skia / external / github.com / KhronosGroup / OpenGL-Registry / refs/heads/310-issue / . / extensions / ARB / ARB_gpu_shader_int64.txt

Name | |

ARB_gpu_shader_int64 | |

Name Strings | |

GL_ARB_gpu_shader_int64 | |

Contact | |

Daniel Rakos, AMD (daniel.rakos 'at' amd.com) | |

Contributors | |

Daniel Rakos, AMD | |

Graham Sellers, AMD | |

Notice | |

Copyright (c) 2015 The Khronos Group Inc. Copyright terms at | |

http://www.khronos.org/registry/speccopyright.html | |

Specification Update Policy | |

Khronos-approved extension specifications are updated in response to | |

issues and bugs prioritized by the Khronos OpenGL Working Group. For | |

extensions which have been promoted to a core Specification, fixes will | |

first appear in the latest version of that core Specification, and will | |

eventually be backported to the extension document. This policy is | |

described in more detail at | |

https://www.khronos.org/registry/OpenGL/docs/update_policy.php | |

Status | |

Complete. Approved by the ARB on June 26, 2015. | |

Ratified by the Khronos Board of Promoters on August 7, 2015. | |

Version | |

Last Modified Date: 02/03/2015 | |

Author Revision: 1 | |

Number | |

ARB Extension #178 | |

Dependencies | |

This extension is written against the OpenGL 4.5 (Core Profile) | |

Specification. | |

This extension is written against version 4.50 of the OpenGL Shading | |

Language Specification. | |

OpenGL 4.0 and GLSL 4.00 are required. | |

This extension interacts with AMD_gpu_shader_int64. | |

This extension interacts with NV_gpu_shader5. | |

This extension interacts with NV_shader_buffer_load. | |

This extension interacts with NV_vertex_attrib_integer_64bit. | |

Overview | |

The extension introduces the following features for all shader types: | |

* support for 64-bit scalar and vector integer data types, including | |

uniform API, uniform buffer object, transform feedback, and shader | |

input and output support; | |

* new built-in functions to pack and unpack 64-bit integer types into a | |

two-component 32-bit integer vector; | |

* new built-in functions to convert double-precision floating-point | |

values to or from their 64-bit integer bit encodings; | |

* vector relational functions supporting comparisons of vectors of | |

64-bit integer types; and | |

* common functions abs, sign, min, max, clamp, and mix supporting | |

arguments of 64-bit integer types. | |

New Procedures and Functions | |

void Uniform1i64ARB(int location, int64 x); | |

void Uniform2i64ARB(int location, int64 x, int64 y); | |

void Uniform3i64ARB(int location, int64 x, int64 y, int64 z); | |

void Uniform4i64ARB(int location, int64 x, int64 y, int64 z, int64 w); | |

void Uniform1i64vARB(int location, sizei count, const int64 *value); | |

void Uniform2i64vARB(int location, sizei count, const int64 *value); | |

void Uniform3i64vARB(int location, sizei count, const int64 *value); | |

void Uniform4i64vARB(int location, sizei count, const int64 *value); | |

void Uniform1ui64ARB(int location, uint64 x); | |

void Uniform2ui64ARB(int location, uint64 x, uint64 y); | |

void Uniform3ui64ARB(int location, uint64 x, uint64 y, uint64 z); | |

void Uniform4ui64ARB(int location, uint64 x, uint64 y, uint64 z, uint64 w); | |

void Uniform1ui64vARB(int location, sizei count, const uint64 *value); | |

void Uniform2ui64vARB(int location, sizei count, const uint64 *value); | |

void Uniform3ui64vARB(int location, sizei count, const uint64 *value); | |

void Uniform4ui64vARB(int location, sizei count, const uint64 *value); | |

void GetUniformi64vARB(uint program, int location, int64 *params); | |

void GetUniformui64vARB(uint program, int location, uint64 *params); | |

void GetnUniformi64vARB(uint program, int location, sizei bufSize, | |

int64 *params); | |

void GetnUniformui64vARB(uint program, int location, sizei bufSize, | |

uint64 *params); | |

void ProgramUniform1i64ARB(uint program, int location, int64 x); | |

void ProgramUniform2i64ARB(uint program, int location, int64 x, int64 y); | |

void ProgramUniform3i64ARB(uint program, int location, int64 x, int64 y, | |

int64 z); | |

void ProgramUniform4i64ARB(uint program, int location, int64 x, int64 y, | |

int64 z, int64 w); | |

void ProgramUniform1i64vARB(uint program, int location, sizei count, | |

const int64 *value); | |

void ProgramUniform2i64vARB(uint program, int location, sizei count, | |

const int64 *value); | |

void ProgramUniform3i64vARB(uint program, int location, sizei count, | |

const int64 *value); | |

void ProgramUniform4i64vARB(uint program, int location, sizei count, | |

const int64 *value); | |

void ProgramUniform1ui64ARB(uint program, int location, uint64 x); | |

void ProgramUniform2ui64ARB(uint program, int location, uint64 x, uint64 y); | |

void ProgramUniform3ui64ARB(uint program, int location, uint64 x, uint64 y, | |

uint64 z); | |

void ProgramUniform4ui64ARB(uint program, int location, uint64 x, uint64 y, | |

uint64 z, uint64 w); | |

void ProgramUniform1ui64vARB(uint program, int location, sizei count, | |

const uint64 *value); | |

void ProgramUniform2ui64vARB(uint program, int location, sizei count, | |

const uint64 *value); | |

void ProgramUniform3ui64vARB(uint program, int location, sizei count, | |

const uint64 *value); | |

void ProgramUniform4ui64vARB(uint program, int location, sizei count, | |

const uint64 *value); | |

New Tokens | |

Returned by the <type> parameter of GetActiveAttrib, GetActiveUniform, and | |

GetTransformFeedbackVarying: | |

INT64_ARB 0x140E | |

UNSIGNED_INT64_ARB 0x140F | |

INT64_VEC2_ARB 0x8FE9 | |

INT64_VEC3_ARB 0x8FEA | |

INT64_VEC4_ARB 0x8FEB | |

UNSIGNED_INT64_VEC2_ARB 0x8FF5 | |

UNSIGNED_INT64_VEC3_ARB 0x8FF6 | |

UNSIGNED_INT64_VEC4_ARB 0x8FF7 | |

Additions to Chapter 7 of the OpenGL 4.5 (Core Profile) Specification | |

(Program Objects) | |

Modify Section 7.3.1, Program Interfaces | |

(add to Table 7.3, OpenGL Shading Language type tokens, p. 112) | |

+----------------------------+--------------+--------+--------+--------+ | |

| Type Name Token | Keyword | Attrib | Xfb | Buffer | | |

+----------------------------+--------------+--------+--------+--------+ | |

| INT64_ARB | int64_t | * | * | * | | |

| INT64_VEC2_ARB | i64vec2 | * | * | * | | |

| INT64_VEC3_ARB | i64vec3 | * | * | * | | |

| INT64_VEC4_ARB | i64vec4 | * | * | * | | |

| UNSIGNED_INT64_ARB | uint64_t | * | * | * | | |

| UNSIGNED_INT64_VEC2_ARB | u64vec2 | * | * | * | | |

| UNSIGNED_INT64_VEC3_ARB | u64vec3 | * | * | * | | |

| UNSIGNED_INT64_VEC4_ARB | u64vec4 | * | * | * | | |

+----------------------------+--------------+--------+--------+--------+ | |

Modify Section 7.6, Uniform Variables | |

(modify second paragraph on p. 125) | |

Scalar, vector, and matrix uniforms with double-precision components, | |

and scalar and vector uniforms with 64-bit integer components will consume | |

no more than twice the number of components of equivalent uniforms with | |

single-precision components. | |

Modify Section 7.6.1, Loading Uniform Variables | |

(add to the list of commands in first paragraph on p. 132) | |

void Uniform{1,2,3,4}{i64,ui64}ARB(int location, T value); | |

void Uniform{1,2,3,4}{i64,ui64}vARB(int location, const T *value); | |

(insert after sixth paragraph on p. 132) | |

The Uniform*i64{v}ARB and Uniform*ui{v}ARB commands will load count sets | |

of one to four 64-bit signed or unsigned integer values into a uniform | |

location defined as a 64-bit signed or unsigned integer scalar or vector | |

types. | |

(add to the list of commands in first paragraph on p. 134) | |

void ProgramUniform{1,2,3,4}{i64,ui64}ARB(uint program, int location, | |

T value); | |

void ProgramUniform{1,2,3,4}{i64,ui64}vARB(uint program, int location, | |

const T *value); | |

Modify Section 7.6.2.1, Uniform Buffer Object Storage | |

(modify the first two bullets of the first paragraph on p. 136) | |

* Members of type bool int, uint, float, double, int64_t, and uint64_t | |

are respectively extracted from a buffer object by reading a single | |

uint, int, uint, float, double, int64_t, or uint64_t value at the | |

specified offset. | |

* Vectors with N elements with basic data types of bool, int, uint, | |

float, double, int64_t, or uint64_t are extracted as N values in | |

consecutive memory locations beginning at the specified offset, with | |

components stored in order with the first (X) component at the | |

lowest offset. The GL data type used for component extraction is | |

derived according to the rules for scalar members above. | |

Modify Section 7.13, Shader, Program, and Program Pipeline Queries | |

(add to the list of commands in last paragraph on p. 162) | |

void GetUniformi64vARB(uint program, int location, int64 *params); | |

void GetUniformui64vARB(uint program, int location, uint64 *params); | |

void GetnUniformi64vARB(uint program, int location, sizei bufSize, | |

int64 *params); | |

void GetnUniformui64vARB(uint program, int location, sizei bufSize, | |

uint64 *params); | |

Additions to Chapter 11 of the OpenGL 4.5 (Core Profile) Specification | |

(Programmable Vertex Processing) | |

Modify Section 11.1.1, Vertex Attributes | |

(modify third sentence of second paragraph on p. 368) | |

... hardware resources. For the purposes of this test, attribute variables | |

of the type dvec3, dvec4, dmat2x3, dmat2x3, dmat3, dmat3x4, dmat4x3, | |

dmat4, i64vec3, i64vec4, u64vec3, and u64vec4 may count as consuming twice | |

as many attributes as equivalent single-precision types. While these types | |

use the same number of generic attributes as their single-precision | |

vectors of internal storage for each three- or four-component | |

double-precision or 64-bit integer vector. | |

Modify Section 11.1.2.1, Output Variables | |

(modify last sentence of fourth paragraph on p. 369) | |

... multiple components. Each component of variables declared as double- | |

precision floating point scalars, vectors, or matrices, or declared as | |

64-bit integer scalars or vectors may be counted as consuming two | |

components. | |

(modify third bullet of the first paragraph on p. 373) | |

* any variable containing double-precision floating-point or 64-bit | |

integer components | |

- has an xfb_offset layout qualifier that is not a multiple of eight; | |

or | |

- is associated with a binding point with an xfb_stride layout | |

qualifier that is not a multiple of eight; | |

(modify second paragraph on p. 373) | |

For transform feedback purposes, each component of outputs declared as | |

double-precision floating-point scalars, vectors, or matrices, or 64-bit | |

integer scalars or vectors are considered to consume eight basic machine | |

units, and each component of any other type is considered to consume four | |

basic machine units. | |

Modifications to the OpenGL Shading Language Specification, Version 4.50 | |

Including the following line in a shader can be used to control the | |

language features described in this extension: | |

#extension GL_ARB_gpu_shader_int64 : <behavior> | |

where <behavior> is as specified in section 3.3. | |

New preprocessor #defines are added to the OpenGL Shading Language: | |

#define GL_ARB_gpu_shader_int64 1 | |

Additions to Chapter 3 of the OpenGL Shading Language Specification (Basics) | |

Modify Section 3.6, Keywords | |

(add the following to the list of reserved keywords at p. 17) | |

int64_t i64vec2 i64vec3 i64vec4 uint64_t u64vec2 u64vec3 u64vec4 | |

Additions to Chapter 4 of the OpenGL Shading Language Specification | |

(Variables and Types) | |

Modify Section 4.1, Basic Types | |

(add to the basic "Transparent Types" table, p. 21) | |

+-----------+------------------------------------------------------------+ | |

| Type | Meaning | | |

+-----------+------------------------------------------------------------+ | |

| int64_t | a 64-bit signed integer | | |

| uint64_t | a 64-bit unsigned integer | | |

| i64vec2 | a two-component 64-bit signed integer vector | | |

| i64vec3 | a three-component 64-bit signed integer vector | | |

| i64vec4 | a four-component 64-bit signed integer vector | | |

| u64vec2 | a two-component 64-bit unsigned integer vector | | |

| u64vec3 | a three-component 64-bit unsigned integer vector | | |

| u64vec4 | a four-component 64-bit unsigned integer vector | | |

+-----------+------------------------------------------------------------+ | |

Modify Section 4.1.3, Integers | |

(replace first paragraph of the section, p. 25) | |

Signed and unsigned integer variables are fully supported. In this | |

document, the term integer is meant to generally include both signed and | |

unsigned integers, including both 32-bit and 64-bit integers. Unsigned | |

integers of type uint, uvec2, uvec3, and uvec4 have exactly 32 bits of | |

precision, while unsigned integers of type uint64_t, u64vec2, u64vec3, and | |

u64vec4 have exactly 64 bits of precision. Signed integers of type int, | |

ivec2, ivec3, and ivec4 have exactly 32 bits of precision, while signed | |

integers of type int64_t, i64vec2, i64vec3, and i64vec4 have exactly | |

64 bits of precision. Addition, subtraction, and shift operations | |

resulting in overflow or underflow will not cause any exceptions, nor | |

will they saturate, rather they will "wrap" to yield the low-order bits | |

of the result. Divison and multiplication operations resulting in overflow | |

or underflow will not cause any exception but will result in an undefined | |

value. | |

(add after the first paragraph of the section, p. 25) | |

Variables with the types "int64_t" and "uint64_t" represent signed and | |

unsigned integer values, respectively, with exactly 64 bits of precision. | |

(modify grammar rule for "integer-suffix", p. 26) | |

integer-suffix: one of | |

u U l L ul UL | |

(modify first sentence of second paragraph on p. 26) | |

No white space is allowed between the digits of an integer constant, | |

including after the leading 0 or after the leading 0x or 0X of a constant, | |

or before the suffix u, U, l, L, ul, or UL. | |

(modify third sentence of second paragraph on p. 26) | |

When the suffix u or U is present, the literal has type uint. When the | |

suffix l or L is present, the literal has type int64_t. When the suffix | |

ul or UL is present, the literal has type uint64_t. Otherwise, the type is | |

int. | |

Modify Section 4.1.10, Implicit Conversions | |

(modify table of implicit conversions on p. 35) | |

+----------------------+-------------------------------------------------+ | |

| Type of expression | Can be implicitly converted to | | |

+----------------------+-------------------------------------------------+ | |

| int | uint, int64_t, uint64_t, float, double | | |

| uint | uint64_t, float, double | | |

| int64_t | uint64_t, double | | |

| uint64_t | double | | |

| ivec2 | uvec2, i64vec2, u64vec2, vec2, dvec2 | | |

| ivec3 | uvec3, i64vec3, u64vec3, vec3, dvec3 | | |

| ivec4 | uvec4, i64vec4, u64vec4, vec4, dvec4 | | |

| uvec2 | u64vec2, vec2, dvec2 | | |

| uvec3 | u64vec3, vec3, dvec3 | | |

| uvec4 | u64vec4, vec4, dvec4 | | |

| i64vec2 | u64vec2, dvec2 | | |

| i64vec3 | u64vec3, dvec3 | | |

| i64vec4 | u64vec4, dvec4 | | |

| u64vec2 | dvec2 | | |

| u64vec3 | dvec3 | | |

| u64vec4 | dvec4 | | |

+----------------------+-------------------------------------------------+ | |

Modify Section 4.3.6, Output Variables | |

(add new bullet to the list in the second paragraph on p. 49) | |

* A 64-bit integer scalar or vector (int64_t, uint64_t, i64vec2, i64vec3, | |

i64vec4, u64vec2, u64vec3, u64vec4) | |

Additions to Chapter 5 of the OpenGL Shading Language Specification | |

(Operators and Expressions) | |

Modify Section 5.4.1, Conversion and Scalar Constructors | |

(add to the constructor propotype list on p. 95) | |

int(int64_t) // converts a 64-bit signed integer to a 32-bit signed integer | |

int(uint64_t) // converts a 64-bit unsigned integer to a 32-bit signed integer | |

uint(int64_t) // converts a 64-bit signed integer to a 32-bit unsigned integer | |

uint(uint64_t) // converts a 64-bit unsigned integer to a 32-bit unsigned integer | |

bool(int64_t) // converts a 64-bit signed integer to a Boolean | |

bool(uint64_t) // converts a 64-bit unsigned integer to a Boolean | |

float(int64_t) // converts a 64-bit signed integer to a float | |

float(uint64_t) // converts a 64-bit unsigned integer to a float | |

double(int64_t) // converts a 64-bit signed integer to a double | |

double(uint64_t) // converts a 64-bit unsigned integer to a double | |

int64_t(int) // converts a 32-bit signed integer to a 64-bit signed integer | |

int64_t(uint) // converts a 32-bit unsigned integer to a 64-bit signed integer | |

int64_t(bool) // converts a Boolean to a 64-bit signed integer | |

int64_t(float) // converts a float to a 64-bit signed integer | |

int64_t(double) // converts a double to a 64-bit signed integer | |

uint64_t(int) // converts a 32-bit signed integer to a 64-bit unsigned integer | |

uint64_t(uint) // converts a 32-bit unsigned integer to a 64-bit unsigned integer | |

uint64_t(bool) // converts a Boolean to a 64-bit unsigned integer | |

uint64_t(float) // converts a float to a 64-bit unsigned integer | |

uint64_t(double) // converts a double to a 64-bit unsigned integer | |

(modify second sentence of first paragraph on p. 96) | |

... is dropped. It is undefined to convert a negative floating-point value | |

to an uint or uint64_t. | |

(replace third paragraph on p. 96) | |

The constructors int(uint) and int64_t(uint64_t) preserve the bit pattern | |

in the argument, which will change the argument's value if its sign bit is | |

set. The constructor uint(int) and uint64_t(int64_t) preserve the bit | |

pattern in the argument, which will change its value if it is negative. | |

Additions to Chapter 6 of the OpenGL Shading Language Specification | |

(Statements and Structure) | |

Modify Section 6.1, Function Defintions | |

(replace second rule in third paragraph on p. 111) | |

2. A match involving a conversion from a signed integer, unsigned | |

integer, or floating-point type to a similar type having a larger | |

number of bits is better than a match involving any other implicit | |

conversion. | |

Additions to Chapter 8 of the OpenGL Shading Language Specification | |

(Built-in Functions) | |

(insert after third sentence of last paragraph on p. 138) | |

... genUType is used as the argument. Where the input arguments (and | |

corresponding output) can be int64_t, i64vec2, i64vec3, i64vec4, | |

genI64Type is used as the argument. Where the input arguments (and | |

corresponding output) can be uint64_t, u64vec2, u64vec3, u64vec4, | |

genU64Type is used as the argument. | |

Modify Section 8.3, Common Functions | |

(add to the table of common functions on p. 142) | |

+------------------------------------------------+----------------------------------------------------+ | |

| Syntax | Desciption | | |

+------------------------------------------------+----------------------------------------------------+ | |

| genI64Type abs(genI64Type x) | Returns x if x >= 0; otherwise it returns -x. | | |

+------------------------------------------------+----------------------------------------------------+ | |

| genI64Type sign(genI64Type x) | Returns 1 if x > 0, 0 if x = 0, or -1 if x < 0. | | |

| genI64Type min(genI64Type x, | Returns y if y < x; otherwise it returns x. | | |

| genI64Type y) | | | |

| genI64Type min(genI64Type x, | | | |

| int64_t y) | | | |

| genU64Type min(genU64Type x, | | | |

| genU64Type y) | | | |

| genU64Type min(genU64Type x, | | | |

| uint64_t y) | | | |

| genI64Type max(genI64Type x, | Returns y if x < y; otherwise it returns x. | | |

| genI64Type y) | | | |

| genI64Type max(genI64Type x, | | | |

| int64_t y) | | | |

| genU64Type max(genU64Type x, | | | |

| genU64Type y) | | | |

| genU64Type max(genU64Type x, | | | |

| uint64_t y) | | | |

| genI64Type clamp(genI64Type x, | Returns min(max(x, minVal), maxVal). | | |

| genI64Type minVal, | | | |

| genI64Type maxVal) | Results are undefined if minVal > maxVal. | | |

| genI64Type clamp(genI64Type x, | | | |

| int64_t minVal, | | | |

| int64_t maxVal) | | | |

| genU64Type clamp(genU64Type x, | | | |

| genU64Type minVal, | | | |

| genU64Type maxVal) | | | |

| genU64Type clamp(genU64Type x, | | | |

| uint64_t minVal, | | | |

| uint64_t maxVal) | | | |

| genI64Type mix(genI64Type x, | Selects which vector each returned component comes | | |

| genI64Type y, | from. For a component of a that is false, the | | |

| genBType a) | corresponding component of x is returned. For a | | |

| genU64Type mix(genU64Type x, | component of a that is true, the corresponding | | |

| genU64Type y, | component of y is returned. | | |

| genBType a) | | | |

| genI64Type doubleBitsToInt64(genDType value) | Returns a signed or unsigned 64-bit integer value | | |

| genU64Type doubleBitsToUint64(genDType value) | representing the encoding of a double. The double | | |

| | value's bit-level representation is preserved | | |

| genDType int64BitsToDouble(genI64Type value) | Returns a double value corresponding to a signed | | |

| genDType uint64BitsToDouble(genU64Type value) | or unsigned integer encoding of a double. If a NaN | | |

| | is passed in, it will not signal, and the | | |

| | resulting value is unspecified. If an Inf is | | |

| | passed in, the resulting value is the | | |

| | corresponding Inf. | | |

Rename Section 8.4, Floating-Point Pack and Unpack Functions to | |

8.4, Floating-Point and Integer Pack and Unpack Functions | |

Modify Section 8.4, Floating-Point and Integer Pack and Unpack Functions | |

(add to the table of pack and unpack functions on p. 147) | |

+-----------------------------------+------------------------------------------------------+ | |

| Syntax | Desciption | | |

+-----------------------------------+------------------------------------------------------+ | |

| int64_t packInt2x32(ivec2 v) | Returns a signed or unsigned 64-bit integer obtained | | |

| uint64_t packUint2x32(uvec2 v) | by packing the components of a two-component signed | | |

| | or unsigned integer vector, respectively. The first | | |

| | vector component specifies the 32 least significant | | |

| | bits; the second component specifies the 32 most | | |

| | significant bits. | | |

+-----------------------------------+------------------------------------------------------+ | |

| ivec2 unpackInt2x32(int64_t v) | Returns a signed or unsigned integer vector built | | |

| uvec2 unpackUint2x32(uint64_t v) | from a 64-bit signed or unsigned integer scalar, | | |

| | respectively. The first component of the vector | | |

| | contains the 32 least significant bits of the input; | | |

| | the second component contains the 32 most | | |

| | significant bits. | | |

+-----------------------------------+------------------------------------------------------+ | |

Modify Section, 8.7, Vector Relational Functions | |

(add to the table of placeholders at the top of p. 154) | |

+-------------+-----------------------------+ | |

| Placeholder | Specific Types Allowed | | |

+-------------+-----------------------------+ | |

| i64vec | i64vec2, i64vec3, i64vec4 | | |

| u64vec | u64vec2, u64vec3, u64vec4 | | |

+-------------+-----------------------------+ | |

(add to the table of vector relational functions at the bottom of p. 154) | |

+-------------------------------------------+-----------------------------------------------+ | |

| Syntax | Desciption | | |

+-------------------------------------------+-----------------------------------------------+ | |

| bvec lessThan(i64vec x, i64vec y) | Returns the component-wise compare of x < y. | | |

| bvec lessThan(u64vec x, u64vec y) | | | |

+-------------------------------------------+-----------------------------------------------+ | |

| bvec lessThanEqual(i64vec x, i64vec y) | Returns the component-wise compare of x <= y. | | |

| bvec lessThanEqual(u64vec x, u64vec y) | | | |

+-------------------------------------------+-----------------------------------------------+ | |

| bvec greaterThan(i64vec x, i64vec y) | Returns the component-wise compare of x > y. | | |

| bvec greaterThan(u64vec x, u64vec y) | | | |

+-------------------------------------------+-----------------------------------------------+ | |

| bvec greaterThanEqual(i64vec x, i64vec y) | Returns the component-wise compare of x >= y. | | |

| bvec greaterThanEqual(u64vec x, u64vec y) | | | |

+-------------------------------------------+-----------------------------------------------+ | |

| bvec equal(i64vec x, i64vec y) | Returns the component-wise compare of x == y. | | |

| bvec equal(u64vec x, u64vec y) | | | |

+-------------------------------------------+-----------------------------------------------+ | |

| bvec notEqual(i64vec x, i64vec y) | Returns the component-wise compare of x != y. | | |

| bvec notEqual(u64vec x, u64vec y) | | | |

+-------------------------------------------+-----------------------------------------------+ | |

Modify Section 9, Shading Language Grammar for Core Profile | |

(add to the list of tokens on p. 187) | |

... | |

INT64 UINT64 I64VEC2 I64VEC3 I64VEC4 U64VEC2 U64VEC3 U64VEC4 | |

... | |

INT64CONSTANT UINT64CONSTANT | |

(add to the rule of "primary_expression" on p. 188) | |

primary_expression: | |

... | |

INT64CONSTANT | |

UINT64CONSTANT | |

... | |

(add to the rule of "type_specifier_nonarray" on p. 195) | |

type_specifier_nonarray: | |

... | |

INT64 | |

UINT64 | |

... | |

I64VEC2 | |

I64VEC3 | |

I64VEC4 | |

U64VEC2 | |

U64VEC3 | |

U64VEC4 | |

... | |

Dependencies on NV_gpu_shader5 | |

If the shader enables only NV_gpu_shader5, but not ARB_gpu_shader_int64 | |

then the overloaded built-in functions abs, sign, min, max, clamp, and mix | |

are not available. | |

Dependencies on NV_shader_buffer_load | |

If NV_shader_buffer_load is supported, that specification should be edited | |

as follows, to allow pointers to dereference the new data types added by | |

this extension. | |

Modify "Section 2.20.X, Shader Memory Access" from NV_shader_buffer_load. | |

(add rules for loads of variables having the new data types from this | |

extension to the list of bullets following "When a shader dereferences a | |

pointer variable") | |

- Data of type int64_t and uint64_t are read from or written to memory as | |

a signel 64-bit signed and unsigned integer value, respectively, at the | |

specified GPU address. | |

Dependencies on NV_vertex_attrib_integer_64bit | |

This extension only provides the ability to specify 64-bit integer input | |

variables in a GLSL vertex shader, but does not provide a way to specify | |

the values of the corresponding vertex attributes via the OpenGL API. | |

The NV_vertex_attrib_integer_64bit extension exactly provides that | |

functionality. | |

Errors | |

None. | |

New State | |

None. | |

New Implementation Dependent State | |

None. | |

Issues | |

(1) How the functionality in this extension is different than the 64-bit | |

integer support introduced by NV_gpu_shader5 and AMD_gpu_shader_int64? | |

RESOLVED: This extension is a functional superset of the 64-bit integer | |

support in NV_gpu_shader5 with the following additions: | |

* support for overloaded versions of the functions abs, sign, min, | |

max, clamp, and mix that accept 64-bit integers as parameters. | |

Also, this extension is equivalent with AMD_gpu_shader_int64, except that | |

the entry points now have an ARB suffix. | |

(2) How do the implicit conversions impact binary operators? | |

RESOLVED: For binary operators, we prefer converting to a common type | |

that is as close as possible in size and type to the original | |

expression. | |

(3) How do the implicit conversions impact function overloading rules? | |

RESOLVED: We extend the preference rules in core OpenGL to account | |

for the new data types, adding a rule to favor conversion from 32-bit | |

integers to 64-bit integers over coversions to floating-point values. | |

(4) What should be done to distinguish between 32- and 64-bit integer | |

constants? | |

RESOLVED: We will use "L" and "UL" to identify signed and unsigned | |

64-bit integer constants; the use of "L" matches a similar ("long") | |

suffix in the C programming language. C leaves the size of integer | |

types implementation-dependent, and many implementations require an "LL" | |

suffix to declare 64-bit integer constants. With our size definitions, | |

"L" will be considered sufficient to make an integer constant 64-bit. | |

(5) Should provide support for vertex attributes with 64-bit components, | |

and if so, how should the support be provided in the OpenGL API? | |

RESOLVED: Yes, but in order to specify 64-bit vertex attribute values | |

in the OpenGL API support for NV_vertex_attrib_integer_64bit or a | |

similar extension is also required. | |

(6) Should we support 64-bit integer uniforms in the default uniform | |

block? | |

RESOLVED: Yes, for completeness. | |

(7) Should we support 64-bit integer types as members of uniform blocks, | |

shader storage buffer blocks, or as transform feedback varyings? | |

RESOLVED: Yes, support all of them. 64-bit integers will consume eight | |

basic machine units just like double-precision floating-point variables. | |

(8) How do the uniform loading commands introduced by this extension | |

interact similar commands added by NV_shader_buffer_load? | |

RESOLVED: NV_shader_buffer_load provided the command Uniformui64NV to | |

load pointer uniforms with a single 64-bit unsigned integer. This | |

extension provides vectors of 64-bit unsigned integers, so we needed | |

Uniform{2,3,4}ui64NV commands. We chose to provide a Uniform1ui64NV | |

command, which will be functionally equivalent to Uniformui64NV. | |

(9) Should we provide distinct sized types for 32-bit integers, floats, | |

and doubles? | |

RESOLVED: No. While NV_gpu_shader5 does add such types, it seems there | |

isn't much value in adding those in this extension, especially because | |

this extension strictly focuses on supporting 64-bit integers. | |

(10) Can the 64-bit uniform APIs be used to load values for uniforms of | |

type "bool", "bvec2", "bvec3", or "bvec4"? | |

RESOLVED: No. OpenGL 2.0 and beyond did allow "bool" variable to be | |

set with Uniform*i* and Uniform*f APIs, and OpenGL 3.0 extended that | |

support to Uniform*ui* for orthogonality. But it seems pointless to | |

extended this capability forward to 64-bit Uniform APIs as well. | |

(11) There exists both an UNSIGNED_INT64_AMD and UNSIGNED_INT64_NV token | |

with different values (the former existed earlier) so which token | |

value this extension should reuse? | |

DISCUSSION: No functions in this extension accept these values as | |

inputs, they only should return one of these in various scenarios. | |

RESOLVED: This extension will reuse the value of UNSIGNED_INT64_NV to | |

stay source code compatible with NV_gpu_shader5 and AMD_gpu_shader_int64. | |

Revision History | |

Rev. Date Author Changes | |

---- -------- -------- ------------------------------------------------- | |

1 02/03/15 drakos Draft based on AMD_gpu_shader_int64. | |

Rebased language for GL 4.5 and GLSL 4.50. |