeedback_candidate
68 * Toplevel variable containing this varying. In the above example, this
69 * would point to the declaration of the varying v.
71 ir_variable
*toplevel_var
;
74 * Type of this varying. In the above example, this would point to the
75 * glsl_type for "vec4" or "float[3]".
77 const glsl_type
*type
;
80 * Offset within the toplevel variable where this varying occurs (counted
81 * in multiples of the size of a float).
88 * Data structure tracking information about a transform feedback declaration
94 void init(struct gl_context
*ctx
, const void *mem_ctx
, const char *input
);
95 static bool is_same(const tfeedback_decl
&x
, const tfeedback_decl
&y
);
96 bool assign_location(struct gl_context
*ctx
,
97 struct gl_shader_program
*prog
);
98 unsigned get_num_outputs() const;
99 bool store(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
100 struct gl_transform_feedback_info
*info
, unsigned buffer
,
101 const unsigned max_outputs
) const;
102 const tfeedback_candidate
*find_candidate(gl_shader_program
*prog
,
103 hash_table
*tfeedback_candidates
);
105 bool is_next_buffer_separator() const
107 return this->next_buffer_separator
;
110 bool is_varying() const
112 return !this->next_buffer_separator
&& !this->skip_components
;
116 * The total number of varying components taken up by this variable. Only
117 * valid if assign_location() has been called.
119 unsigned num_components() const
121 if (this->is_clip_distance_mesa
)
124 return this->vector_elements
* this->matrix_columns
* this->size
;
127 unsigned get_location() const {
128 return this->location
;
133 * The name that was supplied to glTransformFeedbackVaryings. Used for
134 * error reporting and glGetTransformFeedbackVarying().
136 const char *orig_name
;
139 * The name of the variable, parsed from orig_name.
141 const char *var_name
;
144 * True if the declaration in orig_name represents an array.
149 * If is_subscripted is true, the subscript that was specified in orig_name.
151 unsigned array_subscript
;
154 * True if the variable is gl_ClipDistance and the driver lowers
155 * gl_ClipDistance to gl_ClipDistanceMESA.
157 bool is_clip_distance_mesa
;
160 * The vertex shader output location that the linker assigned for this
161 * variable. -1 if a location hasn't been assigned yet.
166 * If non-zero, then this variable may be packed along with other variables
167 * into a single varying slot, so this offset should be applied when
168 * accessing components. For example, an offset of 1 means that the x
169 * component of this variable is actually stored in component y of the
170 * location specified by \c location.
172 * Only valid if location != -1.
174 unsigned location_frac
;
177 * If location != -1, the number of vector elements in this variable, or 1
178 * if this variable is a scalar.
180 unsigned vector_elements
;
183 * If location != -1, the number of matrix columns in this variable, or 1
184 * if this variable is not a matrix.
186 unsigned matrix_columns
;
188 /** Type of the varying returned by glGetTransformFeedbackVarying() */
192 * If location != -1, the size that should be returned by
193 * glGetTransformFeedbackVarying().
198 * How many components to skip. If non-zero, this is
199 * gl_SkipComponents{1,2,3,4} from ARB_transform_feedback3.
201 unsigned skip_components
;
204 * Whether this is gl_NextBuffer from ARB_transform_feedback3.
206 bool next_buffer_separator
;
209 * If find_candidate() has been called, pointer to the tfeedback_candidate
210 * data structure that was found. Otherwise NULL.
212 const tfeedback_candidate
*matched_candidate
;
217 cross_validate_outputs_to_inputs(struct gl_shader_program
*prog
,
218 gl_shader
*producer
, gl_shader
*consumer
);
221 parse_tfeedback_decls(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
222 const void *mem_ctx
, unsigned num_names
,
223 char **varying_names
, tfeedback_decl
*decls
);
226 store_tfeedback_info(struct gl_context
*ctx
, struct gl_shader_program
*prog
,
227 unsigned num_tfeedback_decls
,
228 tfeedback_decl
*tfeedback_decls
);
231 assign_varying_locations(struct gl_context
*ctx
,
233 struct gl_shader_program
*prog
,
234 gl_shader
*producer
, gl_shader
*consumer
,
235 unsigned num_tfeedback_decls
,
236 tfeedback_decl
*tfeedback_decls
,
237 unsigned gs_input_vertices
);
240 check_against_varying_limit(struct gl_context
*ctx
,
241 struct gl_shader_program
*prog
,
242 gl_shader
*consumer
);
244 #endif /* GLSL_LINK_VARYINGS_H */