bgaffin rot/scale done

include/sysutil.h

@@ -150,13 +150,14 @@ void NewSysboxText(int vobj_offset, int pal, const char * str, int line, int del
 void EndAllProcChildren(ProcPtr proc);
 void nop_80ADDF8(void);
 
-/* Some objects scalling routine */
-void sub_80ADDFC(u8 layer, s16 angle, s16, s16, s16, s16);
-void sub_80ADE90(u8, s16, s16);
-void sub_80ADEE0(u8, s16, s16, s16, s16);
-void sub_80ADF48(u8 layer, int angle, int a, int b, int c, int d);
-void sub_80ADFBC(u8 layer, int a, int b);
-void sub_80ADFFC(u8 layer, int a, int b, int c, int d);
+/* Bg-affin rot/scale */
+void BgAffinRotScaling(u8 bg, s16 angle, s16 x_center, s16 y_center, s16 sx, s16 sy);
+void BgAffinScaling(u8 bg, s16 sy, s16 sx);
+void BgAffinAnchoring(u8 bg, s16 q0_x, s16 q0_y, s16 p0_x, s16 p0_y);
+
+void BgAffinRotScalingHighPrecision(u8 bg, int angle, int texX, int texY, int sx, int sy);
+void BgAffinScalingHighPrecision(u8 bg, int sy, int sx);
+void BgAffinAnchoringHighPrecision(u8 bg, int q0_x, int q0_y, int p0_x, int p0_y);
 
 /* No idea, maybe some tile map or palette modication */
 void sub_80AE044(int a, u16 * buf, int c, int d, int e, int f, int g, int h);

src/chapterintrofx.c

@@ -611,9 +611,9 @@ void ChapterIntro_LightBurst_Loop(struct ChapterIntroFXProc* proc) {
     }
 
     if (proc->unk_4C <= 0xFF) {
-        sub_80ADDFC(2, 0, 0, 0, 0x180, 0x180);
-        sub_80ADE90(2, (u16)proc->unk_4C + 0xF0, (u16)proc->unk_4C + 0xF0);
-        sub_80ADEE0(2, 0x70, 0x58, 0x4C, 0x4C);
+        BgAffinRotScaling(2, 0, 0, 0, 0x180, 0x180);
+        BgAffinScaling(2, (u16)proc->unk_4C + 0xF0, (u16)proc->unk_4C + 0xF0);
+        BgAffinAnchoring(2, 0x70, 0x58, 0x4C, 0x4C);
         FlushLCDControl();
 
         if (proc->unk_66 != 0) {

src/opinfo.c

@@ -751,11 +751,11 @@ void ClassIntroFlare_Loop(struct OpInfoFlareProc* proc) {
     unkC = Interpolate(0, 0, 0xD6, proc->unk_4c, 0x3C);
     unkD = Interpolate(0, 0x10, 0x80, proc->unk_4c, 0x3C);
 
-    sub_80ADDFC(2, (s16)proc->unk_4e, 0, 0, (s16)(unkA * 5 + 0x80), (s16)(unkA * 5 + 0x80));
+    BgAffinRotScaling(2, (s16)proc->unk_4e, 0, 0, (s16)(unkA * 5 + 0x80), (s16)(unkA * 5 + 0x80));
 
-    sub_80ADE90(2, 0x100, 0x100);
+    BgAffinScaling(2, 0x100, 0x100);
 
-    sub_80ADEE0(2, unkC, unkD, 0x50, 0x48);
+    BgAffinAnchoring(2, unkC, unkD, 0x50, 0x48);
 
     proc->unk_4e -= 0x40;
 

src/opsubtitle.c

@@ -238,9 +238,9 @@ void Subtitle_LightFlareFx_Loop(struct OpSubtitleProc* proc) {
     c = Interpolate(0, 0, 214, proc->unk_4c, 60);
     d = Interpolate(0, 16, 128, proc->unk_4c, 60);
 
-    sub_80ADDFC(2, proc->unk_4e, 0, 0, a * 5 + 0x80, a * 5 + 0x80);
-    sub_80ADE90(2, 0x100, 0x100);
-    sub_80ADEE0(2, c, d, 80, 72);
+    BgAffinRotScaling(2, proc->unk_4e, 0, 0, a * 5 + 0x80, a * 5 + 0x80);
+    BgAffinScaling(2, 0x100, 0x100);
+    BgAffinAnchoring(2, c, d, 80, 72);
 
     proc->unk_4e -= 64;
 

src/sysutil.c

@@ -893,23 +893,23 @@ void nop_80ADDF8(void)
     return;
 }
 
-void sub_80ADDFC(u8 bg, s16 angle, s16 c, s16 d, s16 e, s16 f)
+void BgAffinRotScaling(u8 bg, s16 angle, s16 x_center, s16 y_center, s16 sx, s16 sy)
 {
     struct BgAffineSrcData data;
     struct BgAffineDstData * dst;
 
-    if (e <= 4)
-        e = 4;
+    if (sx <= 4)
+        sx = 4;
 
-    if (f <= 4)
-        f = 4;
+    if (sy <= 4)
+        sy = 4;
 
-    data.texX = c * 0x100;
-    data.texY = d * 0x100;
+    data.texX = x_center * 0x100;
+    data.texY = y_center * 0x100;
     data.scrX = 0;
     data.scrY = 0;
-    data.sx = 0x10000 / e;
-    data.sy = 0x10000 / f;
+    data.sx = 0x10000 / sx;
+    data.sy = 0x10000 / sy;
     data.alpha = angle * 0x10;
 
     dst = &gLCDControlBuffer.bg3affin;
@@ -919,45 +919,64 @@ void sub_80ADDFC(u8 bg, s16 angle, s16 c, s16 d, s16 e, s16 f)
     BgAffineSet(&data, dst, 1);
 }
 
-void sub_80ADE90(u8 bg, s16 a, s16 b)
+void BgAffinScaling(u8 bg, s16 sy, s16 sx)
 {
     struct BgAffineDstData * affin = NULL;
     if (bg == BG_2)
         affin = &gLCDControlBuffer.bg2affin;
 
-    affin->pb = (affin->pb * a) >> 8;
-    affin->pd = (affin->pd * a) >> 8;
-    affin->pa = (affin->pa * b) >> 8;
-    affin->pc = (affin->pc * b) >> 8;
-}
-
-void sub_80ADEE0(u8 bg, s16 a, s16 b, s16 c, s16 d)
-{
+    /**
+     * y = y * (1 / sy)
+     * x = x * (1 / sx)
+     *
+     * Both of which are 8.8 fixed point numbers:
+     * a halfword with 8 integer bits and 8 fractional bits.
+     * 
+     * See tonc 10.4.1: https://www.coranac.com/tonc/text/affine.htm
+     */
+
+    affin->pb = (affin->pb * sy) >> 8;
+    affin->pd = (affin->pd * sy) >> 8;
+    affin->pa = (affin->pa * sx) >> 8;
+    affin->pc = (affin->pc * sx) >> 8;
+}
+
+void BgAffinAnchoring(u8 bg, s16 q0_x, s16 q0_y, s16 p0_x, s16 p0_y)
+{
+    /**
+     * vector q0: origin in screen space
+     * vector p0: origin in texture space
+     *
+     * See tonc 12.3: https://www.coranac.com/tonc/text/affbg.htm:
+     *
+     * bgaff->dx= asx->tex_x - (pa*asx->scr_x + pb*asx->scr_y);
+     * bgaff->dy= asx->tex_y - (pc*asx->scr_x + pd*asx->scr_y);
+     */
     struct BgAffineDstData * affin = NULL;
     if (bg == BG_2)
         affin = &gLCDControlBuffer.bg2affin;
 
-    affin->dx = affin->pa * (-a) + affin->pb * (-b) + c * 0x100;
-    affin->dy = affin->pc * (-a) + affin->pd * (-b) + d * 0x100;
+    affin->dx = affin->pa * (-q0_x) + affin->pb * (-q0_y) + p0_x * 0x100;
+    affin->dy = affin->pc * (-q0_x) + affin->pd * (-q0_y) + p0_y * 0x100;
 }
 
-void sub_80ADF48(u8 bg, int angle, int a, int b, int c, int d)
+void BgAffinRotScalingHighPrecision(u8 bg, int angle, int texX, int texY, int sx, int sy)
 {
     struct BgAffineSrcData data;
     struct BgAffineDstData * dst;
 
-    if (c <= 0x400)
-        c = 0x400;
+    if (sx <= 0x400)
+        sx = 0x400;
 
-    if (d <= 0x400)
-        d = 0x400;
+    if (sy <= 0x400)
+        sy = 0x400;
 
-    data.texX = a;
-    data.texY = b;
+    data.texX = texX;
+    data.texY = texY;
     data.scrX = 0;
     data.scrY = 0;
-    data.sx = 0x1000000 / c;
-    data.sy = 0x1000000 / d;
+    data.sx = 0x1000000 / sx;
+    data.sy = 0x1000000 / sy;
     data.alpha = angle >> 4;
 
     dst = &gLCDControlBuffer.bg3affin;
@@ -967,26 +986,26 @@ void sub_80ADF48(u8 bg, int angle, int a, int b, int c, int d)
     BgAffineSet(&data, dst, 1);
 }
 
-void sub_80ADFBC(u8 bg, int a, int b)
+void BgAffinScalingHighPrecision(u8 bg, int sy, int sx)
 {
     struct BgAffineDstData * affin = NULL;
     if (bg == BG_2)
         affin = &gLCDControlBuffer.bg2affin;
 
-    affin->pb = (affin->pb * a) >> 0x10;
-    affin->pd = (affin->pd * a) >> 0x10;
-    affin->pa = (affin->pa * b) >> 0x10;
-    affin->pc = (affin->pc * b) >> 0x10;
+    affin->pb = (affin->pb * sy) >> 0x10;
+    affin->pd = (affin->pd * sy) >> 0x10;
+    affin->pa = (affin->pa * sx) >> 0x10;
+    affin->pc = (affin->pc * sx) >> 0x10;
 }
 
-void sub_80ADFFC(u8 bg, int a, int b, int c, int d)
+void BgAffinAnchoringHighPrecision(u8 bg, int q0_x, int q0_y, int p0_x, int p0_y)
 {
     struct BgAffineDstData * affin = NULL;
     if (bg == BG_2)
         affin = &gLCDControlBuffer.bg2affin;
 
-    affin->dx = ((affin->pa * (-a) + affin->pb * (-b)) >> 8) + c;
-    affin->dy = ((affin->pc * (-a) + affin->pd * (-b)) >> 8) + d;
+    affin->dx = ((affin->pa * (-q0_x) + affin->pb * (-q0_y)) >> 8) + p0_x;
+    affin->dy = ((affin->pc * (-q0_x) + affin->pd * (-q0_y)) >> 8) + p0_y;
 }
 
 void sub_80AE044(int a, u16 * buf, int c, int d, int e, int f, int g, int h)