src/glsl/shader_enums.h

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   5  * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  21  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  22  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  23  * OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26 #ifndef SHADER_ENUMS_H
  27 #define SHADER_ENUMS_H
  28
  29 /**
  30  * Shader stages. Note that these will become 5 with tessellation.
  31  *
  32  * The order must match how shaders are ordered in the pipeline.
  33  * The GLSL linker assumes that if i<j, then the j-th shader is
  34  * executed later than the i-th shader.
  35  */
  36 typedef enum
  37 {
  38    MESA_SHADER_VERTEX = 0,
  39    MESA_SHADER_TESS_CTRL = 1,
  40    MESA_SHADER_TESS_EVAL = 2,
  41    MESA_SHADER_GEOMETRY = 3,
  42    MESA_SHADER_FRAGMENT = 4,
  43    MESA_SHADER_COMPUTE = 5,
  44 } gl_shader_stage;
  45
  46 #define MESA_SHADER_STAGES (MESA_SHADER_COMPUTE + 1)
  47
  48 /**
  49  * Indexes for vertex shader outputs, geometry shader inputs/outputs, and
  50  * fragment shader inputs.
  51  *
  52  * Note that some of these values are not available to all pipeline stages.
  53  *
  54  * When this enum is updated, the following code must be updated too:
  55  * - vertResults (in prog_print.c's arb_output_attrib_string())
  56  * - fragAttribs (in prog_print.c's arb_input_attrib_string())
  57  * - _mesa_varying_slot_in_fs()
  58  */
  59 typedef enum
  60 {
  61    VARYING_SLOT_POS,
  62    VARYING_SLOT_COL0, /* COL0 and COL1 must be contiguous */
  63    VARYING_SLOT_COL1,
  64    VARYING_SLOT_FOGC,
  65    VARYING_SLOT_TEX0, /* TEX0-TEX7 must be contiguous */
  66    VARYING_SLOT_TEX1,
  67    VARYING_SLOT_TEX2,
  68    VARYING_SLOT_TEX3,
  69    VARYING_SLOT_TEX4,
  70    VARYING_SLOT_TEX5,
  71    VARYING_SLOT_TEX6,
  72    VARYING_SLOT_TEX7,
  73    VARYING_SLOT_PSIZ, /* Does not appear in FS */
  74    VARYING_SLOT_BFC0, /* Does not appear in FS */
  75    VARYING_SLOT_BFC1, /* Does not appear in FS */
  76    VARYING_SLOT_EDGE, /* Does not appear in FS */
  77    VARYING_SLOT_CLIP_VERTEX, /* Does not appear in FS */
  78    VARYING_SLOT_CLIP_DIST0,
  79    VARYING_SLOT_CLIP_DIST1,
  80    VARYING_SLOT_PRIMITIVE_ID, /* Does not appear in VS */
  81    VARYING_SLOT_LAYER, /* Appears as VS or GS output */
  82    VARYING_SLOT_VIEWPORT, /* Appears as VS or GS output */
  83    VARYING_SLOT_FACE, /* FS only */
  84    VARYING_SLOT_PNTC, /* FS only */
  85    VARYING_SLOT_TESS_LEVEL_OUTER, /* Only appears as TCS output. */
  86    VARYING_SLOT_TESS_LEVEL_INNER, /* Only appears as TCS output. */
  87    VARYING_SLOT_VAR0, /* First generic varying slot */
  88 } gl_varying_slot;
  89
  90
  91 /**
  92  * Bitflags for varying slots.
  93  */
  94 /*@{*/
  95 #define VARYING_BIT_POS BITFIELD64_BIT(VARYING_SLOT_POS)
  96 #define VARYING_BIT_COL0 BITFIELD64_BIT(VARYING_SLOT_COL0)
  97 #define VARYING_BIT_COL1 BITFIELD64_BIT(VARYING_SLOT_COL1)
  98 #define VARYING_BIT_FOGC BITFIELD64_BIT(VARYING_SLOT_FOGC)
  99 #define VARYING_BIT_TEX0 BITFIELD64_BIT(VARYING_SLOT_TEX0)
 100 #define VARYING_BIT_TEX1 BITFIELD64_BIT(VARYING_SLOT_TEX1)
 101 #define VARYING_BIT_TEX2 BITFIELD64_BIT(VARYING_SLOT_TEX2)
 102 #define VARYING_BIT_TEX3 BITFIELD64_BIT(VARYING_SLOT_TEX3)
 103 #define VARYING_BIT_TEX4 BITFIELD64_BIT(VARYING_SLOT_TEX4)
 104 #define VARYING_BIT_TEX5 BITFIELD64_BIT(VARYING_SLOT_TEX5)
 105 #define VARYING_BIT_TEX6 BITFIELD64_BIT(VARYING_SLOT_TEX6)
 106 #define VARYING_BIT_TEX7 BITFIELD64_BIT(VARYING_SLOT_TEX7)
 107 #define VARYING_BIT_TEX(U) BITFIELD64_BIT(VARYING_SLOT_TEX0 + (U))
 108 #define VARYING_BITS_TEX_ANY BITFIELD64_RANGE(VARYING_SLOT_TEX0, \
 109                                               MAX_TEXTURE_COORD_UNITS)
 110 #define VARYING_BIT_PSIZ BITFIELD64_BIT(VARYING_SLOT_PSIZ)
 111 #define VARYING_BIT_BFC0 BITFIELD64_BIT(VARYING_SLOT_BFC0)
 112 #define VARYING_BIT_BFC1 BITFIELD64_BIT(VARYING_SLOT_BFC1)
 113 #define VARYING_BIT_EDGE BITFIELD64_BIT(VARYING_SLOT_EDGE)
 114 #define VARYING_BIT_CLIP_VERTEX BITFIELD64_BIT(VARYING_SLOT_CLIP_VERTEX)
 115 #define VARYING_BIT_CLIP_DIST0 BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST0)
 116 #define VARYING_BIT_CLIP_DIST1 BITFIELD64_BIT(VARYING_SLOT_CLIP_DIST1)
 117 #define VARYING_BIT_PRIMITIVE_ID BITFIELD64_BIT(VARYING_SLOT_PRIMITIVE_ID)
 118 #define VARYING_BIT_LAYER BITFIELD64_BIT(VARYING_SLOT_LAYER)
 119 #define VARYING_BIT_VIEWPORT BITFIELD64_BIT(VARYING_SLOT_VIEWPORT)
 120 #define VARYING_BIT_FACE BITFIELD64_BIT(VARYING_SLOT_FACE)
 121 #define VARYING_BIT_PNTC BITFIELD64_BIT(VARYING_SLOT_PNTC)
 122 #define VARYING_BIT_TESS_LEVEL_OUTER BITFIELD64_BIT(VARYING_SLOT_TESS_LEVEL_OUTER)
 123 #define VARYING_BIT_TESS_LEVEL_INNER BITFIELD64_BIT(VARYING_SLOT_TESS_LEVEL_INNER)
 124 #define VARYING_BIT_VAR(V) BITFIELD64_BIT(VARYING_SLOT_VAR0 + (V))
 125 /*@}*/
 126
 127 /**
 128  * Bitflags for system values.
 129  */
 130 #define SYSTEM_BIT_SAMPLE_ID ((uint64_t)1 << SYSTEM_VALUE_SAMPLE_ID)
 131 #define SYSTEM_BIT_SAMPLE_POS ((uint64_t)1 << SYSTEM_VALUE_SAMPLE_POS)
 132 #define SYSTEM_BIT_SAMPLE_MASK_IN ((uint64_t)1 << SYSTEM_VALUE_SAMPLE_MASK_IN)
 133 /**
 134  * If the gl_register_file is PROGRAM_SYSTEM_VALUE, the register index will be
 135  * one of these values.  If a NIR variable's mode is nir_var_system_value, it
 136  * will be one of these values.
 137  */
 138 typedef enum
 139 {
 140    /**
 141     * \name Vertex shader system values
 142     */
 143    /*@{*/
 144    /**
 145     * OpenGL-style vertex ID.
 146     *
 147     * Section 2.11.7 (Shader Execution), subsection Shader Inputs, of the
 148     * OpenGL 3.3 core profile spec says:
 149     *
 150     *     "gl_VertexID holds the integer index i implicitly passed by
 151     *     DrawArrays or one of the other drawing commands defined in section
 152     *     2.8.3."
 153     *
 154     * Section 2.8.3 (Drawing Commands) of the same spec says:
 155     *
 156     *     "The commands....are equivalent to the commands with the same base
 157     *     name (without the BaseVertex suffix), except that the ith element
 158     *     transferred by the corresponding draw call will be taken from
 159     *     element indices[i] + basevertex of each enabled array."
 160     *
 161     * Additionally, the overview in the GL_ARB_shader_draw_parameters spec
 162     * says:
 163     *
 164     *     "In unextended GL, vertex shaders have inputs named gl_VertexID and
 165     *     gl_InstanceID, which contain, respectively the index of the vertex
 166     *     and instance. The value of gl_VertexID is the implicitly passed
 167     *     index of the vertex being processed, which includes the value of
 168     *     baseVertex, for those commands that accept it."
 169     *
 170     * gl_VertexID gets basevertex added in.  This differs from DirectX where
 171     * SV_VertexID does \b not get basevertex added in.
 172     *
 173     * \note
 174     * If all system values are available, \c SYSTEM_VALUE_VERTEX_ID will be
 175     * equal to \c SYSTEM_VALUE_VERTEX_ID_ZERO_BASE plus
 176     * \c SYSTEM_VALUE_BASE_VERTEX.
 177     *
 178     * \sa SYSTEM_VALUE_VERTEX_ID_ZERO_BASE, SYSTEM_VALUE_BASE_VERTEX
 179     */
 180    SYSTEM_VALUE_VERTEX_ID,
 181
 182    /**
 183     * Instanced ID as supplied to gl_InstanceID
 184     *
 185     * Values assigned to gl_InstanceID always begin with zero, regardless of
 186     * the value of baseinstance.
 187     *
 188     * Section 11.1.3.9 (Shader Inputs) of the OpenGL 4.4 core profile spec
 189     * says:
 190     *
 191     *     "gl_InstanceID holds the integer instance number of the current
 192     *     primitive in an instanced draw call (see section 10.5)."
 193     *
 194     * Through a big chain of pseudocode, section 10.5 describes that
 195     * baseinstance is not counted by gl_InstanceID.  In that section, notice
 196     *
 197     *     "If an enabled vertex attribute array is instanced (it has a
 198     *     non-zero divisor as specified by VertexAttribDivisor), the element
 199     *     index that is transferred to the GL, for all vertices, is given by
 200     *
 201     *         floor(instance/divisor) + baseinstance
 202     *
 203     *     If an array corresponding to an attribute required by a vertex
 204     *     shader is not enabled, then the corresponding element is taken from
 205     *     the current attribute state (see section 10.2)."
 206     *
 207     * Note that baseinstance is \b not included in the value of instance.
 208     */
 209    SYSTEM_VALUE_INSTANCE_ID,
 210
 211    /**
 212     * DirectX-style vertex ID.
 213     *
 214     * Unlike \c SYSTEM_VALUE_VERTEX_ID, this system value does \b not include
 215     * the value of basevertex.
 216     *
 217     * \sa SYSTEM_VALUE_VERTEX_ID, SYSTEM_VALUE_BASE_VERTEX
 218     */
 219    SYSTEM_VALUE_VERTEX_ID_ZERO_BASE,
 220
 221    /**
 222     * Value of \c basevertex passed to \c glDrawElementsBaseVertex and similar
 223     * functions.
 224     *
 225     * \sa SYSTEM_VALUE_VERTEX_ID, SYSTEM_VALUE_VERTEX_ID_ZERO_BASE
 226     */
 227    SYSTEM_VALUE_BASE_VERTEX,
 228    /*@}*/
 229
 230    /**
 231     * \name Geometry shader system values
 232     */
 233    /*@{*/
 234    SYSTEM_VALUE_INVOCATION_ID,  /**< (Also in Tessellation Control shader) */
 235    /*@}*/
 236
 237    /**
 238     * \name Fragment shader system values
 239     */
 240    /*@{*/
 241    SYSTEM_VALUE_FRONT_FACE,     /**< (not done yet) */
 242    SYSTEM_VALUE_SAMPLE_ID,
 243    SYSTEM_VALUE_SAMPLE_POS,
 244    SYSTEM_VALUE_SAMPLE_MASK_IN,
 245    /*@}*/
 246
 247    /**
 248     * \name Tessellation Evaluation shader system values
 249     */
 250    /*@{*/
 251    SYSTEM_VALUE_TESS_COORD,
 252    SYSTEM_VALUE_VERTICES_IN,    /**< Tessellation vertices in input patch */
 253    SYSTEM_VALUE_PRIMITIVE_ID,   /**< (currently not used by GS) */
 254    SYSTEM_VALUE_TESS_LEVEL_OUTER, /**< TES input */
 255    SYSTEM_VALUE_TESS_LEVEL_INNER, /**< TES input */
 256    /*@}*/
 257
 258    SYSTEM_VALUE_MAX             /**< Number of values */
 259 } gl_system_value;
 260
 261
 262 /**
 263  * The possible interpolation qualifiers that can be applied to a fragment
 264  * shader input in GLSL.
 265  *
 266  * Note: INTERP_QUALIFIER_NONE must be 0 so that memsetting the
 267  * gl_fragment_program data structure to 0 causes the default behavior.
 268  */
 269 enum glsl_interp_qualifier
 270 {
 271    INTERP_QUALIFIER_NONE = 0,
 272    INTERP_QUALIFIER_SMOOTH,
 273    INTERP_QUALIFIER_FLAT,
 274    INTERP_QUALIFIER_NOPERSPECTIVE,
 275    INTERP_QUALIFIER_COUNT /**< Number of interpolation qualifiers */
 276 };
 277
 278 /**
 279  * Fragment program results
 280  */
 281 typedef enum
 282 {
 283    FRAG_RESULT_DEPTH = 0,
 284    FRAG_RESULT_STENCIL = 1,
 285    /* If a single color should be written to all render targets, this
 286     * register is written.  No FRAG_RESULT_DATAn will be written.
 287     */
 288    FRAG_RESULT_COLOR = 2,
 289    FRAG_RESULT_SAMPLE_MASK = 3,
 290
 291    /* FRAG_RESULT_DATAn are the per-render-target (GLSL gl_FragData[n]
 292     * or ARB_fragment_program fragment.color[n]) color results.  If
 293     * any are written, FRAG_RESULT_COLOR will not be written.
 294     */
 295    FRAG_RESULT_DATA0 = 4,
 296 } gl_frag_result;
 297
 298 #endif /* SHADER_ENUMS_H */