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24 #ifndef GLSL_LINK_VARYINGS_H
25 #define GLSL_LINK_VARYINGS_H
28 * \file link_varyings.h
30 * Linker functions related specifically to linking varyings between shader
35 #include "main/glheader.h"
36 #include "program/prog_parameter.h"
37 #include "util/bitset.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 unsigned buffer_index
, const unsigned max_outputs
,
102 BITSET_WORD
*used_components
[MAX_FEEDBACK_BUFFERS
],
103 bool *explicit_stride
, bool has_xfb_qualifiers
,
104 const void *mem_ctx
) const;
105 const tfeedback_candidate
*find_candidate(gl_shader_program
*prog
,
106 hash_table
*tfeedback_candidates
);
107 void set_lowered_candidate(const tfeedback_candidate
*candidate
);
109 bool is_next_buffer_separator() const
111 return this->next_buffer_separator
;
114 bool is_varying_written() const
116 if (this->next_buffer_separator
|| this->skip_components
)
119 return this->matched_candidate
->toplevel_var
->data
.assigned
;
122 bool is_varying() const
124 return !this->next_buffer_separator
&& !this->skip_components
;
127 bool is_aligned(unsigned dmul
, unsigned offset
) const
129 return (dmul
* (this->array_subscript
+ offset
)) % 4 == 0;
132 const char *name() const
134 return this->orig_name
;
137 unsigned get_stream_id() const
139 return this->stream_id
;
142 unsigned get_buffer() const
147 unsigned get_offset() const
153 * The total number of varying components taken up by this variable. Only
154 * valid if assign_location() has been called.
156 unsigned num_components() const
158 if (this->lowered_builtin_array_variable
)
161 return this->vector_elements
* this->matrix_columns
* this->size
*
162 (this->is_64bit() ? 2 : 1);
165 unsigned get_location() const {
166 return this->location
;
171 bool is_64bit() const
173 return _mesa_gl_datatype_is_64bit(this->type
);
177 * The name that was supplied to glTransformFeedbackVaryings. Used for
178 * error reporting and glGetTransformFeedbackVarying().
180 const char *orig_name
;
183 * The name of the variable, parsed from orig_name.
185 const char *var_name
;
188 * True if the declaration in orig_name represents an array.
193 * If is_subscripted is true, the subscript that was specified in orig_name.
195 unsigned array_subscript
;
198 * Non-zero if the variable is gl_ClipDistance, glTessLevelOuter or
199 * gl_TessLevelInner and the driver lowers it to gl_*MESA.
207 } lowered_builtin_array_variable
;
210 * The vertex shader output location that the linker assigned for this
211 * variable. -1 if a location hasn't been assigned yet.
216 * Used to store the buffer assigned by xfb_buffer.
221 * Used to store the offset assigned by xfb_offset.
226 * If non-zero, then this variable may be packed along with other variables
227 * into a single varying slot, so this offset should be applied when
228 * accessing components. For example, an offset of 1 means that the x
229 * component of this variable is actually stored in component y of the
230 * location specified by \c location.
232 * Only valid if location != -1.
234 unsigned location_frac
;
237 * If location != -1, the number of vector elements in this variable, or 1
238 * if this variable is a scalar.
240 unsigned vector_elements
;
243 * If location != -1, the number of matrix columns in this variable, or 1
244 * if this variable is not a matrix.
246 unsigned matrix_columns
;
248 /** Type of the varying returned by glGetTransformFeedbackVarying() */
252 * If location != -1, the size that should be returned by
253 * glGetTransformFeedbackVarying().
258 * How many components to skip. If non-zero, this is
259 * gl_SkipComponents{1,2,3,4} from ARB_transform_feedback3.
261 unsigned skip_components
;
264 * Whether this is gl_NextBuffer from ARB_transform_feedback3.
266 bool next_buffer_separator
;
269 * If find_candidate() has been called, pointer to the tfeedback_candidate
270 * data structure that was found. Otherwise NULL.
272 const tfeedback_candidate
*matched_candidate
;
275 * StreamId assigned to this varying (defaults to 0). Can only be set to
276 * values other than 0 in geometry shaders that use the stream layout
277 * modifier. Accepted values must be in the range [0, MAX_VERTEX_STREAMS-1].
283 link_varyings(struct gl_shader_program
*prog
, unsigned first
, unsigned last
,
284 struct gl_context
*ctx
, void *mem_ctx
);
287 validate_first_and_last_interface_explicit_locations(struct gl_context
*ctx
,
288 struct gl_shader_program
*prog
,
289 gl_shader_stage first
,
290 gl_shader_stage last
);
293 cross_validate_outputs_to_inputs(struct gl_context
*ctx
,
294 struct gl_shader_program
*prog
,
295 gl_linked_shader
*producer
,
296 gl_linked_shader
*consumer
);
298 #endif /* GLSL_LINK_VARYINGS_H */