mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-14 15:07:26 +01:00
640 lines
18 KiB
Go
640 lines
18 KiB
Go
// Copyright 2020 The Ebiten Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package shader
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import (
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"fmt"
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"go/ast"
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gconstant "go/constant"
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"go/token"
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"regexp"
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"strconv"
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"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
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)
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func canTruncateToInteger(v gconstant.Value) bool {
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return gconstant.ToInt(v).Kind() != gconstant.Unknown
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}
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var textureVariableRe = regexp.MustCompile(`\A__t(\d+)\z`)
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func (cs *compileState) parseExpr(block *block, expr ast.Expr, markLocalVariableUsed bool) ([]shaderir.Expr, []shaderir.Type, []shaderir.Stmt, bool) {
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switch e := expr.(type) {
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case *ast.BasicLit:
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switch e.Kind {
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case token.INT:
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return []shaderir.Expr{
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{
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Type: shaderir.NumberExpr,
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Const: gconstant.MakeFromLiteral(e.Value, e.Kind, 0),
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},
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}, []shaderir.Type{{Main: shaderir.Int}}, nil, true
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case token.FLOAT:
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return []shaderir.Expr{
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{
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Type: shaderir.NumberExpr,
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Const: gconstant.MakeFromLiteral(e.Value, e.Kind, 0),
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},
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}, []shaderir.Type{{Main: shaderir.Float}}, nil, true
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default:
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cs.addError(e.Pos(), fmt.Sprintf("literal not implemented: %#v", e))
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}
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case *ast.BinaryExpr:
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var stmts []shaderir.Stmt
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// Prase LHS first for the order of the statements.
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lhs, ts, ss, ok := cs.parseExpr(block, e.X, markLocalVariableUsed)
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if !ok {
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return nil, nil, nil, false
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}
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if len(lhs) != 1 {
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cs.addError(e.Pos(), fmt.Sprintf("multiple-value context is not available at a binary operator: %s", e.X))
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return nil, nil, nil, false
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}
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stmts = append(stmts, ss...)
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lhst := ts[0]
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rhs, ts, ss, ok := cs.parseExpr(block, e.Y, markLocalVariableUsed)
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if !ok {
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return nil, nil, nil, false
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}
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if len(rhs) != 1 {
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cs.addError(e.Pos(), fmt.Sprintf("multiple-value context is not available at a binary operator: %s", e.Y))
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return nil, nil, nil, false
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}
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stmts = append(stmts, ss...)
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rhst := ts[0]
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if lhs[0].Type == shaderir.NumberExpr && rhs[0].Type == shaderir.NumberExpr {
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op := e.Op
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// https://golang.org/pkg/go/constant/#BinaryOp
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// "To force integer division of Int operands, use op == token.QUO_ASSIGN instead of
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// token.QUO; the result is guaranteed to be Int in this case."
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if op == token.QUO && lhs[0].Const.Kind() == gconstant.Int && rhs[0].Const.Kind() == gconstant.Int {
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op = token.QUO_ASSIGN
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}
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var v gconstant.Value
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var t shaderir.Type
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switch op {
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case token.EQL, token.NEQ, token.LSS, token.LEQ, token.GTR, token.GEQ:
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v = gconstant.MakeBool(gconstant.Compare(lhs[0].Const, op, rhs[0].Const))
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t = shaderir.Type{Main: shaderir.Bool}
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default:
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v = gconstant.BinaryOp(lhs[0].Const, op, rhs[0].Const)
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if v.Kind() == gconstant.Float {
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t = shaderir.Type{Main: shaderir.Float}
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} else {
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t = shaderir.Type{Main: shaderir.Int}
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}
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}
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return []shaderir.Expr{
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{
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Type: shaderir.NumberExpr,
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Const: v,
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},
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}, []shaderir.Type{t}, stmts, true
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}
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op, ok := shaderir.OpFromToken(e.Op)
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if !ok {
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cs.addError(e.Pos(), fmt.Sprintf("unexpected operator: %s", e.Op))
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return nil, nil, nil, false
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}
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var t shaderir.Type
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switch {
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case op == shaderir.LessThanOp || op == shaderir.LessThanEqualOp || op == shaderir.GreaterThanOp || op == shaderir.GreaterThanEqualOp || op == shaderir.EqualOp || op == shaderir.NotEqualOp || op == shaderir.AndAnd || op == shaderir.OrOr:
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t = shaderir.Type{Main: shaderir.Bool}
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case lhs[0].Type == shaderir.NumberExpr && rhs[0].Type != shaderir.NumberExpr:
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if rhst.Main == shaderir.Int {
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if !canTruncateToInteger(lhs[0].Const) {
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cs.addError(e.Pos(), fmt.Sprintf("constant %s truncated to integer", lhs[0].Const.String()))
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return nil, nil, nil, false
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}
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lhs[0].ConstType = shaderir.ConstTypeInt
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}
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t = rhst
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case lhs[0].Type != shaderir.NumberExpr && rhs[0].Type == shaderir.NumberExpr:
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if lhst.Main == shaderir.Int {
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if !canTruncateToInteger(rhs[0].Const) {
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cs.addError(e.Pos(), fmt.Sprintf("constant %s truncated to integer", rhs[0].Const.String()))
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return nil, nil, nil, false
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}
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rhs[0].ConstType = shaderir.ConstTypeInt
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}
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t = lhst
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case lhst.Equal(&rhst):
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t = lhst
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case lhst.Main == shaderir.Float || lhst.Main == shaderir.Int:
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switch rhst.Main {
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case shaderir.Int:
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t = lhst
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case shaderir.Float, shaderir.Vec2, shaderir.Vec3, shaderir.Vec4, shaderir.Mat2, shaderir.Mat3, shaderir.Mat4:
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t = rhst
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default:
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cs.addError(e.Pos(), fmt.Sprintf("types don't match: %s %s %s", lhst.String(), e.Op, rhst.String()))
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return nil, nil, nil, false
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}
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case rhst.Main == shaderir.Float || rhst.Main == shaderir.Int:
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switch lhst.Main {
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case shaderir.Int:
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t = rhst
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case shaderir.Float, shaderir.Vec2, shaderir.Vec3, shaderir.Vec4, shaderir.Mat2, shaderir.Mat3, shaderir.Mat4:
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t = lhst
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default:
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cs.addError(e.Pos(), fmt.Sprintf("types don't match: %s %s %s", lhst.String(), e.Op, rhst.String()))
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return nil, nil, nil, false
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}
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case lhst.Main == shaderir.Vec2 && rhst.Main == shaderir.Mat2 ||
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lhst.Main == shaderir.Mat2 && rhst.Main == shaderir.Vec2:
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t = shaderir.Type{Main: shaderir.Vec2}
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case lhst.Main == shaderir.Vec3 && rhst.Main == shaderir.Mat3 ||
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lhst.Main == shaderir.Mat3 && rhst.Main == shaderir.Vec3:
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t = shaderir.Type{Main: shaderir.Vec3}
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case lhst.Main == shaderir.Vec4 && rhst.Main == shaderir.Mat4 ||
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lhst.Main == shaderir.Mat4 && rhst.Main == shaderir.Vec4:
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t = shaderir.Type{Main: shaderir.Vec4}
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default:
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cs.addError(e.Pos(), fmt.Sprintf("invalid expression: %s %s %s", lhst.String(), e.Op, rhst.String()))
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return nil, nil, nil, false
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}
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return []shaderir.Expr{
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{
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Type: shaderir.Binary,
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Op: op,
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Exprs: []shaderir.Expr{lhs[0], rhs[0]},
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},
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}, []shaderir.Type{t}, stmts, true
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case *ast.CallExpr:
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var (
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callee shaderir.Expr
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args []shaderir.Expr
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argts []shaderir.Type
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stmts []shaderir.Stmt
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)
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// Parse the argument first for the order of the statements.
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for _, a := range e.Args {
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es, ts, ss, ok := cs.parseExpr(block, a, markLocalVariableUsed)
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if !ok {
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return nil, nil, nil, false
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}
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if len(es) > 1 && len(e.Args) > 1 {
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cs.addError(e.Pos(), fmt.Sprintf("single-value context and multiple-value context cannot be mixed: %s", e.Fun))
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return nil, nil, nil, false
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}
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args = append(args, es...)
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argts = append(argts, ts...)
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stmts = append(stmts, ss...)
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}
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// TODO: When len(ss) is not 0?
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es, _, ss, ok := cs.parseExpr(block, e.Fun, markLocalVariableUsed)
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if !ok {
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return nil, nil, nil, false
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}
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if len(es) != 1 {
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cs.addError(e.Pos(), fmt.Sprintf("multiple-value context is not available at a callee: %s", e.Fun))
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return nil, nil, nil, false
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}
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callee = es[0]
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stmts = append(stmts, ss...)
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// For built-in functions, we can call this in this position. Return an expression for the function
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// call.
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if callee.Type == shaderir.BuiltinFuncExpr {
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if callee.BuiltinFunc == shaderir.Len || callee.BuiltinFunc == shaderir.Cap {
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if len(args) != 1 {
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cs.addError(e.Pos(), fmt.Sprintf("number of %s's arguments must be 1 but %d", callee.BuiltinFunc, len(args)))
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return nil, nil, nil, false
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}
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if argts[0].Main != shaderir.Array {
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cs.addError(e.Pos(), fmt.Sprintf("%s takes an array but %s", callee.BuiltinFunc, argts[0].String()))
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return nil, nil, nil, false
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}
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return []shaderir.Expr{
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{
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Type: shaderir.NumberExpr,
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Const: gconstant.MakeInt64(int64(argts[0].Length)),
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ConstType: shaderir.ConstTypeInt,
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},
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}, []shaderir.Type{{Main: shaderir.Int}}, stmts, true
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}
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var t shaderir.Type
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switch callee.BuiltinFunc {
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case shaderir.BoolF:
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t = shaderir.Type{Main: shaderir.Bool}
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case shaderir.IntF:
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t = shaderir.Type{Main: shaderir.Int}
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case shaderir.FloatF:
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t = shaderir.Type{Main: shaderir.Float}
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case shaderir.Vec2F:
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t = shaderir.Type{Main: shaderir.Vec2}
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case shaderir.Vec3F:
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t = shaderir.Type{Main: shaderir.Vec3}
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case shaderir.Vec4F:
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t = shaderir.Type{Main: shaderir.Vec4}
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case shaderir.Mat2F:
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t = shaderir.Type{Main: shaderir.Mat2}
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case shaderir.Mat3F:
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t = shaderir.Type{Main: shaderir.Mat3}
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case shaderir.Mat4F:
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t = shaderir.Type{Main: shaderir.Mat4}
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case shaderir.Step:
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t = argts[1]
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case shaderir.Smoothstep:
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t = argts[2]
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case shaderir.Length, shaderir.Distance, shaderir.Dot:
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t = shaderir.Type{Main: shaderir.Float}
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case shaderir.Cross:
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t = shaderir.Type{Main: shaderir.Vec3}
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case shaderir.Texture2DF:
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t = shaderir.Type{Main: shaderir.Vec4}
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default:
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t = argts[0]
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}
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return []shaderir.Expr{
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{
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Type: shaderir.Call,
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Exprs: append([]shaderir.Expr{callee}, args...),
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},
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}, []shaderir.Type{t}, stmts, true
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}
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if callee.Type != shaderir.FunctionExpr {
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cs.addError(e.Pos(), fmt.Sprintf("function callee must be a funciton name but %s", e.Fun))
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return nil, nil, nil, false
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}
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f := cs.funcs[callee.Index]
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for i, p := range f.ir.InParams {
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if args[i].Type == shaderir.NumberExpr && p.Main == shaderir.Int {
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if !cs.forceToInt(e, &args[i]) {
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return nil, nil, nil, false
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}
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}
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}
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var outParams []int
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for _, p := range f.ir.OutParams {
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idx := block.totalLocalVariableNum()
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block.vars = append(block.vars, variable{
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typ: p,
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})
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args = append(args, shaderir.Expr{
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Type: shaderir.LocalVariable,
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Index: idx,
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})
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outParams = append(outParams, idx)
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}
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if t := f.ir.Return; t.Main != shaderir.None {
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if len(outParams) != 0 {
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cs.addError(e.Pos(), fmt.Sprintf("a function returning value cannot have out-params so far: %s", e.Fun))
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return nil, nil, nil, false
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}
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idx := block.totalLocalVariableNum()
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block.vars = append(block.vars, variable{
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typ: t,
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})
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// Calling the function should be done eariler to treat out-params correctly.
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.Assign,
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Exprs: []shaderir.Expr{
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{
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Type: shaderir.LocalVariable,
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Index: idx,
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},
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{
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Type: shaderir.Call,
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Exprs: append([]shaderir.Expr{callee}, args...),
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},
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},
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})
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// The actual expression here is just a local variable that includes the result of the
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// function call.
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return []shaderir.Expr{
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{
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Type: shaderir.LocalVariable,
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Index: idx,
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},
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}, []shaderir.Type{t}, stmts, true
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}
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// Even if the function doesn't return anything, calling the function should be done eariler to keep
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// the evaluation order.
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.ExprStmt,
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Exprs: []shaderir.Expr{
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{
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Type: shaderir.Call,
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Exprs: append([]shaderir.Expr{callee}, args...),
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},
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},
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})
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if len(outParams) == 0 {
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// TODO: Is this an error?
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}
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var exprs []shaderir.Expr
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for _, p := range outParams {
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exprs = append(exprs, shaderir.Expr{
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Type: shaderir.LocalVariable,
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Index: p,
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})
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}
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return exprs, f.ir.OutParams, stmts, true
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case *ast.Ident:
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if e.Name == "_" {
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// In the context where a local variable is marked as used, any expressions must have its
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// meaning. Then, a blank identifier is not available there.
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if markLocalVariableUsed {
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cs.addError(e.Pos(), fmt.Sprintf("cannot use _ as value"))
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return nil, nil, nil, false
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}
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return []shaderir.Expr{
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{
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Type: shaderir.Blank,
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},
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}, []shaderir.Type{{}}, nil, true
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}
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if i, t, ok := block.findLocalVariable(e.Name, markLocalVariableUsed); ok {
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return []shaderir.Expr{
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{
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Type: shaderir.LocalVariable,
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Index: i,
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},
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}, []shaderir.Type{t}, nil, true
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}
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if i, ok := cs.findFunction(e.Name); ok {
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return []shaderir.Expr{
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{
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Type: shaderir.FunctionExpr,
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Index: i,
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},
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}, nil, nil, true
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}
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if i, ok := cs.findUniformVariable(e.Name); ok {
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return []shaderir.Expr{
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{
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Type: shaderir.UniformVariable,
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Index: i,
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},
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}, []shaderir.Type{cs.ir.Uniforms[i]}, nil, true
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}
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if f, ok := shaderir.ParseBuiltinFunc(e.Name); ok {
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return []shaderir.Expr{
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{
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Type: shaderir.BuiltinFuncExpr,
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BuiltinFunc: f,
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},
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}, nil, nil, true
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}
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if m := textureVariableRe.FindStringSubmatch(e.Name); m != nil {
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i, _ := strconv.Atoi(m[1])
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return []shaderir.Expr{
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{
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Type: shaderir.TextureVariable,
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Index: i,
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},
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}, nil, nil, true
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}
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if e.Name == "true" || e.Name == "false" {
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return []shaderir.Expr{
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{
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Type: shaderir.NumberExpr,
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Const: gconstant.MakeBool(e.Name == "true"),
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},
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}, []shaderir.Type{{Main: shaderir.Bool}}, nil, true
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}
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cs.addError(e.Pos(), fmt.Sprintf("unexpected identifier: %s", e.Name))
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case *ast.ParenExpr:
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return cs.parseExpr(block, e.X, markLocalVariableUsed)
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case *ast.SelectorExpr:
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exprs, _, stmts, ok := cs.parseExpr(block, e.X, true)
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if !ok {
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return nil, nil, nil, false
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}
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if len(exprs) != 1 {
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cs.addError(e.Pos(), fmt.Sprintf("multiple-value context is not available at a selector: %s", e.X))
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return nil, nil, nil, false
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}
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var t shaderir.Type
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switch len(e.Sel.Name) {
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case 1:
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t.Main = shaderir.Float
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case 2:
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t.Main = shaderir.Vec2
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case 3:
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t.Main = shaderir.Vec3
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case 4:
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t.Main = shaderir.Vec4
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default:
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cs.addError(e.Pos(), fmt.Sprintf("unexpected swizzling: %s", e.Sel.Name))
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return nil, nil, nil, false
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}
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return []shaderir.Expr{
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{
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Type: shaderir.FieldSelector,
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Exprs: []shaderir.Expr{
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exprs[0],
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{
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Type: shaderir.SwizzlingExpr,
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Swizzling: e.Sel.Name,
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},
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},
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},
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}, []shaderir.Type{t}, stmts, true
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case *ast.UnaryExpr:
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exprs, t, stmts, ok := cs.parseExpr(block, e.X, markLocalVariableUsed)
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if !ok {
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return nil, nil, nil, false
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}
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if len(exprs) != 1 {
|
|
cs.addError(e.Pos(), fmt.Sprintf("multiple-value context is not available at a unary operator: %s", e.X))
|
|
return nil, nil, nil, false
|
|
}
|
|
|
|
if exprs[0].Type == shaderir.NumberExpr {
|
|
v := gconstant.UnaryOp(e.Op, exprs[0].Const, 0)
|
|
t := shaderir.Type{Main: shaderir.Int}
|
|
if v.Kind() == gconstant.Float {
|
|
t = shaderir.Type{Main: shaderir.Float}
|
|
}
|
|
return []shaderir.Expr{
|
|
{
|
|
Type: shaderir.NumberExpr,
|
|
Const: v,
|
|
},
|
|
}, []shaderir.Type{t}, stmts, true
|
|
}
|
|
|
|
var op shaderir.Op
|
|
switch e.Op {
|
|
case token.ADD:
|
|
op = shaderir.Add
|
|
case token.SUB:
|
|
op = shaderir.Sub
|
|
case token.NOT:
|
|
op = shaderir.NotOp
|
|
default:
|
|
cs.addError(e.Pos(), fmt.Sprintf("unexpected operator: %s", e.Op))
|
|
return nil, nil, nil, false
|
|
}
|
|
return []shaderir.Expr{
|
|
{
|
|
Type: shaderir.Unary,
|
|
Op: op,
|
|
Exprs: exprs,
|
|
},
|
|
}, t, stmts, true
|
|
|
|
case *ast.CompositeLit:
|
|
t, ok := cs.parseType(block, e.Type)
|
|
if !ok {
|
|
return nil, nil, nil, false
|
|
}
|
|
if t.Main == shaderir.Array && t.Length == -1 {
|
|
t.Length = len(e.Elts)
|
|
}
|
|
|
|
idx := block.totalLocalVariableNum()
|
|
block.vars = append(block.vars, variable{
|
|
typ: t,
|
|
})
|
|
|
|
var stmts []shaderir.Stmt
|
|
for i, e := range e.Elts {
|
|
exprs, _, ss, ok := cs.parseExpr(block, e, markLocalVariableUsed)
|
|
if !ok {
|
|
return nil, nil, nil, false
|
|
}
|
|
if len(exprs) != 1 {
|
|
cs.addError(e.Pos(), fmt.Sprintf("multiple-value context is not available at a composite literal"))
|
|
return nil, nil, nil, false
|
|
}
|
|
stmts = append(stmts, ss...)
|
|
stmts = append(stmts, shaderir.Stmt{
|
|
Type: shaderir.Assign,
|
|
Exprs: []shaderir.Expr{
|
|
{
|
|
Type: shaderir.Index,
|
|
Exprs: []shaderir.Expr{
|
|
{
|
|
Type: shaderir.LocalVariable,
|
|
Index: idx,
|
|
},
|
|
{
|
|
Type: shaderir.NumberExpr,
|
|
Const: gconstant.MakeInt64(int64(i)),
|
|
ConstType: shaderir.ConstTypeInt,
|
|
},
|
|
},
|
|
},
|
|
exprs[0],
|
|
},
|
|
})
|
|
}
|
|
|
|
return []shaderir.Expr{
|
|
{
|
|
Type: shaderir.LocalVariable,
|
|
Index: idx,
|
|
},
|
|
}, []shaderir.Type{t}, stmts, true
|
|
|
|
case *ast.IndexExpr:
|
|
var stmts []shaderir.Stmt
|
|
|
|
// Parse the index first
|
|
exprs, _, ss, ok := cs.parseExpr(block, e.Index, markLocalVariableUsed)
|
|
if !ok {
|
|
return nil, nil, nil, false
|
|
}
|
|
stmts = append(stmts, ss...)
|
|
|
|
if len(exprs) != 1 {
|
|
cs.addError(e.Pos(), fmt.Sprintf("multiple-value context is not available at an index expression"))
|
|
return nil, nil, nil, false
|
|
}
|
|
idx := exprs[0]
|
|
if idx.Type == shaderir.NumberExpr {
|
|
if !canTruncateToInteger(idx.Const) {
|
|
cs.addError(e.Pos(), fmt.Sprintf("constant %s truncated to integer", idx.Const.String()))
|
|
return nil, nil, nil, false
|
|
}
|
|
idx.ConstType = shaderir.ConstTypeInt
|
|
}
|
|
|
|
exprs, ts, ss, ok := cs.parseExpr(block, e.X, markLocalVariableUsed)
|
|
if !ok {
|
|
return nil, nil, nil, false
|
|
}
|
|
stmts = append(stmts, ss...)
|
|
if len(exprs) != 1 {
|
|
cs.addError(e.Pos(), fmt.Sprintf("multiple-value context is not available at an index expression"))
|
|
return nil, nil, nil, false
|
|
}
|
|
x := exprs[0]
|
|
t := ts[0]
|
|
|
|
var typ shaderir.Type
|
|
switch t.Main {
|
|
case shaderir.Vec2, shaderir.Vec3, shaderir.Vec4:
|
|
typ = shaderir.Type{Main: shaderir.Float}
|
|
case shaderir.Mat2:
|
|
typ = shaderir.Type{Main: shaderir.Vec2}
|
|
case shaderir.Mat3:
|
|
typ = shaderir.Type{Main: shaderir.Vec3}
|
|
case shaderir.Mat4:
|
|
typ = shaderir.Type{Main: shaderir.Vec4}
|
|
case shaderir.Array:
|
|
typ = t.Sub[0]
|
|
default:
|
|
cs.addError(e.Pos(), fmt.Sprintf("index operator cannot be applied to the type %s", t.String()))
|
|
return nil, nil, nil, false
|
|
}
|
|
|
|
return []shaderir.Expr{
|
|
{
|
|
Type: shaderir.Index,
|
|
Exprs: []shaderir.Expr{
|
|
x,
|
|
idx,
|
|
},
|
|
},
|
|
}, []shaderir.Type{typ}, stmts, true
|
|
|
|
default:
|
|
cs.addError(e.Pos(), fmt.Sprintf("expression not implemented: %#v", e))
|
|
}
|
|
return nil, nil, nil, false
|
|
}
|