yaze/docs/internal/agents/archive/draw-routines-2025-12-07/draw_routine_fixes_phase2.md

Draw Routine Fixes - Phase 2

Status

Owner: ai-dungeon-specialist
Created: 2025-12-07
Status: Partial Complete - Build Verified

Summary

This document tracks fixes for specific dungeon object draw routines and outline sizing issues identified during testing. These issues complement the Phase 1 diagonal/edge/spacing fixes.

Issues to Fix

Issue 1: Block 0x5E Draw Routine Inverted

Object: 0x5E (RoomDraw_RightwardsBlock2x2spaced2_1to16)
Problem: Draw routine is inverted for the simple block pattern
ASM Reference: bank_01.asm line 363
Fix Required: Review tile ordering and column-major vs row-major layout

Issue 2: Vertical Pegs Wrong Outline Shape

Objects: 0x95 (DownwardsPots2x2), 0x96 (DownwardsHammerPegs2x2)
Problem: Selection outline shows 2x2 square but should be vertical single row (1 tile wide)
ASM Reference: RoomDraw_DownwardsPots2x2_1to16, RoomDraw_DownwardsHammerPegs2x2_1to16
Analysis: The pots/pegs are 2x2 objects that repeat vertically with 2-row spacing (0x100). However, user reports they should display as 1-tile-wide vertical strips. Need to verify actual drawn dimensions from ASM.
Fix Required: Update dimension calculations in CalculateObjectDimensions and ObjectDimensionTable

Issue 3: Thick Rail Horizontal/Vertical Draw Issues

Objects: 0x5D (RightwardsBigRail1x3), 0x88 (DownwardsBigRail3x1)
Problem: Repeats far left edge rather than inner parts of the thick rail
ASM Reference: RoomDraw_RightwardsBigRail1x3_1to16plus5, RoomDraw_DownwardsBigRail3x1_1to16plus5
Analysis: ASM shows:

• First draws a 2x2 block, then advances tile pointer by 8
• Then draws middle section (1x3 tiles per iteration)
• Finally draws end cap (2 tiles) Fix Required: Fix draw routine to draw: left cap → middle repeating → right cap

Issue 4: Large Decor Outline Too Small, Draw Routine Repeats Incorrectly

Problem: Large decoration objects have outlines that are too small and draw routines that repeat when they shouldn't
Fix Required: Identify specific objects and verify repetition count logic (size+1 vs size)

Issue 5: Ceiling 0xC0 Doesn't Draw Properly

Object: 0xC0 (RoomDraw_4x4BlocksIn4x4SuperSquare)
Problem: Object doesn't draw at all or draws incorrectly
ASM Reference: bank_01.asm lines 1779-1831
Analysis: Uses complex 4x4 super-square pattern with 8 buffer pointers ($BF through $D4). Draws 4x4 blocks in a grid pattern based on size parameters B2 and B4.
Fix Required: Implement proper super-square drawing routine

Issue 6: 0xF99 Chest Outline Correct But Draw Routine Repeats

Object: 0xF99 (RoomDraw_Chest - Type 3 chest)
Problem: Outline is correct but draw routine repeats when it shouldn't
ASM Reference: RoomDraw_Chest at bank_01.asm line 4707
Analysis: Chest should only draw once (single 2x2 pattern), not repeat based on size
Fix Required: Remove size-based repetition from chest draw routine

Issue 7: Pit Edges Outlines Too Thin

Problem: Pit edge outlines shouldn't be single tile thin based on direction
Objects: Various pit edge objects
Fix Required: Update pit edge dimension calculations to include proper width based on direction

Issue 8: 0x3D Tall Torches Wrong Top Half Graphics

Object: 0x3D (mapped to RoomDraw_RightwardsPillar2x4spaced4_1to16)
Problem: Bottom half draws correctly but top half with fire draws pegs instead
ASM Reference: bank_01.asm line 330 - uses RoomDraw_RightwardsPillar2x4spaced4_1to16 (same as 0x39)
Analysis: Object 0x3D and 0x39 share the same draw routine but use different tile data. Need to verify tile data offset is correct.
Fix Required: Verify tile data loading for 0x3D or create dedicated draw routine

Implementation Status

Completed Fixes

1. Block 0x5E ✅ - Fixed tile ordering in DrawRightwardsBlock2x2spaced2_1to16 to use column-major order
2. Thick Rails 0x5D/0x88 ✅ - Rewrote DrawRightwardsBigRail and DrawDownwardsBigRail to correctly draw cap-middle-cap pattern
3. Chest 0xF99 ✅ - Fixed chest to draw single 2x2 pattern without size-based repetition
4. Large Decor 0xFEB ✅ - Created Single4x4 routine (routine 113) - no repetition, correct 32x32 outline
5. Water Grate 0xFED ✅ - Created Single4x3 routine (routine 114) - no repetition, correct 32x24 outline
6. Big Chest 0xFB1 ✅ - Mapped to Single4x3 routine (routine 114) - no repetition
7. Blue Rupees 0xF92 ✅ - Created DrawRupeeFloor routine (routine 115) - special 6x8 pattern with gaps

Pending Investigation

8. Rails 0x022 - Uses RoomDraw_RightwardsHasEdge1x1_1to16_plus3 - needs internal rail drawing
9. Ceiling 0xC0 - Draw4x4BlocksIn4x4SuperSquare may have tile loading issue
10. Vertical Pegs 0x95/0x96 - Current dimensions look correct. May be UI display issue.
11. Pit Edges - Need specific object IDs to investigate
12. Torches 0x3D - May be ROM tile data issue (verify data at 0x807A)

New Routines Added

• Routine 113: DrawSingle4x4 - Single 4x4 block, no repetition
• Routine 114: DrawSingle4x3 - Single 4x3 block, no repetition
• Routine 115: DrawRupeeFloor - Special 6x8 pattern with gaps at rows 2 and 5

Files Modified

• src/zelda3/dungeon/object_drawer.cc
• src/zelda3/dungeon/object_drawer.h
• docs/internal/agents/draw_routine_fixes_phase2.md