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/*
* Copyright © 2012 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_LINK_VARYINGS_H
#define GLSL_LINK_VARYINGS_H
/**
* \file link_varyings.h
*
* Linker functions related specifically to linking varyings between shader
* stages.
*/
#include "main/glheader.h"
#include "program/prog_parameter.h"
#include "util/bitset.h"
struct gl_shader_program;
struct gl_shader;
class ir_variable;
/**
* Data structure describing a varying which is available for use in transform
* feedback.
*
* For example, if the vertex shader contains:
*
* struct S {
* vec4 foo;
* float[3] bar;
* };
*
* varying S[2] v;
*
* Then there would be tfeedback_candidate objects corresponding to the
* following varyings:
*
* v[0].foo
* v[0].bar
* v[1].foo
* v[1].bar
*/
struct tfeedback_candidate
{
/**
* Toplevel variable containing this varying. In the above example, this
* would point to the declaration of the varying v.
*/
ir_variable *toplevel_var;
/**
* Type of this varying. In the above example, this would point to the
* glsl_type for "vec4" or "float[3]".
*/
const glsl_type *type;
/**
* Offset within the toplevel variable where this varying occurs (counted
* in multiples of the size of a float).
*/
unsigned offset;
};
/**
* Data structure tracking information about a transform feedback declaration
* during linking.
*/
class tfeedback_decl
{
public:
void init(struct gl_context *ctx, const void *mem_ctx, const char *input);
static bool is_same(const tfeedback_decl &x, const tfeedback_decl &y);
bool assign_location(struct gl_context *ctx,
struct gl_shader_program *prog);
unsigned get_num_outputs() const;
bool store(struct gl_context *ctx, struct gl_shader_program *prog,
struct gl_transform_feedback_info *info, unsigned buffer,
unsigned buffer_index, const unsigned max_outputs,
BITSET_WORD *used_components[MAX_FEEDBACK_BUFFERS],
bool *explicit_stride, bool has_xfb_qualifiers,
const void *mem_ctx) const;
const tfeedback_candidate *find_candidate(gl_shader_program *prog,
hash_table *tfeedback_candidates);
void set_lowered_candidate(const tfeedback_candidate *candidate);
bool is_next_buffer_separator() const
{
return this->next_buffer_separator;
}
bool is_varying_written() const
{
if (this->next_buffer_separator || this->skip_components)
return false;
return this->matched_candidate->toplevel_var->data.assigned;
}
bool is_varying() const
{
return !this->next_buffer_separator && !this->skip_components;
}
bool is_aligned(unsigned dmul, unsigned offset) const
{
return (dmul * (this->array_subscript + offset)) % 4 == 0;
}
const char *name() const
{
return this->orig_name;
}
unsigned get_stream_id() const
{
return this->stream_id;
}
unsigned get_buffer() const
{
return this->buffer;
}
unsigned get_offset() const
{
return this->offset;
}
/**
* The total number of varying components taken up by this variable. Only
* valid if assign_location() has been called.
*/
unsigned num_components() const
{
if (this->lowered_builtin_array_variable)
return this->size;
else
return this->vector_elements * this->matrix_columns * this->size *
(this->is_64bit() ? 2 : 1);
}
unsigned get_location() const {
return this->location;
}
private:
bool is_64bit() const
{
return _mesa_gl_datatype_is_64bit(this->type);
}
/**
* The name that was supplied to glTransformFeedbackVaryings. Used for
* error reporting and glGetTransformFeedbackVarying().
*/
const char *orig_name;
/**
* The name of the variable, parsed from orig_name.
*/
const char *var_name;
/**
* True if the declaration in orig_name represents an array.
*/
bool is_subscripted;
/**
* If is_subscripted is true, the subscript that was specified in orig_name.
*/
unsigned array_subscript;
/**
* Non-zero if the variable is gl_ClipDistance, glTessLevelOuter or
* gl_TessLevelInner and the driver lowers it to gl_*MESA.
*/
enum {
none,
clip_distance,
cull_distance,
tess_level_outer,
tess_level_inner,
} lowered_builtin_array_variable;
/**
* The vertex shader output location that the linker assigned for this
* variable. -1 if a location hasn't been assigned yet.
*/
int location;
/**
* Used to store the buffer assigned by xfb_buffer.
*/
unsigned buffer;
/**
* Used to store the offset assigned by xfb_offset.
*/
unsigned offset;
/**
* If non-zero, then this variable may be packed along with other variables
* into a single varying slot, so this offset should be applied when
* accessing components. For example, an offset of 1 means that the x
* component of this variable is actually stored in component y of the
* location specified by \c location.
*
* Only valid if location != -1.
*/
unsigned location_frac;
/**
* If location != -1, the number of vector elements in this variable, or 1
* if this variable is a scalar.
*/
unsigned vector_elements;
/**
* If location != -1, the number of matrix columns in this variable, or 1
* if this variable is not a matrix.
*/
unsigned matrix_columns;
/** Type of the varying returned by glGetTransformFeedbackVarying() */
GLenum type;
/**
* If location != -1, the size that should be returned by
* glGetTransformFeedbackVarying().
*/
unsigned size;
/**
* How many components to skip. If non-zero, this is
* gl_SkipComponents{1,2,3,4} from ARB_transform_feedback3.
*/
unsigned skip_components;
/**
* Whether this is gl_NextBuffer from ARB_transform_feedback3.
*/
bool next_buffer_separator;
/**
* If find_candidate() has been called, pointer to the tfeedback_candidate
* data structure that was found. Otherwise NULL.
*/
const tfeedback_candidate *matched_candidate;
/**
* StreamId assigned to this varying (defaults to 0). Can only be set to
* values other than 0 in geometry shaders that use the stream layout
* modifier. Accepted values must be in the range [0, MAX_VERTEX_STREAMS-1].
*/
unsigned stream_id;
};
bool
link_varyings(struct gl_shader_program *prog, unsigned first, unsigned last,
struct gl_context *ctx, void *mem_ctx);
void
validate_first_and_last_interface_explicit_locations(struct gl_context *ctx,
struct gl_shader_program *prog,
gl_shader_stage first,
gl_shader_stage last);
void
cross_validate_outputs_to_inputs(struct gl_context *ctx,
struct gl_shader_program *prog,
gl_linked_shader *producer,
gl_linked_shader *consumer);
#endif /* GLSL_LINK_VARYINGS_H */