/*
* Mesa 3-D graphics library
*
* Copyright (C) 1999-2008 Brian Paul All Rights Reserved.
* Copyright (C) 2009 VMware, Inc. All Rights Reserved.
*
* 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 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 SHADER_ENUMS_H
#define SHADER_ENUMS_H
/**
* Shader stages. Note that these will become 5 with tessellation.
*
* The order must match how shaders are ordered in the pipeline.
* The GLSL linker assumes that if i<j, then the j-th shader is
* executed later than the i-th shader.
*/
typedef enum
{
MESA_SHADER_VERTEX = 0,
MESA_SHADER_GEOMETRY = 1,
MESA_SHADER_FRAGMENT = 2,
MESA_SHADER_COMPUTE = 3,
} gl_shader_stage;
#define MESA_SHADER_STAGES (MESA_SHADER_COMPUTE + 1)
/**
* Bitflags for system values.
*/
#define SYSTEM_BIT_SAMPLE_ID ((uint64_t)1 << SYSTEM_VALUE_SAMPLE_ID)
#define SYSTEM_BIT_SAMPLE_POS ((uint64_t)1 << SYSTEM_VALUE_SAMPLE_POS)
#define SYSTEM_BIT_SAMPLE_MASK_IN ((uint64_t)1 << SYSTEM_VALUE_SAMPLE_MASK_IN)
/**
* If the gl_register_file is PROGRAM_SYSTEM_VALUE, the register index will be
* one of these values. If a NIR variable's mode is nir_var_system_value, it
* will be one of these values.
*/
typedef enum
{
/**
* \name Vertex shader system values
*/
/*@{*/
/**
* OpenGL-style vertex ID.
*
* Section 2.11.7 (Shader Execution), subsection Shader Inputs, of the
* OpenGL 3.3 core profile spec says:
*
* "gl_VertexID holds the integer index i implicitly passed by
* DrawArrays or one of the other drawing commands defined in section
* 2.8.3."
*
* Section 2.8.3 (Drawing Commands) of the same spec says:
*
* "The commands....are equivalent to the commands with the same base
* name (without the BaseVertex suffix), except that the ith element
* transferred by the corresponding draw call will be taken from
* element indices[i] + basevertex of each enabled array."
*
* Additionally, the overview in the GL_ARB_shader_draw_parameters spec
* says:
*
* "In unextended GL, vertex shaders have inputs named gl_VertexID and
* gl_InstanceID, which contain, respectively the index of the vertex
* and instance. The value of gl_VertexID is the implicitly passed
* index of the vertex being processed, which includes the value of
* baseVertex, for those commands that accept it."
*
* gl_VertexID gets basevertex added in. This differs from DirectX where
* SV_VertexID does \b not get basevertex added in.
*
* \note
* If all system values are available, \c SYSTEM_VALUE_VERTEX_ID will be
* equal to \c SYSTEM_VALUE_VERTEX_ID_ZERO_BASE plus
* \c SYSTEM_VALUE_BASE_VERTEX.
*
* \sa SYSTEM_VALUE_VERTEX_ID_ZERO_BASE, SYSTEM_VALUE_BASE_VERTEX
*/
SYSTEM_VALUE_VERTEX_ID,
/**
* Instanced ID as supplied to gl_InstanceID
*
* Values assigned to gl_InstanceID always begin with zero, regardless of
* the value of baseinstance.
*
* Section 11.1.3.9 (Shader Inputs) of the OpenGL 4.4 core profile spec
* says:
*
* "gl_InstanceID holds the integer instance number of the current
* primitive in an instanced draw call (see section 10.5)."
*
* Through a big chain of pseudocode, section 10.5 describes that
* baseinstance is not counted by gl_InstanceID. In that section, notice
*
* "If an enabled vertex attribute array is instanced (it has a
* non-zero divisor as specified by VertexAttribDivisor), the element
* index that is transferred to the GL, for all vertices, is given by
*
* floor(instance/divisor) + baseinstance
*
* If an array corresponding to an attribute required by a vertex
* shader is not enabled, then the corresponding element is taken from
* the current attribute state (see section 10.2)."
*
* Note that baseinstance is \b not included in the value of instance.
*/
SYSTEM_VALUE_INSTANCE_ID,
/**
* DirectX-style vertex ID.
*
* Unlike \c SYSTEM_VALUE_VERTEX_ID, this system value does \b not include
* the value of basevertex.
*
* \sa SYSTEM_VALUE_VERTEX_ID, SYSTEM_VALUE_BASE_VERTEX
*/
SYSTEM_VALUE_VERTEX_ID_ZERO_BASE,
/**
* Value of \c basevertex passed to \c glDrawElementsBaseVertex and similar
* functions.
*
* \sa SYSTEM_VALUE_VERTEX_ID, SYSTEM_VALUE_VERTEX_ID_ZERO_BASE
*/
SYSTEM_VALUE_BASE_VERTEX,
/*@}*/
/**
* \name Geometry shader system values
*/
/*@{*/
SYSTEM_VALUE_INVOCATION_ID,
/*@}*/
/**
* \name Fragment shader system values
*/
/*@{*/
SYSTEM_VALUE_FRONT_FACE, /**< (not done yet) */
SYSTEM_VALUE_SAMPLE_ID,
SYSTEM_VALUE_SAMPLE_POS,
SYSTEM_VALUE_SAMPLE_MASK_IN,
/*@}*/
SYSTEM_VALUE_MAX /**< Number of values */
} gl_system_value;
/**
* The possible interpolation qualifiers that can be applied to a fragment
* shader input in GLSL.
*
* Note: INTERP_QUALIFIER_NONE must be 0 so that memsetting the
* gl_fragment_program data structure to 0 causes the default behavior.
*/
enum glsl_interp_qualifier
{
INTERP_QUALIFIER_NONE = 0,
INTERP_QUALIFIER_SMOOTH,
INTERP_QUALIFIER_FLAT,
INTERP_QUALIFIER_NOPERSPECTIVE,
INTERP_QUALIFIER_COUNT /**< Number of interpolation qualifiers */
};
#endif /* SHADER_ENUMS_H */