/*
* 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.
*/
#pragma once
#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"
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, struct gl_shader_program *prog,
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,
const unsigned max_outputs) const;
const tfeedback_candidate *find_candidate(gl_shader_program *prog,
hash_table *tfeedback_candidates);
bool is_next_buffer_separator() const
{
return this->next_buffer_separator;
}
bool is_varying() const
{
return !this->next_buffer_separator && !this->skip_components;
}
/**
* 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->is_clip_distance_mesa)
return this->size;
else
return this->vector_elements * this->matrix_columns * this->size;
}
unsigned get_location() const {
return this->location;
}
private:
/**
* 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;
/**
* True if the variable is gl_ClipDistance and the driver lowers
* gl_ClipDistance to gl_ClipDistanceMESA.
*/
bool is_clip_distance_mesa;
/**
* The vertex shader output location that the linker assigned for this
* variable. -1 if a location hasn't been assigned yet.
*/
int location;
/**
* 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;
};
bool
cross_validate_outputs_to_inputs(struct gl_shader_program *prog,
gl_shader *producer, gl_shader *consumer);
bool
parse_tfeedback_decls(struct gl_context *ctx, struct gl_shader_program *prog,
const void *mem_ctx, unsigned num_names,
char **varying_names, tfeedback_decl *decls);
bool
store_tfeedback_info(struct gl_context *ctx, struct gl_shader_program *prog,
unsigned num_tfeedback_decls,
tfeedback_decl *tfeedback_decls);
bool
assign_varying_locations(struct gl_context *ctx,
void *mem_ctx,
struct gl_shader_program *prog,
gl_shader *producer, gl_shader *consumer,
unsigned num_tfeedback_decls,
tfeedback_decl *tfeedback_decls);
bool
check_against_varying_limit(struct gl_context *ctx,
struct gl_shader_program *prog,
gl_shader *consumer);
#endif /* GLSL_LINK_VARYINGS_H */