Add shaderir

internal/shaderir/glsl.go

@@ -0,0 +1,71 @@
+// 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
+
+import (
+	"fmt"
+	"strings"
+)
+
+func (p *Program) structName(t *Type) string {
+	if t.MainType != Struct {
+		panic("shaderir: the given type at structName must be a struct")
+	}
+	s := t.serialize()
+	if n, ok := p.structNames[s]; ok {
+		return n
+	}
+	n := fmt.Sprintf("S%d", len(p.structNames))
+	p.structNames[s] = n
+	p.structTypes = append(p.structTypes, *t)
+	return n
+}
+
+func (p *Program) Glsl() string {
+	p.structNames = map[string]string{}
+	p.structTypes = nil
+
+	var lines []string
+	for _, u := range p.Uniforms {
+		lines = append(lines, fmt.Sprintf("uniform %s;", p.glslVarDecl(&u.Type, u.Name)))
+	}
+
+	var stLines []string
+	for i, t := range p.structTypes {
+		stLines = append(stLines, fmt.Sprintf("struct S%d {", i))
+		for j, st := range t.SubTypes {
+			stLines = append(stLines, fmt.Sprintf("\t%s;", p.glslVarDecl(&st, fmt.Sprintf("M%d", j))))
+		}
+		stLines = append(stLines, "};")
+	}
+	lines = append(stLines, lines...)
+
+	return strings.Join(lines, "\n") + "\n"
+}
+
+func (p *Program) glslVarDecl(t *Type, varname string) string {
+	switch t.MainType {
+	case None:
+		return "?(none)"
+	case Image2D:
+		panic("not implemented")
+	case Array:
+		return fmt.Sprintf("")
+	case Struct:
+		return fmt.Sprintf("%s %s", p.structName(t), varname)
+	default:
+		return fmt.Sprintf("%s %s", t.MainType.Glsl(), varname)
+	}
+}

internal/shaderir/ir_test.go

@@ -0,0 +1,74 @@
+// 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_test
+
+import (
+	"testing"
+
+	. "github.com/hajimehoshi/ebiten/internal/shaderir"
+)
+
+func TestOutput(t *testing.T) {
+	tests := []struct {
+		Name    string
+		Program Program
+		Glsl    string
+	}{
+		{
+			Name:    "Empty",
+			Program: Program{},
+			Glsl:    ``,
+		},
+		{
+			Name: "Uniform",
+			Program: Program{
+				Uniforms: []Variable{
+					{
+						Name: "U1",
+						Type: Type{MainType: Float},
+					},
+				},
+			},
+			Glsl: `uniform float U1;`,
+		},
+		{
+			Name: "UniformStruct",
+			Program: Program{
+				Uniforms: []Variable{
+					{
+						Name: "U1",
+						Type: Type{
+							MainType: Struct,
+							SubTypes: []Type{
+								{MainType: Float},
+							},
+						},
+					},
+				},
+			},
+			Glsl: `struct S0 {
+	float M0;
+};
+uniform S0 U1;`,
+		},
+	}
+	for _, tc := range tests {
+		got := tc.Program.Glsl()
+		want := tc.Glsl + "\n"
+		if got != want {
+			t.Errorf("%s: got: %s, want: %s", tc.Name, got, want)
+		}
+	}
+}

internal/shaderir/program.go

@@ -0,0 +1,111 @@
+// 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
+
+type Program struct {
+	Uniforms      []Variable
+	Attributes    []Variable
+	Varyings      []Variable
+	Funcs         []Func
+	VertexEntry   string
+	FragmentEntry string
+
+	structNames map[string]string
+	structTypes []Type
+}
+
+type Variable struct {
+	Name string
+	Type Type
+}
+
+type Func struct {
+	Name      string
+	InParams  []Type
+	OutParams []Type
+	Block     Block
+}
+
+type Block struct {
+	LocalVars []Type
+	Stmts     []Stmt
+}
+
+type Stmt struct {
+	Type      StmtType
+	Exprs     []Expr
+	Condition Expr
+	ElseStmts []Expr
+	ForInit   Expr
+	ForRest   Expr
+}
+
+type StmtType int
+
+const (
+	ExprStmt StmtType = iota
+	Assign
+	If
+	For
+	Continue
+	Break
+	Return
+	Discard
+)
+
+type Expr struct {
+	Type  ExprType
+	Exprs []Expr
+	Value string
+	Op    Op
+}
+
+type ExprType int
+
+const (
+	Literal ExprType = iota
+	Ident
+	LocalVarID
+	Unary
+	Binary
+	Call
+	Selector
+	Index
+)
+
+type Op string
+
+const (
+	Add    Op = "+"
+	Sub    Op = "-"
+	Neg    Op = "!"
+	Mul    Op = "*"
+	Div    Op = "/"
+	Mod    Op = "%"
+	LShift Op = "<<"
+	RShift Op = ">>"
+	LT     Op = "<"
+	LE     Op = "<="
+	GT     Op = ">"
+	GE     Op = ">="
+	Eq     Op = "=="
+	NE     Op = "!="
+	And    Op = "&"
+	Xor    Op = "^"
+	Or     Op = "|"
+	AndAnd Op = "&&"
+	OrOr   Op = "||"
+	Cond   Op = "?:"
+)

internal/shaderir/type.go

@@ -0,0 +1,113 @@
+// 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
+
+import (
+	"fmt"
+	"strings"
+)
+
+type Type struct {
+	MainType BasicType
+	SubTypes []Type
+	Length   int
+}
+
+func (t *Type) serialize() string {
+	switch t.MainType {
+	case None:
+		return "none"
+	case Bool:
+		return "bool"
+	case Float:
+		return "float"
+	case Vec2:
+		return "vec2"
+	case Vec3:
+		return "vec3"
+	case Vec4:
+		return "vec4"
+	case Mat2:
+		return "mat2"
+	case Mat3:
+		return "mat3"
+	case Mat4:
+		return "mat4"
+	case Image2D:
+		return "image2d"
+	case Array:
+		return fmt.Sprintf("%s[%d]", t.SubTypes[0].serialize(), t.Length)
+	case Struct:
+		str := "struct{"
+		sub := make([]string, 0, len(t.SubTypes))
+		for _, st := range t.SubTypes {
+			sub = append(sub, st.serialize())
+		}
+		str += strings.Join(sub, ",")
+		str += "}"
+		return str
+	default:
+		return fmt.Sprintf("?(unknown type: %d)", t)
+	}
+}
+
+type BasicType int
+
+const (
+	None BasicType = iota
+	Bool
+	Float
+	Vec2
+	Vec3
+	Vec4
+	Mat2
+	Mat3
+	Mat4
+	Image2D
+	Array
+	Struct
+)
+
+func (t BasicType) Glsl() string {
+	switch t {
+	case None:
+		return "?(none)"
+	case Bool:
+		return "bool"
+	case Float:
+		return "float"
+	case Vec2:
+		return "vec2"
+	case Vec3:
+		return "vec3"
+	case Vec4:
+		return "vec4"
+	case Mat2:
+		return "mat2"
+	case Mat3:
+		return "mat3"
+	case Mat4:
+		return "mat4"
+	case Image2D:
+		return "?(image2d)"
+	case Array:
+		// First-class array is not available on GLSL ES 2.
+		return "?(array)"
+	case Struct:
+		return "?(struct)"
+	default:
+		return fmt.Sprintf("?(unknown type: %d)", t)
+	}
+}