Continued work on GUI (#316)

* Configuration cleanup

* Cleanup

* Continued UI work

d2core/d2asset/font.go

@@ -60,6 +60,10 @@ func loadFont(tablePath, spritePath, palettePath string) (*Font, error) {
 	return font, nil
 }
 
+func (f *Font) SetColor(color color.Color) {
+	f.color = color
+}
+
 func (f *Font) GetTextMetrics(text string) (int, int) {
 	var (
 		lineWidth   int

d2core/d2gui/button.go

@@ -0,0 +1,131 @@
+package d2gui
+
+import (
+	"errors"
+	"image/color"
+
+	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2asset"
+	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2input"
+	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2render"
+)
+
+type buttonState int
+
+const (
+	buttonStateDefault buttonState = iota
+	buttonStatePressed
+	buttonStateToggled
+	buttonStatePressedToggled
+)
+
+type Button struct {
+	widgetBase
+
+	width    int
+	height   int
+	state    buttonState
+	surfaces []d2render.Surface
+}
+
+func createButton(text string, buttonStyle ButtonStyle) (*Button, error) {
+	config, ok := buttonStyleConfigs[buttonStyle]
+	if !ok {
+		return nil, errors.New("invalid button style")
+	}
+
+	animation, err := d2asset.LoadAnimation(config.animationPath, config.palettePath)
+	if err != nil {
+		return nil, err
+	}
+
+	var buttonWidth int
+	for i := 0; i < config.segmentsX; i++ {
+		w, _, err := animation.GetFrameSize(i)
+		if err != nil {
+			return nil, err
+		}
+
+		buttonWidth += w
+	}
+
+	var buttonHeight int
+	for i := 0; i < config.segmentsY; i++ {
+		_, h, err := animation.GetFrameSize(i * config.segmentsY)
+		if err != nil {
+			return nil, err
+		}
+
+		buttonHeight += h
+	}
+
+	font, err := loadFont(config.fontStyle)
+	if err != nil {
+		return nil, err
+	}
+
+	textColor := color.RGBA{R: 0x64, G: 0x64, B: 0x64, A: 0xff}
+	textWidth, textHeight := font.GetTextMetrics(text)
+	textX := buttonWidth/2 - textWidth/2
+	textY := buttonHeight/2 - textHeight/2 + config.textOffset
+
+	surfaceCount := animation.GetFrameCount() / (config.segmentsX * config.segmentsY)
+	surfaces := make([]d2render.Surface, surfaceCount)
+	for i := 0; i < surfaceCount; i++ {
+		surface, err := d2render.NewSurface(buttonWidth, buttonHeight, d2render.FilterNearest)
+		if err != nil {
+			return nil, err
+		}
+
+		if err := renderSegmented(animation, config.segmentsX, config.segmentsY, i, surface); err != nil {
+			return nil, err
+		}
+
+		font.SetColor(textColor)
+
+		var textOffsetX, textOffsetY int
+		switch buttonState(i) {
+		case buttonStatePressed, buttonStatePressedToggled:
+			textOffsetX = -2
+			textOffsetY = 2
+			break
+		}
+
+		surface.PushTranslation(textX+textOffsetX, textY+textOffsetY)
+		err = font.RenderText(text, surface)
+		surface.Pop()
+
+		if err != nil {
+			return nil, err
+		}
+
+		surfaces[i] = surface
+	}
+
+	button := &Button{width: buttonWidth, height: buttonHeight, surfaces: surfaces}
+	button.SetVisible(true)
+
+	return button, nil
+}
+
+func (b *Button) onMouseButtonDown(event d2input.MouseEvent) bool {
+	b.state = buttonStatePressed
+	return false
+}
+
+func (b *Button) onMouseButtonUp(event d2input.MouseEvent) bool {
+	b.state = buttonStateDefault
+	return false
+}
+
+func (b *Button) onMouseLeave(event d2input.MouseMoveEvent) bool {
+	b.state = buttonStateDefault
+	return false
+}
+
+func (b *Button) render(target d2render.Surface) error {
+	return target.Render(b.surfaces[b.state])
+}
+
+func (b *Button) getSize() (int, int) {
+	return b.width, b.height
+}

d2core/d2gui/common.go

@@ -0,0 +1,46 @@
+package d2gui
+
+import (
+	"errors"
+
+	"github.com/OpenDiablo2/OpenDiablo2/d2common"
+	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2asset"
+	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2render"
+)
+
+func loadFont(fontStyle FontStyle) (*d2asset.Font, error) {
+	config, ok := fontStyleConfigs[fontStyle]
+	if !ok {
+		return nil, errors.New("invalid font style")
+	}
+
+	return d2asset.LoadFont(config.fontBasePath+".tbl", config.fontBasePath+".dc6", config.palettePath)
+}
+
+func renderSegmented(animation *d2asset.Animation, segmentsX, segmentsY, frameOffset int, target d2render.Surface) error {
+	var currentY int
+	for y := 0; y < segmentsY; y++ {
+		var currentX int
+		var maxHeight int
+		for x := 0; x < segmentsX; x++ {
+			if err := animation.SetCurrentFrame(x + y*segmentsX + frameOffset*segmentsX*segmentsY); err != nil {
+				return err
+			}
+
+			target.PushTranslation(x+currentX, y+currentY)
+			err := animation.Render(target)
+			target.Pop()
+			if err != nil {
+				return err
+			}
+
+			width, height := animation.GetCurrentFrameSize()
+			maxHeight = d2common.MaxInt(maxHeight, height)
+			currentX += width
+		}
+
+		currentY += maxHeight
+	}
+
+	return nil
+}

d2core/d2gui/d2gui.go

@@ -34,21 +34,14 @@ func Advance(elapsed float64) error {
 	return singleton.advance(elapsed)
 }
 
-func AddLayout() *Layout {
-	return singleton.addLayout()
-}
-
-func AddSprite(imagePath, palettePath string) *Sprite {
-	return singleton.addSprite(imagePath, palettePath)
-}
-
-func AddLabel(text string, fontStyle FontStyle) *Label {
-	return singleton.addLabel(text, fontStyle)
-}
-
-func Clear() {
+func CreateLayout(positionType PositionType) *Layout {
 	verifyWasInit()
-	singleton.clear()
+	return createLayout(positionType)
+}
+
+func SetLayout(layout *Layout) {
+	verifyWasInit()
+	singleton.SetLayout(layout)
 }
 
 func ShowLoadScreen(progress float64) {

d2core/d2gui/label.go

@@ -1,60 +1,41 @@
 package d2gui
 
 import (
-	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2asset"
 	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2render"
 )
 
 type Label struct {
 	widgetBase
 
-	text    string
-	font    *d2asset.Font
 	surface d2render.Surface
 }
 
-func createLabel(text string, fontStyle FontStyle) *Label {
-	font, _ := loadFont(fontStyle)
-	label := &Label{font: font}
-	label.SetText(text)
-	label.visible = true
-	return label
-}
+func createLabel(text string, fontStyle FontStyle) (*Label, error) {
+	font, err := loadFont(fontStyle)
+	if err != nil {
+		return nil, err
+	}
 
-func (l *Label) SetText(text string) *Label {
-	l.text = text
-	l.cache()
-	return l
+	width, height := font.GetTextMetrics(text)
+	surface, err := d2render.NewSurface(width, height, d2render.FilterNearest)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := font.RenderText(text, surface); err != nil {
+		return nil, err
+	}
+
+	label := &Label{surface: surface}
+	label.SetVisible(true)
+
+	return label, nil
 }
 
 func (l *Label) render(target d2render.Surface) error {
-	if l.surface == nil {
-		return nil
-	}
-
 	return target.Render(l.surface)
 }
 
-func (l *Label) cache() error {
-	l.surface = nil
-	if l.font == nil {
-		return nil
-	}
-
-	width, height := l.font.GetTextMetrics(l.text)
-
-	var err error
-	if l.surface, err = d2render.NewSurface(width, height, d2render.FilterNearest); err != nil {
-		return err
-	}
-
-	return l.font.RenderText(l.text, l.surface)
-}
-
 func (l *Label) getSize() (int, int) {
-	if l.surface == nil {
-		return 0, 0
-	}
-
 	return l.surface.GetSize()
 }

d2core/d2gui/layout.go

@@ -3,6 +3,7 @@ package d2gui
 import (
 	"image/color"
 
+	"github.com/OpenDiablo2/OpenDiablo2/d2common"
 	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2input"
 	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2render"
 )
@@ -10,26 +11,136 @@ import (
 type layoutEntry struct {
 	widget widget
 
+	x      int
+	y      int
+	width  int
+	height int
+
 	mouseOver bool
 	mouseDown [3]bool
 }
 
+type VerticalAlign int
+
+const (
+	VerticalAlignTop VerticalAlign = iota
+	VerticalAlignMiddle
+	VerticalAlignBottom
+)
+
+type HorizontalAlign int
+
+const (
+	HorizontalAlignLeft HorizontalAlign = iota
+	HorizontalAlignCenter
+	HorizontalAlignRight
+)
+
+type PositionType int
+
+const (
+	PositionTypeAbsolute PositionType = iota
+	PositionTypeVertical
+	PositionTypeHorizontal
+)
+
 type Layout struct {
 	widgetBase
-	entries []*layoutEntry
+
+	width           int
+	height          int
+	verticalAlign   VerticalAlign
+	horizontalAlign HorizontalAlign
+	positionType    PositionType
+	entries         []*layoutEntry
 }
 
-func createLayout() *Layout {
-	layout := new(Layout)
-	layout.visible = true
+func createLayout(positionType PositionType) *Layout {
+	layout := &Layout{positionType: positionType}
+	layout.SetVisible(true)
+
 	return layout
 }
 
+func (l *Layout) SetSize(width, height int) {
+	l.width = width
+	l.height = height
+}
+
+func (l *Layout) SetVerticalAlign(verticalAlign VerticalAlign) {
+	l.verticalAlign = verticalAlign
+}
+
+func (l *Layout) SetHorizontalAlign(horizontalAlign HorizontalAlign) {
+	l.horizontalAlign = horizontalAlign
+}
+
+func (l *Layout) AddLayout(positionType PositionType) *Layout {
+	layout := createLayout(positionType)
+	l.entries = append(l.entries, &layoutEntry{widget: layout})
+	return layout
+}
+
+func (l *Layout) AddSpacerStatic(width, height int) *SpacerStatic {
+	spacer := createSpacerStatic(width, height)
+	l.entries = append(l.entries, &layoutEntry{widget: spacer})
+	return spacer
+}
+
+func (l *Layout) AddSpacerDynamic() *SpacerDynamic {
+	spacer := createSpacerDynamic()
+	l.entries = append(l.entries, &layoutEntry{widget: spacer})
+	return spacer
+}
+
+func (l *Layout) AddSprite(imagePath, palettePath string) (*Sprite, error) {
+	sprite, err := createSprite(imagePath, palettePath)
+	if err != nil {
+		return nil, err
+	}
+
+	l.entries = append(l.entries, &layoutEntry{widget: sprite})
+	return sprite, nil
+}
+
+func (l *Layout) AddLabel(text string, fontStyle FontStyle) (*Label, error) {
+	label, err := createLabel(text, fontStyle)
+	if err != nil {
+		return nil, err
+	}
+
+	l.entries = append(l.entries, &layoutEntry{widget: label})
+	return label, nil
+}
+
+func (l *Layout) AddButton(text string, buttonStyle ButtonStyle) (*Button, error) {
+	button, err := createButton(text, buttonStyle)
+	if err != nil {
+		return nil, err
+	}
+
+	l.entries = append(l.entries, &layoutEntry{widget: button})
+	return button, nil
+}
+
+func (l *Layout) Clear() {
+	l.entries = nil
+}
+
 func (l *Layout) render(target d2render.Surface) error {
+	l.adjustEntryPlacement()
+
 	for _, entry := range l.entries {
-		if entry.widget.isVisible() {
-			l.renderWidget(entry.widget, target)
-			l.renderWidgetDebug(entry.widget, target)
+		if !entry.widget.isVisible() {
+			continue
+		}
+
+		if err := l.renderEntry(entry, target); err != nil {
+			return err
+		}
+
+		if err := l.renderEntryDebug(entry, target); err != nil {
+			return err
 		}
 	}
 
@@ -38,51 +149,88 @@ func (l *Layout) render(target d2render.Surface) error {
 
 func (l *Layout) advance(elapsed float64) error {
 	for _, entry := range l.entries {
-		if entry.widget.isVisible() {
-			if err := entry.widget.advance(elapsed); err != nil {
-				return err
-			}
+		if err := entry.widget.advance(elapsed); err != nil {
+			return err
 		}
 	}
 
 	return nil
 }
 
-func (l *Layout) renderWidget(widget widget, target d2render.Surface) {
-	target.PushTranslation(widget.getPosition())
+func (l *Layout) renderEntry(entry *layoutEntry, target d2render.Surface) error {
+	target.PushTranslation(entry.x, entry.y)
 	defer target.Pop()
 
-	widget.render(target)
+	return entry.widget.render(target)
 }
 
-func (l *Layout) renderWidgetDebug(widget widget, target d2render.Surface) {
-	target.PushTranslation(widget.getPosition())
+func (l *Layout) renderEntryDebug(entry *layoutEntry, target d2render.Surface) error {
+	target.PushTranslation(entry.x, entry.y)
 	defer target.Pop()
 
-	drawColor := color.RGBA{R: 0x00, G: 0x00, B: 0xff, A: 0xb0}
+	drawColor := color.RGBA{R: 0xff, G: 0xff, B: 0xff, A: 0xff}
+	switch entry.widget.(type) {
+	case *Layout:
+		drawColor = color.RGBA{R: 0xff, G: 0x00, B: 0xff, A: 0xff}
+	case *SpacerStatic, *SpacerDynamic:
+		drawColor = color.RGBA{R: 0x80, G: 0x80, B: 0x80, A: 0xff}
+	case *Label:
+		drawColor = color.RGBA{R: 0x00, G: 0x00, B: 0xff, A: 0xff}
+	case *Button:
+		drawColor = color.RGBA{R: 0xff, G: 0xff, B: 0x00, A: 0xff}
+	}
 
-	width, height := widget.getSize()
-	target.DrawLine(width, 0, drawColor)
-	target.DrawLine(0, height, drawColor)
+	target.DrawLine(entry.width, 0, drawColor)
+	target.DrawLine(0, entry.height, drawColor)
 
-	target.PushTranslation(width, 0)
-	target.DrawLine(0, height, drawColor)
+	target.PushTranslation(entry.width, 0)
+	target.DrawLine(0, entry.height, drawColor)
 	target.Pop()
 
-	target.PushTranslation(0, height)
-	target.DrawLine(width, 0, drawColor)
+	target.PushTranslation(0, entry.height)
+	target.DrawLine(entry.width, 0, drawColor)
 	target.Pop()
+
+	return nil
+}
+
+func (l *Layout) getContentSize() (int, int) {
+	var width, height int
+
+	for _, entry := range l.entries {
+		x, y := entry.widget.getPosition()
+		w, h := entry.widget.getSize()
+
+		switch l.positionType {
+		case PositionTypeVertical:
+			width = d2common.MaxInt(width, w)
+			height += h
+			break
+		case PositionTypeHorizontal:
+			width += w
+			height = d2common.MaxInt(height, h)
+			break
+		case PositionTypeAbsolute:
+			width = d2common.MaxInt(width, x+w)
+			height = d2common.MaxInt(height, y+h)
+			break
+		}
+	}
+
+	return width, height
 }
 
 func (l *Layout) getSize() (int, int) {
-	return 0, 0
+	width, height := l.getContentSize()
+	return d2common.MaxInt(width, l.width), d2common.MaxInt(height, l.height)
 }
 
 func (l *Layout) onMouseButtonDown(event d2input.MouseEvent) bool {
 	for _, entry := range l.entries {
 		eventLocal := event
 
-		if l.adjustEventCoords(entry.widget, &eventLocal.X, &eventLocal.Y) {
+		if l.adjustEntryEvent(entry, &eventLocal.X, &eventLocal.Y) {
+			entry.widget.onMouseButtonDown(eventLocal)
 			entry.mouseDown[event.Button] = true
 		}
 	}
@@ -94,9 +242,10 @@ func (l *Layout) onMouseButtonUp(event d2input.MouseEvent) bool {
 	for _, entry := range l.entries {
 		eventLocal := event
 
-		if l.adjustEventCoords(entry.widget, &eventLocal.X, &eventLocal.Y) {
+		if l.adjustEntryEvent(entry, &eventLocal.X, &eventLocal.Y) {
 			if entry.mouseDown[event.Button] {
-				entry.widget.onMouseClick(eventLocal)
+				entry.widget.onMouseButtonClick(eventLocal)
+				entry.widget.onMouseButtonUp(eventLocal)
 			}
 		}
 
@@ -110,7 +259,8 @@ func (l *Layout) onMouseMove(event d2input.MouseMoveEvent) bool {
 	for _, entry := range l.entries {
 		eventLocal := event
 
-		if l.adjustEventCoords(entry.widget, &eventLocal.X, &eventLocal.Y) {
+		if l.adjustEntryEvent(entry, &eventLocal.X, &eventLocal.Y) {
+			entry.widget.onMouseMove(eventLocal)
 			if entry.mouseOver {
 				entry.widget.onMouseOver(eventLocal)
 			} else {
@@ -126,38 +276,90 @@ func (l *Layout) onMouseMove(event d2input.MouseMoveEvent) bool {
 	return false
 }
 
-func (l *Layout) adjustEventCoords(widget widget, eventX, eventY *int) bool {
-	x, y := widget.getPosition()
-	width, height := widget.getSize()
+func (l *Layout) adjustEntryEvent(entry *layoutEntry, eventX, eventY *int) bool {
+	*eventX -= entry.x
+	*eventY -= entry.y
 
-	*eventX -= x
-	*eventY -= y
-
-	if *eventX < 0 || *eventY < 0 || *eventX >= width || *eventY >= height {
+	if *eventX < 0 || *eventY < 0 || *eventX >= entry.width || *eventY >= entry.height {
 		return false
 	}
 
 	return true
 }
 
-func (l *Layout) addLayout() *Layout {
-	layout := createLayout()
-	l.entries = append(l.entries, &layoutEntry{widget: layout})
-	return layout
-}
+func (l *Layout) adjustEntryPlacement() {
+	width, height := l.getSize()
 
-func (l *Layout) addSprite(imagePath, palettePath string) *Sprite {
-	sprite := createSprite(imagePath, palettePath)
-	l.entries = append(l.entries, &layoutEntry{widget: sprite})
-	return sprite
-}
+	var expanderCount int
+	for _, entry := range l.entries {
+		if entry.widget.isVisible() && entry.widget.isExpanding() {
+			expanderCount++
+		}
+	}
 
-func (l *Layout) addLabel(text string, fontStyle FontStyle) *Label {
-	label := createLabel(text, fontStyle)
-	l.entries = append(l.entries, &layoutEntry{widget: label})
-	return label
-}
+	var expanderWidth, expanderHeight int
+	if expanderCount > 0 {
+		contentWidth, contentHeight := l.getContentSize()
 
-func (l *Layout) clear() {
-	l.entries = nil
+		switch l.positionType {
+		case PositionTypeVertical:
+			expanderHeight = (height - contentHeight) / expanderCount
+			break
+		case PositionTypeHorizontal:
+			expanderWidth = (width - contentWidth) / expanderCount
+			break
+		}
+
+		expanderWidth = d2common.MaxInt(0, expanderWidth)
+		expanderHeight = d2common.MaxInt(0, expanderHeight)
+	}
+
+	var offsetX, offsetY int
+	for _, entry := range l.entries {
+		if !entry.widget.isVisible() {
+			continue
+		}
+
+		if entry.widget.isExpanding() {
+			entry.width, entry.height = expanderWidth, expanderHeight
+		} else {
+			entry.width, entry.height = entry.widget.getSize()
+		}
+
+		switch l.positionType {
+		case PositionTypeVertical:
+			entry.y = offsetY
+			offsetY += entry.height
+			switch l.horizontalAlign {
+			case HorizontalAlignLeft:
+				entry.x = 0
+				break
+			case HorizontalAlignCenter:
+				entry.x = width/2 - entry.width/2
+				break
+			case HorizontalAlignRight:
+				entry.x = width - entry.width
+				break
+			}
+			break
+		case PositionTypeHorizontal:
+			entry.x = offsetX
+			offsetX += entry.width
+			switch l.verticalAlign {
+			case VerticalAlignTop:
+				entry.y = 0
+				break
+			case VerticalAlignMiddle:
+				entry.y = height/2 - entry.height/2
+				break
+			case VerticalAlignBottom:
+				entry.y = height - entry.height
+				break
+			}
+			break
+		case PositionTypeAbsolute:
+			entry.x, entry.y = entry.widget.getPosition()
+			break
+		}
+	}
 }

d2core/d2gui/manager.go

@@ -11,7 +11,7 @@ import (
 )
 
 type manager struct {
-	Layout
+	layout *Layout
 
 	cursorAnim    *d2asset.Animation
 	cursorX       int
@@ -46,19 +46,35 @@ func createGuiManager() (*manager, error) {
 	return manager, nil
 }
 
+func (m *manager) SetLayout(layout *Layout) {
+	m.layout = layout
+}
+
 func (m *manager) OnMouseButtonDown(event d2input.MouseEvent) bool {
-	return m.Layout.onMouseButtonDown(event)
+	if m.layout == nil {
+		return false
+	}
+
+	return m.layout.onMouseButtonDown(event)
 }
 
 func (m *manager) OnMouseButtonUp(event d2input.MouseEvent) bool {
-	return m.Layout.onMouseButtonUp(event)
+	if m.layout == nil {
+		return false
+	}
+
+	return m.layout.onMouseButtonUp(event)
 }
 
 func (m *manager) OnMouseMove(event d2input.MouseMoveEvent) bool {
 	m.cursorX = event.X
 	m.cursorY = event.Y
 
-	return m.Layout.onMouseMove(event)
+	if m.layout == nil {
+		return false
+	}
+
+	return m.layout.onMouseMove(event)
 }
 
 func (m *manager) render(target d2render.Surface) error {
@@ -66,8 +82,9 @@ func (m *manager) render(target d2render.Surface) error {
 		if err := m.renderLoadScreen(target); err != nil {
 			return err
 		}
-	} else {
-		if err := m.Layout.render(target); err != nil {
+	} else if m.layout != nil {
+		m.layout.SetSize(target.GetSize())
+		if err := m.layout.render(target); err != nil {
 			return err
 		}
 	}
@@ -103,8 +120,8 @@ func (m *manager) renderCursor(target d2render.Surface) error {
 }
 
 func (m *manager) advance(elapsed float64) error {
-	if !m.loading {
-		if err := m.Layout.advance(elapsed); err != nil {
+	if !m.loading && m.layout != nil {
+		if err := m.layout.advance(elapsed); err != nil {
 			return err
 		}
 	}
@@ -136,6 +153,6 @@ func (m *manager) hideCursor() {
 }
 
 func (m *manager) clear() {
-	m.Layout.clear()
+	m.SetLayout(nil)
 	m.hideLoadScreen()
 }

d2core/d2gui/spacer.go

@@ -0,0 +1,31 @@
+package d2gui
+
+type SpacerStatic struct {
+	widgetBase
+
+	width  int
+	height int
+}
+
+func createSpacerStatic(width, height int) *SpacerStatic {
+	spacer := &SpacerStatic{width: width, height: height}
+	spacer.SetVisible(true)
+
+	return spacer
+}
+
+func (s *SpacerStatic) getSize() (int, int) {
+	return s.width, s.height
+}
+
+type SpacerDynamic struct {
+	widgetBase
+}
+
+func createSpacerDynamic() *SpacerDynamic {
+	spacer := &SpacerDynamic{}
+	spacer.SetVisible(true)
+	spacer.SetExpanding(true)
+
+	return spacer
+}

d2core/d2gui/sprite.go

@@ -1,7 +1,6 @@
 package d2gui
 
 import (
-	"github.com/OpenDiablo2/OpenDiablo2/d2common"
 	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2asset"
 	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2render"
 )
@@ -16,11 +15,17 @@ type Sprite struct {
 	animation *d2asset.Animation
 }
 
-func createSprite(imagePath, palettePath string) *Sprite {
-	sprite := new(Sprite)
-	sprite.animation, _ = d2asset.LoadAnimation(imagePath, palettePath)
-	sprite.visible = true
-	return sprite
+func createSprite(imagePath, palettePath string) (*Sprite, error) {
+	animation, err := d2asset.LoadAnimation(imagePath, palettePath)
+	if err != nil {
+		return nil, err
+	}
+
+	sprite := &Sprite{}
+	sprite.animation = animation
+	sprite.SetVisible(true)
+
+	return sprite, nil
 }
 
 func (s *Sprite) SetSegmented(segmentsX, segmentsY, frameOffset int) {
@@ -30,57 +35,13 @@ func (s *Sprite) SetSegmented(segmentsX, segmentsY, frameOffset int) {
 }
 
 func (s *Sprite) render(target d2render.Surface) error {
-	if s.animation == nil {
-		return nil
-	}
-
-	_, height := s.animation.GetCurrentFrameSize()
-	target.PushTranslation(0, -height)
-	defer target.Pop()
-
-	if s.segmentsX == 0 && s.segmentsY == 0 {
-		return s.animation.Render(target)
-	}
-
-	var currentY int
-	for y := 0; y < s.segmentsY; y++ {
-		var currentX int
-		var maxHeight int
-		for x := 0; x < s.segmentsX; x++ {
-			if err := s.animation.SetCurrentFrame(x + y*s.segmentsX + s.frameOffset*s.segmentsX*s.segmentsY); err != nil {
-				return err
-			}
-
-			target.PushTranslation(s.x+currentX, s.y+currentY)
-			err := s.animation.Render(target)
-			target.Pop()
-			if err != nil {
-				return err
-			}
-
-			width, height := s.animation.GetCurrentFrameSize()
-			maxHeight = d2common.MaxInt(maxHeight, height)
-			currentX += width
-		}
-
-		currentY += maxHeight
-	}
-
-	return nil
+	return renderSegmented(s.animation, s.segmentsX, s.segmentsY, s.frameOffset, target)
 }
 
 func (s *Sprite) advance(elapsed float64) error {
-	if s.animation == nil {
-		return nil
-	}
-
 	return s.animation.Advance(elapsed)
 }
 
 func (s *Sprite) getSize() (int, int) {
-	if s.animation == nil {
-		return 0, 0
-	}
-
 	return s.animation.GetCurrentFrameSize()
 }

d2core/d2gui/style.go

@@ -2,7 +2,6 @@ package d2gui
 
 import (
 	"github.com/OpenDiablo2/OpenDiablo2/d2common/d2resource"
-	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2asset"
 )
 
 type FontStyle int
@@ -11,9 +10,11 @@ const (
 	FontStyle16Units FontStyle = iota
 	FontStyle30Units
 	FontStyle42Units
+	FontStyleExocet10
 	FontStyleFormal10Static
 	FontStyleFormal11Units
 	FontStyleFormal12Static
+	FontStyleRediculous
 )
 
 type fontStyleConfig struct {
@@ -25,12 +26,37 @@ var fontStyleConfigs = map[FontStyle]fontStyleConfig{
 	FontStyle16Units:        {d2resource.Font16, d2resource.PaletteUnits},
 	FontStyle30Units:        {d2resource.Font30, d2resource.PaletteUnits},
 	FontStyle42Units:        {d2resource.Font42, d2resource.PaletteUnits},
+	FontStyleExocet10:       {d2resource.FontExocet10, d2resource.PaletteUnits},
 	FontStyleFormal10Static: {d2resource.FontFormal10, d2resource.PaletteStatic},
 	FontStyleFormal11Units:  {d2resource.FontFormal11, d2resource.PaletteUnits},
 	FontStyleFormal12Static: {d2resource.FontFormal12, d2resource.PaletteStatic},
+	FontStyleRediculous:     {d2resource.FontRediculous, d2resource.PaletteUnits},
 }
 
-func loadFont(fontStyle FontStyle) (*d2asset.Font, error) {
-	config := fontStyleConfigs[fontStyle]
-	return d2asset.LoadFont(config.fontBasePath+".tbl", config.fontBasePath+".dc6", config.palettePath)
+type ButtonStyle int
+
+type buttonStyleConfig struct {
+	segmentsX     int
+	segmentsY     int
+	animationPath string
+	palettePath   string
+	fontStyle     FontStyle
+	textOffset    int
+}
+
+const (
+	ButtonStyleMedium ButtonStyle = iota
+	ButtonStyleNarrow
+	ButtonStyleOkCancel
+	ButtonStyleShort
+	ButtonStyleTall
+	ButtonStyleWide
+)
+
+var buttonStyleConfigs = map[ButtonStyle]buttonStyleConfig{
+	ButtonStyleMedium:   {1, 1, d2resource.MediumButtonBlank, d2resource.PaletteUnits, FontStyleExocet10, 0},
+	ButtonStyleOkCancel: {1, 1, d2resource.CancelButton, d2resource.PaletteUnits, FontStyleRediculous, 0},
+	ButtonStyleShort:    {1, 1, d2resource.ShortButtonBlank, d2resource.PaletteUnits, FontStyleRediculous, -1},
+	ButtonStyleTall:     {1, 1, d2resource.TallButtonBlank, d2resource.PaletteUnits, FontStyleExocet10, 5},
+	ButtonStyleWide:     {2, 1, d2resource.WideButtonBlank, d2resource.PaletteUnits, FontStyleExocet10, 1},
 }

d2core/d2gui/widget.go

@@ -12,26 +12,30 @@ type widget interface {
 	render(target d2render.Surface) error
 	advance(elapsed float64) error
 
-	onMouseEnter(event d2input.MouseMoveEvent)
-	onMouseLeave(event d2input.MouseMoveEvent)
-	onMouseOver(event d2input.MouseMoveEvent)
-	onMouseClick(event d2input.MouseEvent)
+	onMouseMove(event d2input.MouseMoveEvent) bool
+	onMouseEnter(event d2input.MouseMoveEvent) bool
+	onMouseLeave(event d2input.MouseMoveEvent) bool
+	onMouseOver(event d2input.MouseMoveEvent) bool
+	onMouseButtonDown(event d2input.MouseEvent) bool
+	onMouseButtonUp(event d2input.MouseEvent) bool
+	onMouseButtonClick(event d2input.MouseEvent) bool
 
 	getPosition() (int, int)
 	getSize() (int, int)
 	getLayer() int
 	isVisible() bool
+	isExpanding() bool
 }
 
 type widgetBase struct {
-	x       int
-	y       int
-	layer   int
-	visible bool
+	x         int
+	y         int
+	layer     int
+	visible   bool
+	expanding bool
 
 	mouseEnterHandler MouseMoveHandler
 	mouseLeaveHandler MouseMoveHandler
-	mouseMoveHandler  MouseMoveHandler
 	mouseClickHandler MouseHandler
 }
 
@@ -48,6 +52,10 @@ func (w *widgetBase) SetVisible(visible bool) {
 	w.visible = visible
 }
 
+func (w *widgetBase) SetExpanding(expanding bool) {
+	w.expanding = expanding
+}
+
 func (w *widgetBase) SetMouseEnterHandler(handler MouseMoveHandler) {
 	w.mouseEnterHandler = handler
 }
@@ -56,10 +64,6 @@ func (w *widgetBase) SetMouseLeaveHandler(handler MouseMoveHandler) {
 	w.mouseLeaveHandler = handler
 }
 
-func (w *widgetBase) SetMouseMoveHandler(handler MouseMoveHandler) {
-	w.mouseMoveHandler = handler
-}
-
 func (w *widgetBase) SetMouseClickHandler(handler MouseHandler) {
 	w.mouseClickHandler = handler
 }
@@ -68,6 +72,10 @@ func (w *widgetBase) getPosition() (int, int) {
 	return w.x, w.y
 }
 
+func (w *widgetBase) getSize() (int, int) {
+	return 0, 0
+}
+
 func (w *widgetBase) getLayer() int {
 	return w.layer
 }
@@ -76,30 +84,54 @@ func (w *widgetBase) isVisible() bool {
 	return w.visible
 }
 
+func (w *widgetBase) isExpanding() bool {
+	return w.expanding
+}
+
+func (w *widgetBase) render(target d2render.Surface) error {
+	return nil
+}
+
 func (w *widgetBase) advance(elapsed float64) error {
 	return nil
 }
 
-func (w *widgetBase) onMouseEnter(event d2input.MouseMoveEvent) {
+func (w *widgetBase) onMouseEnter(event d2input.MouseMoveEvent) bool {
 	if w.mouseEnterHandler != nil {
 		w.mouseEnterHandler(event)
 	}
+
+	return false
 }
 
-func (w *widgetBase) onMouseLeave(event d2input.MouseMoveEvent) {
+func (w *widgetBase) onMouseLeave(event d2input.MouseMoveEvent) bool {
 	if w.mouseLeaveHandler != nil {
 		w.mouseLeaveHandler(event)
 	}
+
+	return false
 }
 
-func (w *widgetBase) onMouseOver(event d2input.MouseMoveEvent) {
-	if w.mouseMoveHandler != nil {
-		w.mouseMoveHandler(event)
-	}
-}
-
-func (w *widgetBase) onMouseClick(event d2input.MouseEvent) {
+func (w *widgetBase) onMouseButtonClick(event d2input.MouseEvent) bool {
 	if w.mouseClickHandler != nil {
 		w.mouseClickHandler(event)
 	}
+
+	return false
+}
+
+func (w *widgetBase) onMouseMove(event d2input.MouseMoveEvent) bool {
+	return false
+}
+
+func (w *widgetBase) onMouseOver(event d2input.MouseMoveEvent) bool {
+	return false
+}
+
+func (w *widgetBase) onMouseButtonDown(event d2input.MouseEvent) bool {
+	return false
+}
+
+func (w *widgetBase) onMouseButtonUp(event d2input.MouseEvent) bool {
+	return false
 }

d2core/d2scene/d2scene.go

@@ -43,7 +43,7 @@ func Advance(elapsed float64) error {
 		}
 
 		d2ui.Reset()
-		d2gui.Clear()
+		d2gui.SetLayout(nil)
 
 		if _, ok := singleton.nextScene.(SceneLoadHandler); ok {
 			d2gui.ShowLoadScreen(0)

d2game/d2gamescene/gui_testing.go

@@ -0,0 +1,49 @@
+package d2gamescene
+
+import (
+	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2gui"
+	"github.com/OpenDiablo2/OpenDiablo2/d2core/d2render"
+)
+
+type GuiTestMain struct{}
+
+func CreateGuiTestMain() *GuiTestMain {
+	return &GuiTestMain{}
+}
+
+func (g *GuiTestMain) OnLoad() error {
+	layout := d2gui.CreateLayout(d2gui.PositionTypeHorizontal)
+	//
+	layoutLeft := layout.AddLayout(d2gui.PositionTypeVertical)
+	layoutLeft.SetHorizontalAlign(d2gui.HorizontalAlignCenter)
+	layoutLeft.AddLabel("FontStyle16Units", d2gui.FontStyle16Units)
+	layoutLeft.AddSpacerStatic(0, 100)
+	layoutLeft.AddLabel("FontStyle30Units", d2gui.FontStyle30Units)
+	layoutLeft.AddLabel("FontStyle42Units", d2gui.FontStyle42Units)
+	layoutLeft.AddLabel("FontStyleFormal10Static", d2gui.FontStyleFormal10Static)
+	layoutLeft.AddLabel("FontStyleFormal11Units", d2gui.FontStyleFormal11Units)
+	layoutLeft.AddLabel("FontStyleFormal12Static", d2gui.FontStyleFormal12Static)
+
+	layout.AddSpacerDynamic()
+
+	layoutRight := layout.AddLayout(d2gui.PositionTypeVertical)
+	layoutRight.SetHorizontalAlign(d2gui.HorizontalAlignRight)
+	layoutRight.AddButton("Medium", d2gui.ButtonStyleMedium)
+	layoutRight.AddButton("Narrow", d2gui.ButtonStyleNarrow)
+	layoutRight.AddButton("OkCancel", d2gui.ButtonStyleOkCancel)
+	layoutRight.AddButton("Short", d2gui.ButtonStyleShort)
+	layoutRight.AddButton("Wide", d2gui.ButtonStyleWide)
+
+	layout.SetVerticalAlign(d2gui.VerticalAlignMiddle)
+	d2gui.SetLayout(layout)
+
+	return nil
+}
+
+func (g *GuiTestMain) Render(screen d2render.Surface) error {
+	return nil
+}
+
+func (g *GuiTestMain) Advance(tickTime float64) error {
+	return nil
+}

main.go

@@ -153,6 +153,9 @@ func initialize() error {
 	d2term.BindAction("quit", "exits the game", func() {
 		os.Exit(0)
 	})
+	d2term.BindAction("scene-gui", "enters the gui playground scene", func() {
+		d2scene.SetNextScene(d2gamescene.CreateGuiTestMain())
+	})
 
 	if err := d2asset.Initialize(); err != nil {
 		return err