DungeonHotbar Conversion: Minecraft 1.21+ → 1.20.1 Fabric

Core API Changes

1.21+	1.20.1
Identifier.of("mod", "path")	new Identifier("mod", "path")
RenderPipelines.GUI_TEXTURED	RenderSystem.setShader(GameRenderer::getPositionTexProgram)
HudElementRegistry.replaceElement()	HudRenderCallback.EVENT + mixins
drawStackOverlay()	drawItemInSlot()
getSelectedSlot()	selectedSlot (field)
EntityAttributes.JUMP_STRENGTH	EntityAttributes.HORSE_JUMP_STRENGTH

MatrixStack Methods

1.21+	1.20.1
pushMatrix()	push()
popMatrix()	pop()
translate(x, y)	translate(x, y, 0)
scale(x, y)	scale(x, y, 1.0f)

drawTexture() Signature

1.21+	1.20.1
11 params (with RenderPipeline + UV region)	8 params: drawTexture(tex, x, y, u, v, w, h, texW, texH)
UV cropping from spritesheet	Full texture via scale()

Textures

1.21+	1.20.1
Spritesheets (widgets.png, icons.png)	Separate files (dungeon_hotbar.png, icon_water.png, ...)
UV: u1,v1,u2,v2	UV: 0,0 — whole texture

HUD Registration

1.21+	1.20.1
HudElementRegistry.replaceElement(VanillaHudElements.HOTBAR, ...)	HudRenderCallback.EVENT.register(...)
Hide vanilla elements via replacement	Hide via @Inject(..., cancellable = true) + ci.cancel()

Progress Bars

Parameter	Before (1.21+)	After (1.20.1)
Water icon	Index 0 (air)	Index 3 (icon_water)
Jump icon	None	Index 4 (icon_health_mount)
Level text	Above bar	Left side, same line
Jump text	Above bar	Left side, same line
Water bar visibility	Always	Only underwater (player.getAir() < player.getMaxAir())
Bar height	2px (Scale1) / 1px	2px (Scale1) / 1px

Stat Icons (HP, Armor, Food, Mount)

Parameter	Before	After
Position	Next to text	Above text, centered
Size	Fixed	Configurable (ICON_SIZE, ICON_OFFSET_Y)

Mixins (InGameHudMixin)

Cancel vanilla rendering for:

• renderHotbar(float, DrawContext, CallbackInfo) — hotbar
• renderStatusBars(DrawContext, CallbackInfo) — health bars
• renderExperienceBar(DrawContext, int, CallbackInfo) — experience
• renderStatusEffectOverlay(DrawContext, CallbackInfo) — effects
• renderMountHealth(DrawContext, CallbackInfo) — mount health
• renderHeldItemTooltip(DrawContext, CallbackInfo) — item name

File Structure (20 classes)