DavidSM64 · Ryan-Myers · Dec 4, 2025 · Dec 4, 2025 · Dec 4, 2025 · Dec 8, 2025
diff --git a/Makefile b/Makefile
@@ -59,7 +59,7 @@ BUILD_DIR = build
 SRC_DIR   = src
 LIBULTRA_DIR = libultra
 ASM_DIRS  = asm asm/data asm/assets asm/nonmatchings
-HASM_DIRS = $(SRC_DIR)/hasm $(LIBULTRA_DIR)/src/os $(LIBULTRA_DIR)/src/gu $(LIBULTRA_DIR)/src/libc
+HASM_DIRS = $(SRC_DIR)/hasm $(SRC_DIR)/hasm/ido $(LIBULTRA_DIR)/src/os $(LIBULTRA_DIR)/src/gu $(LIBULTRA_DIR)/src/libc
 LIBULTRA_SRC_DIRS  = $(LIBULTRA_DIR) $(LIBULTRA_DIR)/src $(LIBULTRA_DIR)/src/audio $(LIBULTRA_DIR)/src/audio/mips1
 LIBULTRA_SRC_DIRS += $(LIBULTRA_DIR)/src/debug $(LIBULTRA_DIR)/src/gu $(LIBULTRA_DIR)/src/io
 LIBULTRA_SRC_DIRS += $(LIBULTRA_DIR)/src/libc $(LIBULTRA_DIR)/src/os $(LIBULTRA_DIR)/src/sc
@@ -188,6 +188,7 @@ C_DEFINES += -DCIC_ID=$(BOOT_CIC)
 INCLUDE_CFLAGS  = -I . -I include -I include/libc  -I include/PR -I include/sys -I $(BIN_DIRS) -I $(SRC_DIR) -I $(LIBULTRA_DIR)
 INCLUDE_CFLAGS += -I $(LIBULTRA_DIR)/src/gu -I $(LIBULTRA_DIR)/src/libc -I $(LIBULTRA_DIR)/src/io  -I $(LIBULTRA_DIR)/src/sc
 INCLUDE_CFLAGS += -I $(LIBULTRA_DIR)/src/audio -I $(LIBULTRA_DIR)/src/os
+INCLUDE_CFLAGS += -I $(SRC_DIR)/hasm -I $(SRC_DIR)/hasm/ido
 
 ASFLAGS        = -march=vr4300 -32 -G0 $(ASM_DEFINES) $(INCLUDE_CFLAGS)
 OBJCOPYFLAGS   = -O binary
@@ -275,6 +276,9 @@ $(BUILD_DIR)/$(LIBULTRA_DIR)/%.s.o: MIPSISET := -mips2
 $(BUILD_DIR)/$(LIBULTRA_DIR)/src/libc/%.s.o: OPT_FLAGS := -O2
 $(BUILD_DIR)/$(LIBULTRA_DIR)/src/os/exceptasm.s.o: MIPSISET := -mips3 -32
 
+$(BUILD_DIR)/$(SRC_DIR)/hasm/ido/math_util.s.o: OPT_FLAGS := -O2
+$(BUILD_DIR)/$(SRC_DIR)/hasm/ido/math_util.s.o: MIPSISET := -mips3 -32
+
 # Allow dollar sign to be used in var names for this file alone
 # It allows us to return the current stack pointer
 $(BUILD_DIR)/$(SRC_DIR)/get_stack_pointer.c.o: OPT_FLAGS += -dollar
@@ -464,6 +468,13 @@ $(BUILD_DIR)/$(LIBULTRA_DIR)/%.s.o: $(LIBULTRA_DIR)/%.s | build_assets
 	@if [ "$(MIPSISET)" = "-mips3 -32" ]; then \
 		$(PYTHON) $(TOOLS_DIR)/python/patchmips3.py $@ || rm $@; \
 	fi
+$(BUILD_DIR)/$(SRC_DIR)/hasm/ido/%.s.o: $(SRC_DIR)/hasm/ido/%.s | build_assets
+	$(call print,Assembling IDO:,$<,$@)
+	$(V)$(CC) -c $(CFLAGS) $(CC_WARNINGS) $(OPT_FLAGS) $(MIPSISET) -o $@ $<
+	$(V)$(STRIP) --strip-unneeded $@
+	@if [ "$(MIPSISET)" = "-mips3 -32" ]; then \
+		$(PYTHON) $(TOOLS_DIR)/python/patchmips3.py $@ || rm $@; \
+	fi
 else
 # libultra asm files - Compile with the gcc c compiler
 $(BUILD_DIR)/$(LIBULTRA_DIR)/%.s.o: $(LIBULTRA_DIR)/%.s | build_assets

diff --git a/src/hasm/ido/asm_macros.h b/src/hasm/ido/asm_macros.h
@@ -0,0 +1,17 @@
+/* 
+    Define a macro for signed multiplication of two registers, storing the result in a destination register
+    This is similar to the MUL instruction but is mult instead of multu.
+*/
+#define MULS(rd, rs, rt) \
+    mult   rs, rt; \
+    mflo   rd \
+
+/* 
+    I think they accidentally used mul instead of mult.
+    This causes issues if they rd and rs are different registers as
+    rs would get overwritten by the mult instruction.
+    It also wastes and extra instruction with the extra mflo at the end.
+*/
+#define MUL(rd, rs, rt) \
+    mul    rs, rt; \
+    mflo   rd /* (mul pseudo-op already does this, but original has it) */ \
diff --git a/src/hasm/ido/math_util.s b/src/hasm/ido/math_util.s
diff --git a/src/hasm/math_util.c b/src/hasm/math_util.c
@@ -645,8 +645,8 @@ void vec3f_rotate_py(Vec3s *rotation, Vec3f *vec) {
 
     z = vec->z;
 
-    vec->x = z * cosX * sinY;
-    vec->y = -z * sinX;
+    vec->x = z * cosY * sinX;
+    vec->y = -z * sinY;
     vec->z = z * cosX * cosY;
 }
 #else
@@ -747,6 +747,10 @@ static u16 atan2_lookup(f32 y, f32 x) {
 s32 atan2s(s32 xDelta, s32 zDelta) {
     u16 ret;
 
+    if (xDelta == 0 && yDelta == 0) {
+        return 0;
+    }
+
     if (xDelta >= 0) {
         if (zDelta >= 0) {
             if (zDelta >= xDelta) {
@@ -897,7 +901,7 @@ GLOBAL_ASM("asm/math_util/area_triangle_2d.s")
 GLOBAL_ASM("asm/math_util/set_breakpoint.s")
 
 #ifdef NON_MATCHING
-void dmacopy_doubleword(void *src, void *dst, s32 end) {
+void dmacopy_doubleword(void *src, void *dst, u32 end) {
     s32 size = end - (u32) dst;
     memcpy(dst, src, size);
 }

diff --git a/src/hasm/math_util.s b/src/hasm/math_util.s
diff --git a/src/math_util.h b/src/math_util.h
@@ -64,7 +64,7 @@ void mtxf_from_translation(MtxF *mtx, f32 x, f32 y, f32 z);
 void mtxf_from_scale(MtxF *mtx, f32 scaleX, f32 scaleY, f32 scaleZ);
 s32 atan2s(s32 xDelta, s32 zDelta);
 f32 area_triangle_2d(f32 x0, f32 z0, f32 x1, f32 z1, f32 x2, f32 z2);
-void dmacopy_doubleword(void *src, void *dst, s32 end);
+void dmacopy_doubleword(void *src, void *dst, u32 end);
 StackInfo *stack_pointer(void);
 /**
  * Zero out the interrupt mask. This stops this thread

diff --git a/src/thread3_main.c b/src/thread3_main.c
@@ -348,7 +348,7 @@ void main_game_loop(void) {
         if (osTvType == OS_TV_TYPE_PAL) {
             framebufferSize = (s32) ((SCREEN_WIDTH * SCREEN_HEIGHT * 2) * 1.1f);
         }
-        dmacopy_doubleword(gVideoLastFramebuffer, gVideoCurrFramebuffer, (s32) gVideoCurrFramebuffer + framebufferSize);
+        dmacopy_doubleword(gVideoLastFramebuffer, gVideoCurrFramebuffer, (u32) gVideoCurrFramebuffer + framebufferSize);
     }
     // tempLogicUpdateRate will be set to a value 2 or higher, based on the framerate.
     // the mul factor is hardcapped at 6, which happens at 10FPS. The mul factor

diff --git a/ver/splat/dkr.jpn.v79.yaml b/ver/splat/dkr.jpn.v79.yaml
@@ -80,7 +80,7 @@ segments:
       - [0x6ADD0, c, joypad]
       - [0x6B380, c, game]
       - [0x6D000, c, thread3_main]
-      - [0x701F0, hasm, hasm/math_util]
+      - [0x701F0, hasm, hasm/ido/math_util]
       - [0x71810, c, memory]
       - [0x72A10, c, ../libultra/src/io/motor]
       - [0x72F30, c, save_data]
@@ -290,7 +290,7 @@ segments:
       - [0xDF8A0, .data, joypad]
       - [0xDF8B0, .data, game]
       - [0xDF8E0, .data, thread3_main]
-      - [0xDF9D0, .data, hasm/math_util]
+      - [0xDF9D0, .data, hasm/ido/math_util]
       - [0xE09E0, .data, save_data]
       - [0xE0A40, .data, rcp_dkr]
       - [0xE0CE0, .data, ../libultra/src/sc/sched]

diff --git a/ver/splat/dkr.pal.v77.yaml b/ver/splat/dkr.pal.v77.yaml
@@ -80,7 +80,7 @@ segments:
       - [0x6AD00, c, joypad]
       - [0x6B2B0, c, game]
       - [0x6CF30, c, thread3_main]
-      - [0x70110, hasm, hasm/math_util]
+      - [0x70110, hasm, hasm/ido/math_util]
       - [0x71730, c, memory]
       - [0x72930, c, ../libultra/src/io/motor]
       - [0x72E50, c, save_data]
@@ -290,7 +290,7 @@ segments:
       - [0xDDF90, .data, joypad]
       - [0xDDFA0, .data, game]
       - [0xDDFD0, .data, thread3_main]
-      - [0xDE0C0, .data, hasm/math_util]
+      - [0xDE0C0, .data, hasm/ido/math_util]
       - [0xDF0D0, .data, save_data]
       - [0xDF120, .data, rcp_dkr]
       - [0xDF3C0, .data, ../libultra/src/sc/sched]

diff --git a/ver/splat/dkr.pal.v80.yaml b/ver/splat/dkr.pal.v80.yaml
@@ -80,7 +80,7 @@ segments:
       - [0x6AF40, c, joypad]
       - [0x6B4F0, c, game]
       - [0x6D170, c, thread3_main]
-      - [0x70350, hasm, hasm/math_util]
+      - [0x70350, hasm, hasm/ido/math_util]
       - [0x71970, c, memory]
       - [0x72B70, c, ../libultra/src/io/motor]
       - [0x73090, c, save_data]
@@ -290,7 +290,7 @@ segments:
       - [0xDE500, .data, joypad]
       - [0xDE510, .data, game]
       - [0xDE540, .data, thread3_main]
-      - [0xDE630, .data, hasm/math_util]
+      - [0xDE630, .data, hasm/ido/math_util]
       - [0xDF640, .data, save_data]
       - [0xDF6A0, .data, rcp_dkr]
       - [0xDF940, .data, ../libultra/src/sc/sched]

diff --git a/ver/splat/dkr.us.v77.yaml b/ver/splat/dkr.us.v77.yaml
@@ -80,7 +80,7 @@ segments:
       - [0x6AD00, c, joypad]
       - [0x6B2B0, c, game]
       - [0x6CF30, c, thread3_main]
-      - [0x70110, hasm, hasm/math_util]
+      - [0x70110, hasm, hasm/ido/math_util]
       - [0x71730, c, memory]
       - [0x72930, c, ../libultra/src/io/motor]
       - [0x72E50, c, save_data]
@@ -290,7 +290,7 @@ segments:
       - [0xDDF00, .data, joypad]
       - [0xDDF10, .data, game]
       - [0xDDF40, .data, thread3_main]
-      - [0xDE030, .data, hasm/math_util]
+      - [0xDE030, .data, hasm/ido/math_util]
       - [0xDF040, .data, save_data]
       - [0xDF090, .data, rcp_dkr]
       - [0xDF330, .data, ../libultra/src/sc/sched]

diff --git a/ver/splat/dkr.us.v80.yaml b/ver/splat/dkr.us.v80.yaml
@@ -80,7 +80,7 @@ segments:
       - [0x6AF40, c, joypad]
       - [0x6B4F0, c, game]
       - [0x6D170, c, thread3_main]
-      - [0x70350, hasm, hasm/math_util]
+      - [0x70350, hasm, hasm/ido/math_util]
       - [0x71970, c, memory]
       - [0x72B70, c, ../libultra/src/io/motor]
       - [0x73090, c, save_data]
@@ -290,7 +290,7 @@ segments:
       - [0xDE470, .data, joypad]
       - [0xDE480, .data, game]
       - [0xDE4B0, .data, thread3_main]
-      - [0xDE5A0, .data, hasm/math_util]
+      - [0xDE5A0, .data, hasm/ido/math_util]
       - [0xDF5B0, .data, save_data]
       - [0xDF610, .data, rcp_dkr]
       - [0xDF8B0, .data, ../libultra/src/sc/sched]

diff --git a/ver/symbols/symbol_addrs.jpn.v79.txt b/ver/symbols/symbol_addrs.jpn.v79.txt
@@ -1089,7 +1089,6 @@ sins_s16 = 0x80070910;
 coss_2 = 0x8007096C;
 sins_2 = 0x80070970;
 calc_dyn_lighting_for_level_segment = 0x800709B0;
-func_80070A04 = 0x80070AE4;
 area_triangle_2d = 0x80070B0C;
 set_breakpoint = 0x80070BB8;
 dmacopy_doubleword = 0x80070BE4;

diff --git a/ver/symbols/symbol_addrs.pal.v77.txt b/ver/symbols/symbol_addrs.pal.v77.txt
@@ -1087,7 +1087,6 @@ sins_s16 = 0x80070830;
 coss_2 = 0x8007088C;
 sins_2 = 0x80070890;
 calc_dyn_lighting_for_level_segment = 0x800708D0;
-func_80070A04 = 0x80070A04;
 area_triangle_2d = 0x80070A2C;
 set_breakpoint = 0x80070AD8;
 dmacopy_doubleword = 0x80070B04;

diff --git a/ver/symbols/symbol_addrs.pal.v80.txt b/ver/symbols/symbol_addrs.pal.v80.txt
@@ -1025,7 +1025,6 @@ sins_s16 = 0x80070A70;
 coss_2 = 0x80070ACC;
 sins_2 = 0x80070AD0;
 calc_dyn_lighting_for_level_segment = 0x80070B10;
-func_80070A04 = 0x80070C44;
 area_triangle_2d = 0x80070C6C;
 set_breakpoint = 0x80070D18;
 dmacopy_doubleword = 0x80070D44;

diff --git a/ver/symbols/symbol_addrs.us.v77.txt b/ver/symbols/symbol_addrs.us.v77.txt
@@ -1087,7 +1087,6 @@ sins_s16 = 0x80070830;
 coss_2 = 0x8007088C;
 sins_2 = 0x80070890;
 calc_dyn_lighting_for_level_segment = 0x800708D0;
-func_80070A04 = 0x80070A04;
 area_triangle_2d = 0x80070A2C;
 set_breakpoint = 0x80070AD8;
 dmacopy_doubleword = 0x80070B04;

diff --git a/ver/symbols/symbol_addrs.us.v80.txt b/ver/symbols/symbol_addrs.us.v80.txt
@@ -1025,7 +1025,6 @@ sins_s16 = 0x80070A70;
 coss_2 = 0x80070ACC;
 sins_2 = 0x80070AD0;
 calc_dyn_lighting_for_level_segment = 0x80070B10;
-func_80070A04 = 0x80070C44;
 area_triangle_2d = 0x80070C6C;
 set_breakpoint = 0x80070D18;
 dmacopy_doubleword = 0x80070D44;