Merge 359e7b8597 into 4b1c0526a7

Closes #2827

examples/textinput/main.go

@@ -40,16 +40,9 @@ const (
 )
 
 type TextField struct {
-	bounds         image.Rectangle
-	multilines     bool
-	text           string
-	selectionStart int
-	selectionEnd   int
-	focused        bool
-
-	ch    chan textinput.State
-	end   func()
-	state textinput.State
+	bounds     image.Rectangle
+	multilines bool
+	field      textinput.Field
 }
 
 func NewTextField(bounds image.Rectangle, multilines bool) *TextField {
@@ -63,17 +56,13 @@ func (t *TextField) Contains(x, y int) bool {
 	return image.Pt(x, y).In(t.bounds)
 }
 
-func (t *TextField) SetSelectionStartByCursorPosition(x, y int) (bool, error) {
-	if err := t.cleanUp(); err != nil {
-		return false, err
-	}
+func (t *TextField) SetSelectionStartByCursorPosition(x, y int) bool {
 	idx, ok := t.textIndexByCursorPosition(x, y)
 	if !ok {
-		return false, nil
+		return false
 	}
-	t.selectionStart = idx
-	t.selectionEnd = idx
-	return true, nil
+	t.field.SetSelection(idx, idx)
+	return true
 }
 
 func (t *TextField) textIndexByCursorPosition(x, y int) (int, bool) {
@@ -97,20 +86,21 @@ func (t *TextField) textIndexByCursorPosition(x, y int) (int, bool) {
 	var nlCount int
 	var lineStart int
 	var prevAdvance float64
-	for i, r := range t.text {
+	txt := t.field.Text()
+	for i, r := range txt {
 		var x0, x1 int
-		currentAdvance := text.Advance(t.text[lineStart:i], fontFace)
+		currentAdvance := text.Advance(txt[lineStart:i], fontFace)
 		if lineStart < i {
 			x0 = int((prevAdvance + currentAdvance) / 2)
 		}
 		if r == '\n' {
 			x1 = int(math.MaxInt32)
-		} else if i < len(t.text) {
+		} else if i < len(txt) {
 			nextI := i + 1
-			for !utf8.ValidString(t.text[i:nextI]) {
+			for !utf8.ValidString(txt[i:nextI]) {
 				nextI++
 			}
-			nextAdvance := text.Advance(t.text[lineStart:nextI], fontFace)
+			nextAdvance := text.Advance(txt[lineStart:nextI], fontFace)
 			x1 = int((currentAdvance + nextAdvance) / 2)
 		} else {
 			x1 = int(currentAdvance)
@@ -127,146 +117,86 @@ func (t *TextField) textIndexByCursorPosition(x, y int) (int, bool) {
 		}
 	}
 
-	return len(t.text), true
+	return len(txt), true
 }
 
 func (t *TextField) Focus() {
-	t.focused = true
+	t.field.Focus()
 }
 
 func (t *TextField) Blur() {
-	t.focused = false
-}
-
-func (t *TextField) cleanUp() error {
-	if t.ch != nil {
-		select {
-		case state, ok := <-t.ch:
-			if state.Error != nil {
-				return state.Error
-			}
-			if ok && state.Committed {
-				t.text = t.text[:t.selectionStart] + state.Text + t.text[t.selectionEnd:]
-				t.selectionStart += len(state.Text)
-				t.selectionEnd = t.selectionStart
-				t.state = textinput.State{}
-			}
-			t.state = state
-		default:
-			break
-		}
-	}
-	if t.end != nil {
-		t.end()
-		t.ch = nil
-		t.end = nil
-		t.state = textinput.State{}
-	}
-	return nil
+	t.field.Blur()
 }
 
 func (t *TextField) Update() error {
-	if !t.focused {
-		// If the text field still has a session, read the last state and process it just in case.
-		if err := t.cleanUp(); err != nil {
-			return err
-		}
+	if !t.field.IsFocused() {
 		return nil
 	}
 
-	var processed bool
-
-	// Text inputting can happen multiple times in one tick (1/60[s] by default).
-	// Handle all of them.
-	for {
-		if t.ch == nil {
-			x, y := t.bounds.Min.X, t.bounds.Min.Y
-			cx, cy := t.cursorPos()
-			px, py := textFieldPadding()
-			x += cx + px
-			y += cy + py + int(fontFace.Metrics().HAscent)
-			t.ch, t.end = textinput.Start(x, y)
-			// Start returns nil for non-supported envrionments.
-			if t.ch == nil {
-				return nil
-			}
-		}
-
-	readchar:
-		for {
-			select {
-			case state, ok := <-t.ch:
-				if state.Error != nil {
-					return state.Error
-				}
-				processed = true
-				if !ok {
-					t.ch = nil
-					t.end = nil
-					t.state = textinput.State{}
-					break readchar
-				}
-				if state.Committed {
-					t.text = t.text[:t.selectionStart] + state.Text + t.text[t.selectionEnd:]
-					t.selectionStart += len(state.Text)
-					t.selectionEnd = t.selectionStart
-					t.state = textinput.State{}
-					continue
-				}
-				t.state = state
-			default:
-				break readchar
-			}
-		}
-
-		if t.ch == nil {
-			continue
-		}
-
-		break
+	x, y := t.bounds.Min.X, t.bounds.Min.Y
+	cx, cy := t.cursorPos()
+	px, py := textFieldPadding()
+	x += cx + px
+	y += cy + py + int(fontFace.Metrics().HAscent)
+	handled, err := t.field.HandleInput(x, y)
+	if err != nil {
+		return err
 	}
-
-	if processed {
+	if handled {
 		return nil
 	}
 
 	switch {
 	case inpututil.IsKeyJustPressed(ebiten.KeyEnter):
 		if t.multilines {
-			t.text = t.text[:t.selectionStart] + "\n" + t.text[t.selectionEnd:]
-			t.selectionStart += 1
-			t.selectionEnd = t.selectionStart
+			text := t.field.Text()
+			selectionStart, selectionEnd := t.field.Selection()
+			text = text[:selectionStart] + "\n" + text[selectionEnd:]
+			selectionStart += len("\n")
+			selectionEnd = selectionStart
+			t.field.SetTextAndSelection(text, selectionStart, selectionEnd)
 		}
 	case inpututil.IsKeyJustPressed(ebiten.KeyBackspace):
-		if t.selectionStart > 0 {
+		text := t.field.Text()
+		selectionStart, selectionEnd := t.field.Selection()
+		if selectionStart != selectionEnd {
+			text = text[:selectionStart] + text[selectionEnd:]
+		} else if selectionStart > 0 {
 			// TODO: Remove a grapheme instead of a code point.
-			_, l := utf8.DecodeLastRuneInString(t.text[:t.selectionStart])
-			t.text = t.text[:t.selectionStart-l] + t.text[t.selectionEnd:]
-			t.selectionStart -= l
+			_, l := utf8.DecodeLastRuneInString(text[:selectionStart])
+			text = text[:selectionStart-l] + text[selectionEnd:]
+			selectionStart -= l
 		}
-		t.selectionEnd = t.selectionStart
+		selectionEnd = selectionStart
+		t.field.SetTextAndSelection(text, selectionStart, selectionEnd)
 	case inpututil.IsKeyJustPressed(ebiten.KeyLeft):
-		if t.selectionStart > 0 {
+		text := t.field.Text()
+		selectionStart, _ := t.field.Selection()
+		if selectionStart > 0 {
 			// TODO: Remove a grapheme instead of a code point.
-			_, l := utf8.DecodeLastRuneInString(t.text[:t.selectionStart])
-			t.selectionStart -= l
+			_, l := utf8.DecodeLastRuneInString(text[:selectionStart])
+			selectionStart -= l
 		}
-		t.selectionEnd = t.selectionStart
+		t.field.SetTextAndSelection(text, selectionStart, selectionStart)
 	case inpututil.IsKeyJustPressed(ebiten.KeyRight):
-		if t.selectionEnd < len(t.text) {
+		text := t.field.Text()
+		_, selectionEnd := t.field.Selection()
+		if selectionEnd < len(text) {
 			// TODO: Remove a grapheme instead of a code point.
-			_, l := utf8.DecodeRuneInString(t.text[t.selectionEnd:])
-			t.selectionEnd += l
+			_, l := utf8.DecodeRuneInString(text[selectionEnd:])
+			selectionEnd += l
 		}
-		t.selectionStart = t.selectionEnd
+		t.field.SetTextAndSelection(text, selectionEnd, selectionEnd)
 	}
 
 	if !t.multilines {
-		orig := t.text
+		orig := t.field.Text()
 		new := strings.ReplaceAll(orig, "\n", "")
 		if new != orig {
-			t.selectionStart -= strings.Count(orig[:t.selectionStart], "\n")
-			t.selectionEnd -= strings.Count(orig[:t.selectionEnd], "\n")
+			selectionStart, selectionEnd := t.field.Selection()
+			selectionStart -= strings.Count(orig[:selectionStart], "\n")
+			selectionEnd -= strings.Count(orig[:selectionEnd], "\n")
+			t.field.SetSelection(selectionStart, selectionEnd)
 		}
 	}
 
@@ -276,17 +206,20 @@ func (t *TextField) Update() error {
 func (t *TextField) cursorPos() (int, int) {
 	var nlCount int
 	lastNLPos := -1
-	for i, r := range t.text[:t.selectionStart] {
+	txt := t.field.TextForRendering()
+	selectionStart, _ := t.field.Selection()
+	if s, _, ok := t.field.CompositionSelection(); ok {
+		selectionStart += s
+	}
+	txt = txt[:selectionStart]
+	for i, r := range txt {
 		if r == '\n' {
 			nlCount++
 			lastNLPos = i
 		}
 	}
 
-	txt := t.text[lastNLPos+1 : t.selectionStart]
-	if t.state.Text != "" {
-		txt += t.state.Text[:t.state.CompositionSelectionStartInBytes]
-	}
+	txt = txt[lastNLPos+1:]
 	x := int(text.Advance(txt, fontFace))
 	y := nlCount * int(fontFace.Metrics().HLineGap+fontFace.Metrics().HAscent+fontFace.Metrics().HDescent)
 	return x, y
@@ -295,13 +228,14 @@ func (t *TextField) cursorPos() (int, int) {
 func (t *TextField) Draw(screen *ebiten.Image) {
 	vector.DrawFilledRect(screen, float32(t.bounds.Min.X), float32(t.bounds.Min.Y), float32(t.bounds.Dx()), float32(t.bounds.Dy()), color.White, false)
 	var clr color.Color = color.Black
-	if t.focused {
+	if t.field.IsFocused() {
 		clr = color.RGBA{0, 0, 0xff, 0xff}
 	}
 	vector.StrokeRect(screen, float32(t.bounds.Min.X), float32(t.bounds.Min.Y), float32(t.bounds.Dx()), float32(t.bounds.Dy()), 1, clr, false)
 
 	px, py := textFieldPadding()
-	if t.focused && t.selectionStart >= 0 {
+	selectionStart, _ := t.field.Selection()
+	if t.field.IsFocused() && selectionStart >= 0 {
 		x, y := t.bounds.Min.X, t.bounds.Min.Y
 		cx, cy := t.cursorPos()
 		x += px + cx
@@ -310,18 +244,13 @@ func (t *TextField) Draw(screen *ebiten.Image) {
 		vector.StrokeLine(screen, float32(x), float32(y), float32(x), float32(y+h), 1, color.Black, false)
 	}
 
-	shownText := t.text
-	if t.focused && t.state.Text != "" {
-		shownText = t.text[:t.selectionStart] + t.state.Text + t.text[t.selectionEnd:]
-	}
-
 	tx := t.bounds.Min.X + px
 	ty := t.bounds.Min.Y + py
 	op := &text.DrawOptions{}
 	op.GeoM.Translate(float64(tx), float64(ty))
 	op.ColorScale.ScaleWithColor(color.Black)
 	op.LineSpacing = fontFace.Metrics().HLineGap + fontFace.Metrics().HAscent + fontFace.Metrics().HDescent
-	text.Draw(screen, shownText, fontFace, op)
+	text.Draw(screen, t.field.TextForRendering(), fontFace, op)
 }
 
 const textFieldHeight = 24
@@ -353,9 +282,7 @@ func (g *Game) Update() error {
 		for _, tf := range g.textFields {
 			if tf.Contains(x, y) {
 				tf.Focus()
-				if _, err := tf.SetSelectionStartByCursorPosition(x, y); err != nil {
-					return err
-				}
+				tf.SetSelectionStartByCursorPosition(x, y)
 			} else {
 				tf.Blur()
 			}

exp/textinput/field.go

@@ -0,0 +1,246 @@
+// Copyright 2024 The Ebitengine 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 textinput
+
+import (
+	"sync"
+)
+
+var (
+	theFocusedField  *Field
+	theFocusedFieldM sync.Mutex
+)
+
+func focusField(f *Field) {
+	var origField *Field
+	defer func() {
+		if origField != nil {
+			origField.cleanUp()
+		}
+	}()
+
+	theFocusedFieldM.Lock()
+	defer theFocusedFieldM.Unlock()
+	if theFocusedField == f {
+		return
+	}
+	origField = theFocusedField
+	theFocusedField = f
+}
+
+func blurField(f *Field) {
+	var origField *Field
+	defer func() {
+		if origField != nil {
+			origField.cleanUp()
+		}
+	}()
+
+	theFocusedFieldM.Lock()
+	defer theFocusedFieldM.Unlock()
+	if theFocusedField != f {
+		return
+	}
+	origField = theFocusedField
+	theFocusedField = nil
+}
+
+func isFieldFocused(f *Field) bool {
+	theFocusedFieldM.Lock()
+	defer theFocusedFieldM.Unlock()
+	return theFocusedField == f
+}
+
+// Field is a region accepting text inputting with IME.
+//
+// Field is not focused by default. You have to call Focus when you start text inputting.
+//
+// Field is a wrapper of the low-level API like Start.
+//
+// For an actual usage, see the examples "textinput".
+type Field struct {
+	text           string
+	selectionStart int
+	selectionEnd   int
+
+	ch    chan State
+	end   func()
+	state State
+	err   error
+}
+
+// HandleInput updates the field state.
+// HandleInput must be called every tick, i.e., every HandleInput, when Field is focused.
+// HandleInput takes a position where an IME window is shown if needed.
+//
+// HandleInput returns whether the text inputting is handled or not.
+// If HandleInput returns true, a Field user should not handle further input events.
+//
+// HandleInput returns an error when handling input causes an error.
+func (f *Field) HandleInput(x, y int) (handled bool, err error) {
+	if f.err != nil {
+		return false, f.err
+	}
+	if !f.IsFocused() {
+		return false, nil
+	}
+
+	// Text inputting can happen multiple times in one tick (1/60[s] by default).
+	// Handle all of them.
+	for {
+		if f.ch == nil {
+			// TODO: On iOS Safari, Start doesn't work as expected (#2898).
+			// Handle a click event and focus the textarea there.
+			f.ch, f.end = Start(x, y)
+			// Start returns nil for non-supported envrionments.
+			if f.ch == nil {
+				return true, nil
+			}
+		}
+
+	readchar:
+		for {
+			select {
+			case state, ok := <-f.ch:
+				if state.Error != nil {
+					f.err = state.Error
+					return false, f.err
+				}
+				handled = true
+				if !ok {
+					f.ch = nil
+					f.end = nil
+					f.state = State{}
+					break readchar
+				}
+				if state.Committed {
+					f.text = f.text[:f.selectionStart] + state.Text + f.text[f.selectionEnd:]
+					f.selectionStart += len(state.Text)
+					f.selectionEnd = f.selectionStart
+					f.state = State{}
+					continue
+				}
+				f.state = state
+			default:
+				break readchar
+			}
+		}
+
+		if f.ch == nil {
+			continue
+		}
+
+		break
+	}
+
+	return
+}
+
+// Focus focuses the field.
+// A Field has to be focused to start text inputting.
+//
+// There can be only one Field that is focused at the same time.
+// When Focus is called and there is already a focused field, Focus removes the focus of that.
+func (f *Field) Focus() {
+	focusField(f)
+}
+
+// Blur removes the focus from the field.
+func (f *Field) Blur() {
+	blurField(f)
+}
+
+// IsFocused reports whether the field is focused or not.
+func (f *Field) IsFocused() bool {
+	return isFieldFocused(f)
+}
+
+func (f *Field) cleanUp() {
+	if f.err != nil {
+		return
+	}
+
+	// If the text field still has a session, read the last state and process it just in case.
+	if f.ch != nil {
+		select {
+		case state, ok := <-f.ch:
+			if state.Error != nil {
+				f.err = state.Error
+				return
+			}
+			if ok && state.Committed {
+				f.text = f.text[:f.selectionStart] + state.Text + f.text[f.selectionEnd:]
+				f.selectionStart += len(state.Text)
+				f.selectionEnd = f.selectionStart
+				f.state = State{}
+			}
+			f.state = state
+		default:
+			break
+		}
+	}
+
+	if f.end != nil {
+		f.end()
+		f.ch = nil
+		f.end = nil
+		f.state = State{}
+	}
+}
+
+// Selection returns the current selection range in bytes.
+func (f *Field) Selection() (start, end int) {
+	return f.selectionStart, f.selectionEnd
+}
+
+// CompositionSelection returns the current composition selection in bytes if a text is composited.
+// If a text is not composited, this returns 0s and false.
+// The returned values indicate relative positions in bytes where the current composition text's start is 0.
+func (f *Field) CompositionSelection() (start, end int, ok bool) {
+	if f.IsFocused() && f.state.Text != "" {
+		return f.state.CompositionSelectionStartInBytes, f.state.CompositionSelectionEndInBytes, true
+	}
+	return 0, 0, false
+}
+
+// SetSelection sets the selection range.
+func (f *Field) SetSelection(start, end int) {
+	f.cleanUp()
+	f.selectionStart = start
+	f.selectionEnd = end
+}
+
+// Text returns the current text.
+// The returned value doesn't include compositing texts.
+func (f *Field) Text() string {
+	return f.text
+}
+
+// TextForRendering returns the text for rendering.
+// The returned value includes compositing texts.
+func (f *Field) TextForRendering() string {
+	if f.IsFocused() && f.state.Text != "" {
+		return f.text[:f.selectionStart] + f.state.Text + f.text[f.selectionEnd:]
+	}
+	return f.text
+}
+
+// SetTextAndSelection sets the text and the selection range.
+func (f *Field) SetTextAndSelection(text string, selectionStart, selectionEnd int) {
+	f.cleanUp()
+	f.text = text
+	f.selectionStart = selectionStart
+	f.selectionEnd = selectionEnd
+}

exp/textinput/textinput.go

@@ -25,6 +25,8 @@ import (
 )
 
 // State represents the current state of text inputting.
+//
+// State is the low-level API. For most use cases, Field is easier to use.
 type State struct {
 	// Text represents the current inputting text.
 	Text string
@@ -45,6 +47,8 @@ type State struct {
 // Start starts text inputting.
 // Start returns a channel to send the state repeatedly, and a function to end the text inputting.
 //
+// Start is the low-leve API. For most use cases, Field is easier to use.
+//
 // Start returns nil and nil if the current environment doesn't support this package.
 func Start(x, y int) (states chan State, close func()) {
 	cx, cy := ui.Get().LogicalPositionToClientPositionInNativePixels(float64(x), float64(y))

internal/shader/delayed.go

@@ -0,0 +1,165 @@
+// Copyright 2024 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 shader
+
+import (
+	"fmt"
+	gconstant "go/constant"
+
+	"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
+)
+
+type delayedTypeValidator interface {
+	Validate(t shaderir.Type) (shaderir.Type, bool)
+	IsValidated() (shaderir.Type, bool)
+	Error() string
+}
+
+func isArgDefaultTypeInt(f shaderir.BuiltinFunc) bool {
+	return f == shaderir.IntF || f == shaderir.IVec2F || f == shaderir.IVec3F || f == shaderir.IVec4F
+}
+
+func isIntType(t shaderir.Type) bool {
+	return t.Main == shaderir.Int || t.IsIntVector()
+}
+
+func (cs *compileState) ValidateDefaultTypesForExpr(block *block, expr shaderir.Expr, t shaderir.Type) shaderir.Type {
+	if check, ok := cs.delayedTypeCheks[expr.Ast]; ok {
+		if resT, ok := check.IsValidated(); ok {
+			return resT
+		}
+		resT, ok := check.Validate(t)
+		if !ok {
+			return shaderir.Type{Main: shaderir.None}
+		}
+		return resT
+	}
+
+	switch expr.Type {
+	case shaderir.LocalVariable:
+		return block.vars[expr.Index].typ
+
+	case shaderir.Binary:
+		left := expr.Exprs[0]
+		right := expr.Exprs[1]
+
+		leftType := cs.ValidateDefaultTypesForExpr(block, left, t)
+		rightType := cs.ValidateDefaultTypesForExpr(block, right, t)
+
+		// Usure about top-level type, try to validate by neighbour type
+		// The same work is done twice. Can it be optimized?
+		if t.Main == shaderir.None {
+			cs.ValidateDefaultTypesForExpr(block, left, rightType)
+			cs.ValidateDefaultTypesForExpr(block, right, leftType)
+		}
+	case shaderir.Call:
+		fun := expr.Exprs[0]
+		if fun.Type == shaderir.BuiltinFuncExpr {
+			if isArgDefaultTypeInt(fun.BuiltinFunc) {
+				for _, e := range expr.Exprs[1:] {
+					cs.ValidateDefaultTypesForExpr(block, e, shaderir.Type{Main: shaderir.Int})
+				}
+				return shaderir.Type{Main: shaderir.Int}
+			}
+
+			for _, e := range expr.Exprs[1:] {
+				cs.ValidateDefaultTypesForExpr(block, e, shaderir.Type{Main: shaderir.Float})
+			}
+			return shaderir.Type{Main: shaderir.Float}
+		}
+
+		if fun.Type == shaderir.FunctionExpr {
+			args := cs.funcs[fun.Index].ir.InParams
+
+			for i, e := range expr.Exprs[1:] {
+				cs.ValidateDefaultTypesForExpr(block, e, args[i])
+			}
+
+			retT := cs.funcs[fun.Index].ir.Return
+
+			return retT
+		}
+	}
+
+	return shaderir.Type{Main: shaderir.None}
+}
+
+func (cs *compileState) ValidateDefaultTypes(block *block, stmt shaderir.Stmt) {
+	switch stmt.Type {
+	case shaderir.Assign:
+		left := stmt.Exprs[0]
+		right := stmt.Exprs[1]
+		if left.Type == shaderir.LocalVariable {
+			varType := block.vars[left.Index].typ
+			// Type is not explicitly specified
+			if stmt.IsTypeGuessed {
+				varType = shaderir.Type{Main: shaderir.None}
+			}
+			cs.ValidateDefaultTypesForExpr(block, right, varType)
+		}
+	case shaderir.ExprStmt:
+		for _, e := range stmt.Exprs {
+			cs.ValidateDefaultTypesForExpr(block, e, shaderir.Type{Main: shaderir.None})
+		}
+	}
+}
+
+type delayedShiftValidator struct {
+	shiftType      shaderir.Op
+	value          gconstant.Value
+	validated      bool
+	closestUnknown bool
+	failed         bool
+}
+
+func (d *delayedShiftValidator) IsValidated() (shaderir.Type, bool) {
+	if d.failed {
+		return shaderir.Type{}, false
+	}
+	if d.validated {
+		return shaderir.Type{Main: shaderir.Int}, true
+	}
+	// If only matched with None
+	if d.closestUnknown {
+		// Was it originally represented by an int constant?
+		if d.value.Kind() == gconstant.Int {
+			return shaderir.Type{Main: shaderir.Int}, true
+		}
+	}
+	return shaderir.Type{}, false
+}
+
+func (d *delayedShiftValidator) Validate(t shaderir.Type) (shaderir.Type, bool) {
+	if d.validated {
+		return shaderir.Type{Main: shaderir.Int}, true
+	}
+	if isIntType(t) {
+		d.validated = true
+		return shaderir.Type{Main: shaderir.Int}, true
+	}
+	if t.Main == shaderir.None {
+		d.closestUnknown = true
+		return t, true
+	}
+	return shaderir.Type{Main: shaderir.None}, false
+}
+
+func (d *delayedShiftValidator) Error() string {
+	st := "left shift"
+	if d.shiftType == shaderir.RightShift {
+		st = "right shift"
+	}
+	return fmt.Sprintf("left operand for %s should be int", st)
+}

internal/shader/expr.go

@@ -36,7 +36,7 @@ func canTruncateToFloat(v gconstant.Value) bool {
 
 var textureVariableRe = regexp.MustCompile(`\A__t(\d+)\z`)
 
-func (cs *compileState) parseExpr(block *block, fname string, expr ast.Expr, markLocalVariableUsed bool) ([]shaderir.Expr, []shaderir.Type, []shaderir.Stmt, bool) {
+func (cs *compileState) parseExpr(block *block, fname string, expr ast.Expr, markLocalVariableUsed bool) (rexpr []shaderir.Expr, rtype []shaderir.Type, rstmt []shaderir.Stmt, ok bool) {
 	switch e := expr.(type) {
 	case *ast.BasicLit:
 		switch e.Kind {
@@ -105,7 +105,14 @@ func (cs *compileState) parseExpr(block *block, fname string, expr ast.Expr, mar
 		}
 
 		// Resolve untyped constants.
-		l, r, ok := shaderir.ResolveUntypedConstsForBinaryOp(lhs[0].Const, rhs[0].Const, lhst, rhst)
+		var l gconstant.Value
+		var r gconstant.Value
+		origLvalue := lhs[0].Const
+		if op2 == shaderir.LeftShift || op2 == shaderir.RightShift {
+			l, r, ok = shaderir.ResolveUntypedConstsForBitShiftOp(lhs[0].Const, rhs[0].Const, lhst, rhst)
+		} else {
+			l, r, ok = shaderir.ResolveUntypedConstsForBinaryOp(lhs[0].Const, rhs[0].Const, lhst, rhst)
+		}
 		if !ok {
 			// TODO: Show a better type name for untyped constants.
 			cs.addError(e.Pos(), fmt.Sprintf("types don't match: %s %s %s", lhst.String(), op, rhst.String()))
@@ -113,27 +120,49 @@ func (cs *compileState) parseExpr(block *block, fname string, expr ast.Expr, mar
 		}
 		lhs[0].Const, rhs[0].Const = l, r
 
-		// If either is typed, resolve the other type.
-		// If both are untyped, keep them untyped.
-		if lhst.Main != shaderir.None || rhst.Main != shaderir.None {
-			if lhs[0].Const != nil {
-				switch lhs[0].Const.Kind() {
-				case gconstant.Float:
-					lhst = shaderir.Type{Main: shaderir.Float}
-				case gconstant.Int:
+		if op2 == shaderir.LeftShift || op2 == shaderir.RightShift {
+			if !(lhst.Main == shaderir.None && rhst.Main == shaderir.None) {
+				// If both are const
+				if rhs[0].Const != nil && (rhst.Main == shaderir.None || lhs[0].Const != nil) {
+					rhst = shaderir.Type{Main: shaderir.Int}
+				}
+
+				// If left is untyped const
+				if lhst.Main == shaderir.None && lhs[0].Const != nil {
 					lhst = shaderir.Type{Main: shaderir.Int}
-				case gconstant.Bool:
-					lhst = shaderir.Type{Main: shaderir.Bool}
+					// Left should be implicitly converted to the type it would assume if the shift expression were replaced by its left operand alone.
+					if rhs[0].Const == nil {
+						defer func() {
+							if ok {
+								cs.addDelayedTypeCheck(expr, &delayedShiftValidator{value: origLvalue})
+							}
+						}()
+					}
 				}
 			}
-			if rhs[0].Const != nil {
-				switch rhs[0].Const.Kind() {
-				case gconstant.Float:
-					rhst = shaderir.Type{Main: shaderir.Float}
-				case gconstant.Int:
-					rhst = shaderir.Type{Main: shaderir.Int}
-				case gconstant.Bool:
-					rhst = shaderir.Type{Main: shaderir.Bool}
+		} else {
+			// If either is typed, resolve the other type.
+			// If both are untyped, keep them untyped.
+			if lhst.Main != shaderir.None || rhst.Main != shaderir.None {
+				if lhs[0].Const != nil {
+					switch lhs[0].Const.Kind() {
+					case gconstant.Float:
+						lhst = shaderir.Type{Main: shaderir.Float}
+					case gconstant.Int:
+						lhst = shaderir.Type{Main: shaderir.Int}
+					case gconstant.Bool:
+						lhst = shaderir.Type{Main: shaderir.Bool}
+					}
+				}
+				if rhs[0].Const != nil {
+					switch rhs[0].Const.Kind() {
+					case gconstant.Float:
+						rhst = shaderir.Type{Main: shaderir.Float}
+					case gconstant.Int:
+						rhst = shaderir.Type{Main: shaderir.Int}
+					case gconstant.Bool:
+						rhst = shaderir.Type{Main: shaderir.Bool}
+					}
 				}
 			}
 		}
@@ -153,6 +182,13 @@ func (cs *compileState) parseExpr(block *block, fname string, expr ast.Expr, mar
 				v = gconstant.MakeBool(b)
 			case token.EQL, token.NEQ, token.LSS, token.LEQ, token.GTR, token.GEQ:
 				v = gconstant.MakeBool(gconstant.Compare(lhs[0].Const, op, rhs[0].Const))
+			case token.SHL, token.SHR:
+				shift, ok := gconstant.Int64Val(rhs[0].Const)
+				if !ok {
+					cs.addError(e.Pos(), fmt.Sprintf("unexpected %s type for: %s", rhs[0].Const.String(), e.Op))
+				} else {
+					v = gconstant.Shift(lhs[0].Const, op, uint(shift))
+				}
 			default:
 				v = gconstant.BinaryOp(lhs[0].Const, op, rhs[0].Const)
 			}
@@ -169,6 +205,7 @@ func (cs *compileState) parseExpr(block *block, fname string, expr ast.Expr, mar
 			{
 				Type:  shaderir.Binary,
 				Op:    op2,
+				Ast:   expr,
 				Exprs: []shaderir.Expr{lhs[0], rhs[0]},
 			},
 		}, []shaderir.Type{t}, stmts, true

internal/shader/shader.go

@@ -61,6 +61,8 @@ type compileState struct {
 
 	varyingParsed bool
 
+	delayedTypeCheks map[ast.Expr]delayedTypeValidator
+
 	errs []string
 }
 
@@ -82,6 +84,13 @@ func (cs *compileState) findUniformVariable(name string) (int, bool) {
 	return 0, false
 }
 
+func (cs *compileState) addDelayedTypeCheck(at ast.Expr, check delayedTypeValidator) {
+	if cs.delayedTypeCheks == nil {
+		cs.delayedTypeCheks = make(map[ast.Expr]delayedTypeValidator, 1)
+	}
+	cs.delayedTypeCheks[at] = check
+}
+
 type typ struct {
 	name string
 	ir   shaderir.Type

internal/shader/stmt.go

@@ -49,6 +49,10 @@ func (cs *compileState) parseStmt(block *block, fname string, stmt ast.Stmt, inP
 			if !ok {
 				return nil, false
 			}
+			for i := range ss {
+				ss[i].IsTypeGuessed = true
+			}
+
 			stmts = append(stmts, ss...)
 		case token.ASSIGN:
 			if len(stmt.Lhs) != len(stmt.Rhs) && len(stmt.Rhs) != 1 {
@@ -60,7 +64,7 @@ func (cs *compileState) parseStmt(block *block, fname string, stmt ast.Stmt, inP
 				return nil, false
 			}
 			stmts = append(stmts, ss...)
-		case token.ADD_ASSIGN, token.SUB_ASSIGN, token.MUL_ASSIGN, token.QUO_ASSIGN, token.REM_ASSIGN, token.AND_ASSIGN, token.OR_ASSIGN, token.XOR_ASSIGN, token.AND_NOT_ASSIGN:
+		case token.ADD_ASSIGN, token.SUB_ASSIGN, token.MUL_ASSIGN, token.QUO_ASSIGN, token.REM_ASSIGN, token.AND_ASSIGN, token.OR_ASSIGN, token.XOR_ASSIGN, token.AND_NOT_ASSIGN, token.SHL_ASSIGN, token.SHR_ASSIGN:
 			rhs, rts, ss, ok := cs.parseExpr(block, fname, stmt.Rhs[0], true)
 			if !ok {
 				return nil, false
@@ -100,6 +104,10 @@ func (cs *compileState) parseStmt(block *block, fname string, stmt ast.Stmt, inP
 				op = shaderir.Or
 			case token.XOR_ASSIGN:
 				op = shaderir.Xor
+			case token.SHL_ASSIGN:
+				op = shaderir.LeftShift
+			case token.SHR_ASSIGN:
+				op = shaderir.RightShift
 			default:
 				cs.addError(stmt.Pos(), fmt.Sprintf("unexpected token: %s", stmt.Tok))
 				return nil, false
@@ -110,7 +118,7 @@ func (cs *compileState) parseStmt(block *block, fname string, stmt ast.Stmt, inP
 					cs.addError(stmt.Pos(), fmt.Sprintf("invalid operation: operator / not defined on %s", rts[0].String()))
 					return nil, false
 				}
-				if op == shaderir.And || op == shaderir.Or || op == shaderir.Xor {
+				if op == shaderir.And || op == shaderir.Or || op == shaderir.Xor || op == shaderir.LeftShift || op == shaderir.RightShift {
 					if lts[0].Main != shaderir.Int && !lts[0].IsIntVector() {
 						cs.addError(stmt.Pos(), fmt.Sprintf("invalid operation: operator %s not defined on %s", stmt.Tok, lts[0].String()))
 					}
@@ -137,7 +145,7 @@ func (cs *compileState) parseStmt(block *block, fname string, stmt ast.Stmt, inP
 						}
 					}
 				case shaderir.Float:
-					if op == shaderir.And || op == shaderir.Or || op == shaderir.Xor {
+					if op == shaderir.And || op == shaderir.Or || op == shaderir.Xor || op == shaderir.LeftShift || op == shaderir.RightShift {
 						cs.addError(stmt.Pos(), fmt.Sprintf("invalid operation: operator %s not defined on %s", stmt.Tok, lts[0].String()))
 					} else if rhs[0].Const != nil &&
 						(rts[0].Main == shaderir.None || rts[0].Main == shaderir.Float) &&
@@ -148,7 +156,7 @@ func (cs *compileState) parseStmt(block *block, fname string, stmt ast.Stmt, inP
 						return nil, false
 					}
 				case shaderir.Vec2, shaderir.Vec3, shaderir.Vec4, shaderir.Mat2, shaderir.Mat3, shaderir.Mat4:
-					if op == shaderir.And || op == shaderir.Or || op == shaderir.Xor {
+					if op == shaderir.And || op == shaderir.Or || op == shaderir.Xor || op == shaderir.LeftShift || op == shaderir.RightShift {
 						cs.addError(stmt.Pos(), fmt.Sprintf("invalid operation: operator %s not defined on %s", stmt.Tok, lts[0].String()))
 					} else if (op == shaderir.MatrixMul || op == shaderir.Div) &&
 						(rts[0].Main == shaderir.Float ||
@@ -469,6 +477,25 @@ func (cs *compileState) parseStmt(block *block, fname string, stmt ast.Stmt, inP
 		cs.addError(stmt.Pos(), fmt.Sprintf("unexpected statement: %#v", stmt))
 		return nil, false
 	}
+
+	// Need to run delayed checks
+	if len(cs.delayedTypeCheks) != 0 {
+		for _, st := range stmts {
+			cs.ValidateDefaultTypes(block, st)
+		}
+
+		// Collect all errors first
+		foundErr := false
+		for s, v := range cs.delayedTypeCheks {
+			if _, ok := v.IsValidated(); !ok {
+				foundErr = true
+				cs.addError(s.Pos(), v.Error())
+			}
+		}
+		if foundErr {
+			return nil, false
+		}
+	}
 	return stmts, true
 }
 

internal/shader/syntax_test.go

@@ -1314,6 +1314,263 @@ func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
 	}
 }
 
+// Issue: #2755
+func TestSyntaxOperatorShift(t *testing.T) {
+	cases := []struct {
+		stmt string
+		err  bool
+	}{
+		{stmt: "b := 2.0; a := 1.0 << 2.0 == b; _ = a", err: false},
+		{stmt: "s := 1; b := 2.0; a := 1.0<<s == b; _ = a", err: true},
+		{stmt: "s := 1; b := 2; a := 1.0<<s == b; _ = a", err: false},
+		{stmt: "s := 1; a := 2.0<<s + ivec2(3.0<<s); _ = a", err: false},
+		{stmt: "s := 1; a := 2.0<<s + vec2(3); _ = a", err: true},
+		{stmt: "s := 1; a := 2.0<<s + ivec2(3); _ = a", err: false},
+		{stmt: "s := 1; a := 2.0<<s + foo_int_int(3.0<<s); _ = a", err: false},
+		{stmt: "s := 1; a := 2.0<<s + 3.0<<s; _ = a", err: true},
+		{stmt: "s := 1; a := 2<<s + 3.0<<s; _ = a", err: true},
+		{stmt: "s := 1; a := 2.0<<s + 3<<s; _ = a", err: true},
+		{stmt: "s := 1; a := 2<<s + 3<<s; _ = a", err: false},
+		{stmt: "s := 1; foo_multivar(0, 0, 2<<s)", err: false},
+		{stmt: "s := 1; foo_multivar(0, 2.0<<s, 0)", err: true},
+		{stmt: "s := 1; foo_multivar(2.0<<s, 0, 0)", err: false},
+		{stmt: "s := 1; a := foo_multivar(2.0<<s, 0, 0); _ = a", err: false},
+		{stmt: "s := 1; a := foo_multivar(0, 2.0<<s, 0); _ = a", err: true},
+		{stmt: "s := 1; a := foo_multivar(0, 0, 2.0<<s); _ = a", err: false},
+		{stmt: "a := foo_multivar(0, 0, 1.0<<2.0); _ = a", err: false},
+		{stmt: "a := foo_multivar(0, 1.0<<2.0, 0); _ = a", err: false},
+		{stmt: "s := 1; a := int(1) + 1.0<<s + int(float(1<<s)); _ = a", err: true},
+		{stmt: "s := 1; var a int = 1.0 << 2.0 << 3.0 << 4.0 << s; _ = a", err: false},
+		{stmt: "s := 1; var a float = 1 << 1 << 1 << 1 << s; _ = a", err: true},
+		{stmt: "s := 1; var a float = 1 << s + 1.2; _ = a", err: true},
+		{stmt: "s := 1; a := 1.0 << s + 1.2; _ = a", err: true},
+		{stmt: "s := 1; a := 1.0 << s + foo_float_float(2); _ = a", err: true},
+		{stmt: "s := 1; a := 1.0 << s + foo_float_int(2); _ = a", err: false},
+		{stmt: "s := 1; a := foo_float_int(1.0<<s) + foo_float_int(2); _ = a", err: true},
+		{stmt: "s := 1; a := foo_int_float(1<<s) + foo_int_float(2); _ = a", err: false},
+		{stmt: "s := 1; a := foo_int_int(1<<s) + foo_int_int(2); _ = a", err: false},
+		{stmt: "s := 1; t := 2.0; a := t + 1.0 << s; _ = a", err: true},
+		{stmt: "s := 1; t := 2; a := t + 1.0 << s; _ = a", err: false},
+		{stmt: "s := 1; b := 1 << s; _ = b", err: false},
+		{stmt: "var a = 1; b := a << 2.0; _ = b", err: false},
+		{stmt: "s := 1; var a float; a = 1 << s; _ = a", err: true},
+		{stmt: "s := 1; var a float = 1 << s; _ = a", err: true},
+		{stmt: "s := 1; var a float = float(1.0 << s); _ = a", err: true},
+		{stmt: "s := 1; var a int = int(1 << s); _ = a", err: false},
+		{stmt: "s := 1; var a int = int(1.0 << s); _ = a", err: false},
+		{stmt: "s := 1; a := 1 << s; _ = a", err: false},
+		{stmt: "s := 1; a := 1.0 << s; _ = a", err: true},
+		{stmt: "s := 1; a := int(1.0 << s); _ = a", err: false},
+		{stmt: "s := 1; var a float = float(1.0 << s); _ = a", err: true},
+		{stmt: "s := 1; var a float = 1.0 << s; _ = a", err: true},
+		{stmt: "s := 1; var a float = 1 << s; _ = a", err: true},
+		{stmt: "s := 1; var a int = 1.0 << s; _ = a", err: false},
+		{stmt: "s := 1; var a int = 1 << s; _ = a", err: false},
+		{stmt: "var a float = 1.0 << 2.0; _ = a", err: false},
+		{stmt: "var a int = 1.0 << 2; _ = a", err: false},
+		{stmt: "var a float = 1.0 << 2; _ = a", err: false},
+		{stmt: "a := 1 << 2.0; _ = a", err: false},
+		{stmt: "a := 1.0 << 2; _ = a", err: false},
+		{stmt: "a := 1.0 << 2.0; _ = a", err: false},
+		{stmt: "a := 1 << 2; _ = a", err: false},
+		{stmt: "a := float(1.0) << 2; _ = a", err: true},
+		{stmt: "a := 1 << float(2.0); _ = a", err: false},
+		{stmt: "a := 1.0 << float(2.0); _ = a", err: false},
+		{stmt: "a := ivec2(1) << 2; _ = a", err: false},
+		{stmt: "a := 1 << ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1) << float(2.0); _ = a", err: true},
+		{stmt: "a := float(1.0) << ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1) << ivec2(2); _ = a", err: false},
+		{stmt: "a := ivec3(1) << ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1) << ivec3(2); _ = a", err: true},
+		{stmt: "a := 1 << vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1) << 2; _ = a", err: true},
+		{stmt: "a := float(1.0) << vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1) << float(2.0); _ = a", err: true},
+		{stmt: "a := vec2(1) << vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1) << vec3(2); _ = a", err: true},
+		{stmt: "a := vec3(1) << vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1) << ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1) << vec2(2); _ = a", err: true},
+		{stmt: "a := vec3(1) << ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1) << vec3(2); _ = a", err: true},
+
+		{stmt: "b := 2.0; a := 1.0 >> 2.0 == b; _ = a", err: false},
+		{stmt: "s := 1; b := 2.0; a := 1.0>>s == b; _ = a", err: true},
+		{stmt: "s := 1; b := 2; a := 1.0>>s == b; _ = a", err: false},
+		{stmt: "s := 1; a := 2.0>>s + ivec2(3.0>>s); _ = a", err: false},
+		{stmt: "s := 1; a := 2.0>>s + vec2(3); _ = a", err: true},
+		{stmt: "s := 1; a := 2.0>>s + ivec2(3); _ = a", err: false},
+		{stmt: "s := 1; a := 2.0>>s + foo_int_int(3.0>>s); _ = a", err: false},
+		{stmt: "s := 1; a := 2.0>>s + 3.0>>s; _ = a", err: true},
+		{stmt: "s := 1; a := 2>>s + 3.0>>s; _ = a", err: true},
+		{stmt: "s := 1; a := 2.0>>s + 3>>s; _ = a", err: true},
+		{stmt: "s := 1; a := 2>>s + 3>>s; _ = a", err: false},
+		{stmt: "s := 1; foo_multivar(0, 0, 2>>s)", err: false},
+		{stmt: "s := 1; foo_multivar(0, 2.0>>s, 0)", err: true},
+		{stmt: "s := 1; foo_multivar(2.0>>s, 0, 0)", err: false},
+		{stmt: "s := 1; a := foo_multivar(2.0>>s, 0, 0); _ = a", err: false},
+		{stmt: "s := 1; a := foo_multivar(0, 2.0>>s, 0); _ = a", err: true},
+		{stmt: "s := 1; a := foo_multivar(0, 0, 2.0>>s); _ = a", err: false},
+		{stmt: "a := foo_multivar(0, 0, 1.0>>2.0); _ = a", err: false},
+		{stmt: "a := foo_multivar(0, 1.0>>2.0, 0); _ = a", err: false},
+		{stmt: "s := 1; a := int(1) + 1.0>>s + int(float(1>>s)); _ = a", err: true},
+		{stmt: "s := 1; var a int = 1.0 >> 2.0 >> 3.0 >> 4.0 >> s; _ = a", err: false},
+		{stmt: "s := 1; var a float = 1 >> 1 >> 1 >> 1 >> s; _ = a", err: true},
+		{stmt: "s := 1; var a float = 1 >> s + 1.2; _ = a", err: true},
+		{stmt: "s := 1; a := 1.0 >> s + 1.2; _ = a", err: true},
+		{stmt: "s := 1; a := 1.0 >> s + foo_float_float(2); _ = a", err: true},
+		{stmt: "s := 1; a := 1.0 >> s + foo_float_int(2); _ = a", err: false},
+		{stmt: "s := 1; a := foo_float_int(1.0>>s) + foo_float_int(2); _ = a", err: true},
+		{stmt: "s := 1; a := foo_int_float(1>>s) + foo_int_float(2); _ = a", err: false},
+		{stmt: "s := 1; a := foo_int_int(1>>s) + foo_int_int(2); _ = a", err: false},
+		{stmt: "s := 1; t := 2.0; a := t + 1.0 >> s; _ = a", err: true},
+		{stmt: "s := 1; t := 2; a := t + 1.0 >> s; _ = a", err: false},
+		{stmt: "s := 1; b := 1 >> s; _ = b", err: false},
+		{stmt: "var a = 1; b := a >> 2.0; _ = b", err: false},
+		{stmt: "s := 1; var a float; a = 1 >> s; _ = a", err: true},
+		{stmt: "s := 1; var a float = 1 >> s; _ = a", err: true},
+		{stmt: "s := 1; var a float = float(1.0 >> s); _ = a", err: true},
+		{stmt: "s := 1; var a int = int(1 >> s); _ = a", err: false},
+		{stmt: "s := 1; var a int = int(1.0 >> s); _ = a", err: false},
+		{stmt: "s := 1; a := 1 >> s; _ = a", err: false},
+		{stmt: "s := 1; a := 1.0 >> s; _ = a", err: true},
+		{stmt: "s := 1; a := int(1.0 >> s); _ = a", err: false},
+		{stmt: "s := 1; var a float = float(1.0 >> s); _ = a", err: true},
+		{stmt: "s := 1; var a float = 1.0 >> s; _ = a", err: true},
+		{stmt: "s := 1; var a float = 1 >> s; _ = a", err: true},
+		{stmt: "s := 1; var a int = 1.0 >> s; _ = a", err: false},
+		{stmt: "s := 1; var a int = 1 >> s; _ = a", err: false},
+		{stmt: "var a float = 1.0 >> 2.0; _ = a", err: false},
+		{stmt: "var a int = 1.0 >> 2; _ = a", err: false},
+		{stmt: "var a float = 1.0 >> 2; _ = a", err: false},
+		{stmt: "a := 1 >> 2.0; _ = a", err: false},
+		{stmt: "a := 1.0 >> 2; _ = a", err: false},
+		{stmt: "a := 1.0 >> 2.0; _ = a", err: false},
+		{stmt: "a := 1 >> 2; _ = a", err: false},
+		{stmt: "a := float(1.0) >> 2; _ = a", err: true},
+		{stmt: "a := 1 >> float(2.0); _ = a", err: false},
+		{stmt: "a := 1.0 >> float(2.0); _ = a", err: false},
+		{stmt: "a := ivec2(1) >> 2; _ = a", err: false},
+		{stmt: "a := 1 >> ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1) >> float(2.0); _ = a", err: true},
+		{stmt: "a := float(1.0) >> ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1) >> ivec2(2); _ = a", err: false},
+		{stmt: "a := ivec3(1) >> ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1) >> ivec3(2); _ = a", err: true},
+		{stmt: "a := 1 >> vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1) >> 2; _ = a", err: true},
+		{stmt: "a := float(1.0) >> vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1) >> float(2.0); _ = a", err: true},
+		{stmt: "a := vec2(1) >> vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1) >> vec3(2); _ = a", err: true},
+		{stmt: "a := vec3(1) >> vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1) >> ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1) >> vec2(2); _ = a", err: true},
+		{stmt: "a := vec3(1) >> ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1) >> vec3(2); _ = a", err: true},
+	}
+
+	for _, c := range cases {
+		_, err := compileToIR([]byte(fmt.Sprintf(`package main
+func foo_multivar(x int, y float, z int) int {return x}
+func foo_int_int(x int) int {return x}
+func foo_float_int(x float) int {return int(x)}
+func foo_int_float(x int) float {return float(x)}
+func foo_float_float(x float) float {return x}
+func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
+	%s
+	return dstPos
+}`, c.stmt)))
+		if err == nil && c.err {
+			t.Errorf("%s must return an error but does not", c.stmt)
+		} else if err != nil && !c.err {
+			t.Errorf("%s must not return nil but returned %v", c.stmt, err)
+		}
+	}
+}
+
+func TestSyntaxOperatorShiftAssign(t *testing.T) {
+	cases := []struct {
+		stmt string
+		err  bool
+	}{
+		{stmt: "a := 1; a <<= 2; _ = a", err: false},
+		{stmt: "a := 1; a <<= 2.0; _ = a", err: false},
+		{stmt: "a := float(1.0); a <<= 2; _ = a", err: true},
+		{stmt: "a := 1; a <<= float(2.0); _ = a", err: true},
+		{stmt: "a := ivec2(1); a <<= 2; _ = a", err: false},
+		{stmt: "a := 1;  a <<= ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1); a <<= float(2.0); _ = a", err: true},
+		{stmt: "a := float(1.0); a <<= ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1); a <<= ivec2(2); _ = a", err: false},
+		{stmt: "a := ivec3(1); a <<= ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1); a <<= ivec3(2); _ = a", err: true},
+		{stmt: "a := 1; a <<= vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1); a <<= 2; _ = a", err: true},
+		{stmt: "a := float(1.0); a <<= vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1); a <<= float(2.0); _ = a", err: true},
+		{stmt: "a := vec2(1); a <<= vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1); a <<= vec3(2); _ = a", err: true},
+		{stmt: "a := vec3(1); a <<= vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1); a <<= ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1); a <<= vec2(2); _ = a", err: true},
+		{stmt: "a := vec3(1); a <<= ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1); a <<= vec3(2); _ = a", err: true},
+		{stmt: "const c = 2; a := 1; a <<= c; _ = a", err: false},
+		{stmt: "const c = 2.0; a := 1; a <<= c; _ = a", err: false},
+		{stmt: "const c = 2; a := float(1.0); a <<= c; _ = a", err: true},
+		{stmt: "const c float = 2; a := 1; a <<= c; _ = a", err: true},
+		{stmt: "const c float = 2.0; a := 1; a <<= c; _ = a", err: true},
+		{stmt: "const c int = 2; a := ivec2(1); a <<= c; _ = a", err: false},
+		{stmt: "const c int = 2; a := vec2(1); a <<= c; _ = a", err: true},
+
+		{stmt: "a := 1; a >>= 2; _ = a", err: false},
+		{stmt: "a := 1; a >>= 2.0; _ = a", err: false},
+		{stmt: "a := float(1.0); a >>= 2; _ = a", err: true},
+		{stmt: "a := 1; a >>= float(2.0); _ = a", err: true},
+		{stmt: "a := ivec2(1); a >>= 2; _ = a", err: false},
+		{stmt: "a := 1;  a >>= ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1); a >>= float(2.0); _ = a", err: true},
+		{stmt: "a := float(1.0); a >>= ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1); a >>= ivec2(2); _ = a", err: false},
+		{stmt: "a := ivec3(1); a >>= ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1); a >>= ivec3(2); _ = a", err: true},
+		{stmt: "a := 1; a >>= vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1); a >>= 2; _ = a", err: true},
+		{stmt: "a := float(1.0); a >>= vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1); a >>= float(2.0); _ = a", err: true},
+		{stmt: "a := vec2(1); a >>= vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1); a >>= vec3(2); _ = a", err: true},
+		{stmt: "a := vec3(1); a >>= vec2(2); _ = a", err: true},
+		{stmt: "a := vec2(1); a >>= ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1); a >>= vec2(2); _ = a", err: true},
+		{stmt: "a := vec3(1); a >>= ivec2(2); _ = a", err: true},
+		{stmt: "a := ivec2(1); a >>= vec3(2); _ = a", err: true},
+		{stmt: "const c = 2; a := 1; a >>= c; _ = a", err: false},
+		{stmt: "const c = 2.0; a := 1; a >>= c; _ = a", err: false},
+		{stmt: "const c = 2; a := float(1.0); a >>= c; _ = a", err: true},
+		{stmt: "const c float = 2; a := 1; a >>= c; _ = a", err: true},
+		{stmt: "const c float = 2.0; a := 1; a >>= c; _ = a", err: true},
+		{stmt: "const c int = 2; a := ivec2(1); a >>= c; _ = a", err: false},
+		{stmt: "const c int = 2; a := vec2(1); a >>= c; _ = a", err: true},
+	}
+
+	for _, c := range cases {
+		_, err := compileToIR([]byte(fmt.Sprintf(`package main
+
+func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
+	%s
+	return dstPos
+}`, c.stmt)))
+		if err == nil && c.err {
+			t.Errorf("%s must return an error but does not", c.stmt)
+		} else if err != nil && !c.err {
+			t.Errorf("%s must not return nil but returned %v", c.stmt, err)
+		}
+	}
+}
+
 // Issue #1971
 func TestSyntaxOperatorMultiplyAssign(t *testing.T) {
 	cases := []struct {

internal/shaderir/check.go

@@ -18,6 +18,29 @@ import (
 	"go/constant"
 )
 
+func ResolveUntypedConstsForBitShiftOp(lhs, rhs constant.Value, lhst, rhst Type) (newLhs, newRhs constant.Value, ok bool) {
+	cLhs := lhs
+	cRhs := rhs
+
+	// Right is const -> int
+	if rhs != nil {
+		cRhs = constant.ToInt(rhs)
+		if cRhs.Kind() == constant.Unknown {
+			return nil, nil, false
+		}
+	}
+
+	// Left if untyped const -> int
+	if lhs != nil && lhst.Main == None {
+		cLhs = constant.ToInt(lhs)
+		if cLhs.Kind() == constant.Unknown {
+			return nil, nil, false
+		}
+	}
+
+	return cLhs, cRhs, true
+}
+
 func ResolveUntypedConstsForBinaryOp(lhs, rhs constant.Value, lhst, rhst Type) (newLhs, newRhs constant.Value, ok bool) {
 	if lhst.Main == None && rhst.Main == None {
 		if lhs.Kind() == rhs.Kind() {
@@ -121,6 +144,16 @@ func TypeFromBinaryOp(op Op, lhst, rhst Type, lhsConst, rhsConst constant.Value)
 		panic("shaderir: cannot resolve untyped values")
 	}
 
+	if op == LeftShift || op == RightShift {
+		if (lhst.Main == Int || lhst.IsIntVector()) && rhst.Main == Int {
+			return lhst, true
+		}
+		if lhst.IsIntVector() && rhst.IsIntVector() && lhst.VectorElementCount() == rhst.VectorElementCount() {
+			return lhst, true
+		}
+		return Type{}, false
+	}
+
 	if op == AndAnd || op == OrOr {
 		if lhst.Main == Bool && rhst.Main == Bool {
 			return Type{Main: Bool}, true

internal/shaderir/program.go

@@ -16,6 +16,7 @@
 package shaderir
 
 import (
+	"go/ast"
 	"go/constant"
 	"go/token"
 	"sort"
@@ -74,16 +75,17 @@ type Block struct {
 }
 
 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
+	Exprs         []Expr
+	Blocks        []*Block
+	ForVarType    Type
+	ForVarIndex   int
+	ForInit       constant.Value
+	ForEnd        constant.Value
+	ForOp         Op
+	ForDelta      constant.Value
+	InitIndex     int
+	IsTypeGuessed bool
 }
 
 type StmtType int
@@ -109,6 +111,7 @@ type Expr struct {
 	Swizzling   string
 	Index       int
 	Op          Op
+	Ast         ast.Expr
 }
 
 type ExprType int