ebiten/internal/shaderir/program.go
2022-12-03 23:09:41 +09:00

494 lines
10 KiB
Go

// Copyright 2020 The Ebiten Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package shaderir offers intermediate representation for shader programs.
package shaderir
import (
"go/constant"
"go/token"
"sort"
"strings"
)
type Program struct {
UniformNames []string
Uniforms []Type
TextureNum int
Attributes []Type
Varyings []Type
Funcs []Func
VertexFunc VertexFunc
FragmentFunc FragmentFunc
reachableUniforms []bool
uniformUint32Counts []int
}
type Func struct {
Index int
InParams []Type
OutParams []Type
Return Type
Block *Block
}
// VertexFunc takes pseudo params, and the number if len(attributes) + len(varyings) + 1.
// If 0 <= index < len(attributes), the params are in-params and represent attribute variables.
// If index == len(attributes), the param is an out-param and repesents the position in vec4 (gl_Position in GLSL)
// If len(attributes) + 1 <= index < len(attributes) + len(varyings) + 1, the params are out-params and represent
// varying variables.
type VertexFunc struct {
Block *Block
}
// FragmentFunc takes pseudo params, and the number is len(varyings) + 2.
// If index == 0, the param represents the coordinate of the fragment (gl_FragCoord in GLSL).
// If 0 < index <= len(varyings), the param represents (index-1)th verying variable.
type FragmentFunc struct {
Block *Block
}
type Block struct {
LocalVars []Type
LocalVarIndexOffset int
Stmts []Stmt
}
type Stmt struct {
Type StmtType
Exprs []Expr
Blocks []*Block
ForVarType Type
ForVarIndex int
ForInit constant.Value
ForEnd constant.Value
ForOp Op
ForDelta constant.Value
InitIndex int
}
type StmtType int
const (
ExprStmt StmtType = iota
BlockStmt
Assign
Init
If
For
Continue
Break
Return
Discard
)
type ConstType int
const (
ConstTypeNone ConstType = iota
ConstTypeBool
ConstTypeInt
ConstTypeFloat
)
type Expr struct {
Type ExprType
Exprs []Expr
Const constant.Value
ConstType ConstType
BuiltinFunc BuiltinFunc
Swizzling string
Index int
Op Op
}
type ExprType int
const (
Blank ExprType = iota
NumberExpr
UniformVariable
TextureVariable
LocalVariable
StructMember
BuiltinFuncExpr
SwizzlingExpr
FunctionExpr
Unary
Binary
Selection
Call
FieldSelector
Index
)
type Op int
const (
Add Op = iota
Sub
NotOp
ComponentWiseMul
MatrixMul
Div
ModOp
LeftShift
RightShift
LessThanOp
LessThanEqualOp
GreaterThanOp
GreaterThanEqualOp
EqualOp
NotEqualOp
VectorEqualOp
VectorNotEqualOp
And
Xor
Or
AndAnd
OrOr
)
func OpFromToken(t token.Token, lhs, rhs Type) (Op, bool) {
switch t {
case token.ADD:
return Add, true
case token.SUB:
return Sub, true
case token.NOT:
return NotOp, true
case token.MUL:
if lhs.IsMatrix() || rhs.IsMatrix() {
return MatrixMul, true
}
return ComponentWiseMul, true
case token.QUO:
return Div, true
case token.REM:
return ModOp, true
case token.SHL:
return LeftShift, true
case token.SHR:
return RightShift, true
case token.LSS:
return LessThanOp, true
case token.LEQ:
return LessThanEqualOp, true
case token.GTR:
return GreaterThanOp, true
case token.GEQ:
return GreaterThanEqualOp, true
case token.EQL:
if lhs.IsVector() || rhs.IsVector() {
return VectorEqualOp, true
}
return EqualOp, true
case token.NEQ:
if lhs.IsVector() || rhs.IsVector() {
return VectorNotEqualOp, true
}
return NotEqualOp, true
case token.AND:
return And, true
case token.XOR:
return Xor, true
case token.OR:
return Or, true
case token.LAND:
return AndAnd, true
case token.LOR:
return OrOr, true
}
return 0, false
}
type BuiltinFunc string
const (
Len BuiltinFunc = "len"
Cap BuiltinFunc = "cap"
BoolF BuiltinFunc = "bool"
IntF BuiltinFunc = "int"
FloatF BuiltinFunc = "float"
Vec2F BuiltinFunc = "vec2"
Vec3F BuiltinFunc = "vec3"
Vec4F BuiltinFunc = "vec4"
IVec2F BuiltinFunc = "ivec2"
IVec3F BuiltinFunc = "ivec3"
IVec4F BuiltinFunc = "ivec4"
Mat2F BuiltinFunc = "mat2"
Mat3F BuiltinFunc = "mat3"
Mat4F BuiltinFunc = "mat4"
Radians BuiltinFunc = "radians" // This function is not used yet (#2253)
Degrees BuiltinFunc = "degrees" // This function is not used yet (#2253)
Sin BuiltinFunc = "sin"
Cos BuiltinFunc = "cos"
Tan BuiltinFunc = "tan"
Asin BuiltinFunc = "asin"
Acos BuiltinFunc = "acos"
Atan BuiltinFunc = "atan"
Atan2 BuiltinFunc = "atan2"
Pow BuiltinFunc = "pow"
Exp BuiltinFunc = "exp"
Log BuiltinFunc = "log"
Exp2 BuiltinFunc = "exp2"
Log2 BuiltinFunc = "log2"
Sqrt BuiltinFunc = "sqrt"
Inversesqrt BuiltinFunc = "inversesqrt"
Abs BuiltinFunc = "abs"
Sign BuiltinFunc = "sign"
Floor BuiltinFunc = "floor"
Ceil BuiltinFunc = "ceil"
Fract BuiltinFunc = "fract"
Mod BuiltinFunc = "mod"
Min BuiltinFunc = "min"
Max BuiltinFunc = "max"
Clamp BuiltinFunc = "clamp"
Mix BuiltinFunc = "mix"
Step BuiltinFunc = "step"
Smoothstep BuiltinFunc = "smoothstep"
Length BuiltinFunc = "length"
Distance BuiltinFunc = "distance"
Dot BuiltinFunc = "dot"
Cross BuiltinFunc = "cross"
Normalize BuiltinFunc = "normalize"
Faceforward BuiltinFunc = "faceforward"
Reflect BuiltinFunc = "reflect"
Refract BuiltinFunc = "refract"
Transpose BuiltinFunc = "transpose"
Texture2DF BuiltinFunc = "texture2D"
Dfdx BuiltinFunc = "dfdx"
Dfdy BuiltinFunc = "dfdy"
Fwidth BuiltinFunc = "fwidth"
DiscardF BuiltinFunc = "discard"
)
func ParseBuiltinFunc(str string) (BuiltinFunc, bool) {
switch BuiltinFunc(str) {
case Len,
Cap,
BoolF,
IntF,
FloatF,
Vec2F,
Vec3F,
Vec4F,
IVec2F,
IVec3F,
IVec4F,
Mat2F,
Mat3F,
Mat4F,
Sin,
Cos,
Tan,
Asin,
Acos,
Atan,
Atan2,
Pow,
Exp,
Log,
Exp2,
Log2,
Sqrt,
Inversesqrt,
Abs,
Sign,
Floor,
Ceil,
Fract,
Mod,
Min,
Max,
Clamp,
Mix,
Step,
Smoothstep,
Length,
Distance,
Dot,
Cross,
Normalize,
Faceforward,
Reflect,
Refract,
Transpose,
Texture2DF,
Dfdx,
Dfdy,
Fwidth,
DiscardF:
return BuiltinFunc(str), true
}
return "", false
}
func IsValidSwizzling(s string) bool {
if len(s) < 1 || 4 < len(s) {
return false
}
const (
xyzw = "xyzw"
rgba = "rgba"
strq = "strq"
)
switch {
case strings.IndexByte(xyzw, s[0]) >= 0:
for _, c := range s {
if strings.IndexRune(xyzw, c) == -1 {
return false
}
}
return true
case strings.IndexByte(rgba, s[0]) >= 0:
for _, c := range s {
if strings.IndexRune(rgba, c) == -1 {
return false
}
}
return true
case strings.IndexByte(strq, s[0]) >= 0:
for _, c := range s {
if strings.IndexRune(strq, c) == -1 {
return false
}
}
return true
}
return false
}
func (p *Program) ReachableFuncsFromBlock(block *Block) []*Func {
indexToFunc := map[int]*Func{}
for _, f := range p.Funcs {
f := f
indexToFunc[f.Index] = &f
}
visited := map[int]struct{}{}
var indices []int
var f func(expr *Expr)
f = func(expr *Expr) {
if expr.Type != FunctionExpr {
return
}
if _, ok := visited[expr.Index]; ok {
return
}
indices = append(indices, expr.Index)
visited[expr.Index] = struct{}{}
walkExprs(f, indexToFunc[expr.Index].Block)
}
walkExprs(f, block)
sort.Ints(indices)
funcs := make([]*Func, 0, len(indices))
for _, i := range indices {
funcs = append(funcs, indexToFunc[i])
}
return funcs
}
func walkExprs(f func(expr *Expr), block *Block) {
if block == nil {
return
}
for _, s := range block.Stmts {
for _, e := range s.Exprs {
walkExprsInExpr(f, &e)
}
for _, b := range s.Blocks {
walkExprs(f, b)
}
}
}
func walkExprsInExpr(f func(expr *Expr), expr *Expr) {
if expr == nil {
return
}
f(expr)
for _, e := range expr.Exprs {
walkExprsInExpr(f, &e)
}
}
func (p *Program) reachableUniformVariablesFromBlock(block *Block) []int {
indexToFunc := map[int]*Func{}
for _, f := range p.Funcs {
f := f
indexToFunc[f.Index] = &f
}
visitedFuncs := map[int]struct{}{}
indices := map[int]struct{}{}
var f func(expr *Expr)
f = func(expr *Expr) {
switch expr.Type {
case UniformVariable:
indices[expr.Index] = struct{}{}
case FunctionExpr:
if _, ok := visitedFuncs[expr.Index]; ok {
return
}
visitedFuncs[expr.Index] = struct{}{}
walkExprs(f, indexToFunc[expr.Index].Block)
}
}
walkExprs(f, block)
is := make([]int, 0, len(indices))
for i := range indices {
is = append(is, i)
}
sort.Ints(is)
return is
}
// FilterUniformVariables replaces uniform variables with nil when they are not used.
// By minimizing uniform variables, more commands can be merged in the graphicscommand package.
func (p *Program) FilterUniformVariables(uniforms []uint32) {
if p.reachableUniforms == nil {
p.reachableUniforms = make([]bool, len(p.Uniforms))
for _, i := range p.reachableUniformVariablesFromBlock(p.VertexFunc.Block) {
p.reachableUniforms[i] = true
}
for _, i := range p.reachableUniformVariablesFromBlock(p.FragmentFunc.Block) {
p.reachableUniforms[i] = true
}
}
if p.uniformUint32Counts == nil {
p.uniformUint32Counts = make([]int, len(p.Uniforms))
for i, typ := range p.Uniforms {
p.uniformUint32Counts[i] = typ.Uint32Count()
}
}
var idx int
for i, n := range p.uniformUint32Counts {
if !p.reachableUniforms[i] {
for j := 0; j < n; j++ {
uniforms[idx+j] = 0
}
}
idx += n
}
}