Decompile Library Background Parallax Entities (#2177)

Decompiles background bookcase, chairs & desk, & shadows behind the
ectoplasms.

Split library background into a separate segment.

config/splat.us.stlib.yaml

@@ -38,6 +38,8 @@ segments:
     subalign: 4
     subsegments:
       - [0x0, data]
+      - [0xDC0, .data, e_library_bg]
+      - [0xDF0, data, unk_2FA80]
       - [0x134C, .data, e_shop]
       - [0x1528, data]
       - [0x1C7C, .data, st_update]
@@ -55,6 +57,7 @@ segments:
       - [0x2C48, .data, e_skeleton]
       - [0x2D38, data]
       - [0x2B938, .rodata, first_c_file]
+      - [0x2B960, .rodata, unk_2FA80]
       - [0x2CE78, .rodata, e_shop]
       - [0x2CF14, .rodata, unk_33EC8]
       - [0x2CF48, .rodata, unk_3420C]
@@ -79,6 +82,8 @@ segments:
       - [0x2DDAC, .rodata, e_spellbook_magic_tome]
       - [0x2DEB4, .rodata, e_life_up]
       - [0x2DED0, c, first_c_file]
+      - [0x2F280, c, e_library_bg]
+      - [0x2FA80, c, unk_2FA80]
       - [0x3245C, c, e_shop]
       - [0x33EC8, c, unk_33EC8]
       - [0x3420C, c, unk_3420C]

config/symbols.us.stlib.txt

@@ -57,9 +57,12 @@ bone_projectile_velocity_x = 0x80182CF4;
 sensors_special = 0x80182D24;
 sensors_move = 0x80182D2C;
 g_UnkPrimHelperRot = 0x801ADDA4;
-ST0_EntityBackgroundBlock = 0x801ADED0;
+LIB_EntityBackgroundBlock = 0x801ADED0;
 PlayerIsWithinHitbox = 0x801ADF98;
 func_801B0AA4 = 0x801AE01C;
+EntityBackgroundBookcase = 0x801AF280;
+EntityBackgroundFurniture = 0x801AF538;
+EntityBackgroundShadow = 0x801AF7B8;
 EntityLibrarianChair = 0x801B037C;
 CutsceneUnk1 = 0x801B95EC;
 SetCutsceneScript = 0x801B9640;

include/entity.h

@@ -2798,6 +2798,11 @@ typedef struct {
     /* 0xA8 */ s16 unkA8;
 } ET_801D2274;
 
+typedef struct {
+    /* 0x7C */ Primitive* prim;
+    /* 0x80 */ Primitive* lastPrim;
+} ET_LibraryShadow;
+
 typedef union { // offset=0x7C
     struct Primitive* prim;
     ET_Placeholder ILLEGAL;
@@ -3041,6 +3046,7 @@ typedef union { // offset=0x7C
     ET_801D064C et_801D064C;
     ET_801D2274 et_801D2274;
     ET_LibrarianChair libraryChair;
+    ET_LibraryShadow libraryShadow;
 } Ext;
 
 #define SYNC_FIELD(struct1, struct2, field)                                    \

src/st/lib/e_library_bg.c

@@ -0,0 +1,277 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+#include "lib.h"
+
+static SVECTOR D_us_80180DC0 = {0, 0, 512};
+static SVECTOR D_us_80180DC8 = {0, 0, 0};
+
+// parallax book cases
+void EntityBackgroundBookcase(Entity* self) {
+    Primitive* prim;
+    s32 primIndex;
+    long p, flag;
+    s16 x;
+    long sxy;
+    SVECTOR svector;
+    VECTOR vector;
+    MATRIX matrix;
+
+    switch (self->step) {
+    case 0:
+        InitializeEntity(g_EInitInteractable);
+        primIndex = g_api.AllocPrimitives(PRIM_GT4, 4);
+        if (primIndex != -1) {
+            self->flags |= FLAG_HAS_PRIMS;
+            self->primIndex = primIndex;
+            prim = &g_PrimBuf[primIndex];
+            self->ext.prim = prim;
+            while (prim != NULL) {
+                prim->tpage = 0xF;
+                prim->clut = 0x35;
+                prim->u0 = prim->u2 = 130;
+                prim->u1 = prim->u3 = 253;
+                prim->v0 = prim->v1 = 50;
+                prim->v2 = prim->v3 = 125;
+                prim->priority = 0x40;
+                prim->drawMode = DRAW_UNK02;
+                prim = prim->next;
+            }
+        } else {
+            DestroyEntity(self);
+            return;
+        }
+        g_GpuBuffers[0].draw.r0 = 16;
+        g_GpuBuffers[0].draw.g0 = 16;
+        g_GpuBuffers[0].draw.b0 = 16;
+        g_GpuBuffers[1].draw.r0 = 16;
+        g_GpuBuffers[1].draw.g0 = 16;
+        g_GpuBuffers[1].draw.b0 = 16;
+        // fallthrough
+    case 1:
+        SetGeomScreen(1024);
+        SetGeomOffset(128, self->posY.i.hi);
+        RotMatrix(&D_us_80180DC8, &matrix);
+        vector.vx = self->posX.i.hi - 128;
+        vector.vy = 0;
+        vector.vz = 1024;
+        TransMatrix(&matrix, &vector);
+        SetRotMatrix(&matrix);
+        SetTransMatrix(&matrix);
+        RotTransPers(&D_us_80180DC0, &sxy, &p, &flag);
+
+        x = sxy & 0xFFFF;
+        if (x > 0) {
+            while (x > -64) {
+                x -= 124;
+            }
+        } else {
+            while (x < -128) {
+                x += 124;
+            }
+        }
+
+        prim = self->ext.prim;
+        while (prim != NULL) {
+            prim->x0 = prim->x2 = x;
+            x += 124;
+            prim->x1 = prim->x3 = x;
+            prim->y0 = prim->y1 = self->posY.i.hi - 76;
+            prim->y2 = prim->y3 = self->posY.i.hi;
+            prim->drawMode = DRAW_UNK02;
+
+            prim = prim->next;
+            if (x > 256) {
+                break;
+            }
+        }
+
+        while (prim != NULL) {
+            prim->drawMode = DRAW_HIDE;
+            prim = prim->next;
+        }
+        break;
+    }
+}
+
+static SVECTOR D_us_80180DD0 = {0, 0, 256};
+static SVECTOR D_us_80180DD8 = {0, 0, 0};
+
+// parallax desk & chairs
+void EntityBackgroundFurniture(Entity* self) {
+    Primitive* prim;
+    s32 primIndex;
+    long p, flag;
+    s16 x;
+    long sxy;
+    SVECTOR svector;
+    VECTOR vector;
+    MATRIX matrix;
+
+    switch (self->step) {
+    case 0:
+        InitializeEntity(g_EInitInteractable);
+        primIndex = g_api.AllocPrimitives(PRIM_GT4, 4);
+        if (primIndex != -1) {
+            self->flags |= FLAG_HAS_PRIMS;
+            self->primIndex = primIndex;
+            prim = &g_PrimBuf[primIndex];
+            self->ext.prim = prim;
+            while (prim != NULL) {
+                prim->tpage = 0xF;
+                prim->clut = 0x34;
+                prim->u0 = prim->u2 = 128;
+                prim->u1 = prim->u3 = 248;
+                prim->v0 = prim->v1 = 0;
+                prim->v2 = prim->v3 = 28;
+                prim->priority = 0x50;
+                prim->drawMode = DRAW_UNK02;
+                prim = prim->next;
+            }
+        } else {
+            DestroyEntity(self);
+            return;
+        }
+        // fallthrough
+    case 1:
+        SetGeomScreen(1024);
+        SetGeomOffset(128, self->posY.i.hi);
+        RotMatrix(&D_us_80180DD8, &matrix);
+        vector.vx = self->posX.i.hi - 128;
+        vector.vy = 0;
+        vector.vz = 1024;
+        TransMatrix(&matrix, &vector);
+        SetRotMatrix(&matrix);
+        SetTransMatrix(&matrix);
+        RotTransPers(&D_us_80180DD0, &sxy, &p, &flag);
+
+        x = sxy & 0xFFFF;
+        if (x > 0) {
+            while (x > -64) {
+                x -= 120;
+            }
+        } else {
+            while (x < -128) {
+                x += 120;
+            }
+        }
+
+        prim = self->ext.prim;
+        while (prim != NULL) {
+            prim->x0 = prim->x2 = x;
+            x += 120;
+            prim->x1 = prim->x3 = x;
+            prim->y0 = prim->y1 = self->posY.i.hi - 28;
+            prim->y2 = prim->y3 = self->posY.i.hi;
+            prim->drawMode = DRAW_UNK02;
+
+            prim = prim->next;
+            if (x > 256) {
+                break;
+            }
+        }
+
+        while (prim != NULL) {
+            prim->drawMode = DRAW_HIDE;
+            prim = prim->next;
+        }
+        break;
+    }
+}
+
+static SVECTOR D_us_80180DE0 = {0, 0, 448};
+static SVECTOR D_us_80180DE8 = {0, 0, 0};
+
+// parallax column shadow
+void EntityBackgroundShadow(Entity* self) {
+    Primitive *prim, *last;
+    s32 primIndex;
+    long p, flag;
+    s16 x;
+    long sxy;
+    SVECTOR svector;
+    VECTOR vector;
+    MATRIX matrix;
+
+    switch (self->step) {
+    case 0:
+        InitializeEntity(g_EInitInteractable);
+        primIndex = g_api.func_800EDB58(PRIM_TILE_ALT, 10);
+        if (primIndex != -1) {
+            self->flags |= FLAG_HAS_PRIMS;
+            self->primIndex = primIndex;
+            prim = &g_PrimBuf[primIndex];
+            self->ext.libraryShadow.prim = prim;
+            while (prim != NULL) {
+                last = prim;
+                prim->u0 = 24;
+                prim->v0 = 64;
+                prim->r0 = prim->g0 = prim->b0 = 0;
+                prim->priority = 0x60;
+                prim->drawMode = DRAW_TPAGE | DRAW_UNK02 | DRAW_TRANSP;
+                prim = prim->next;
+            }
+            prim = last;
+            self->ext.libraryShadow.lastPrim = prim;
+            prim->u0 = 255;
+            prim->v0 = 48;
+            prim->x0 = 0;
+            prim->y0 = self->posY.i.hi - 112;
+            prim->r0 = prim->g0 = prim->b0 = 0;
+            prim->priority = 0x60;
+            prim->drawMode = DRAW_TPAGE | DRAW_UNK02 | DRAW_TRANSP;
+        } else {
+            DestroyEntity(self);
+            return;
+        }
+        // fallthrough
+    case 1:
+        SetGeomScreen(1024);
+        SetGeomOffset(128, self->posY.i.hi);
+        RotMatrix(&D_us_80180DE8, &matrix);
+        vector.vx = self->posX.i.hi - 128;
+        vector.vy = 0;
+        vector.vz = 1024;
+        TransMatrix(&matrix, &vector);
+        SetRotMatrix(&matrix);
+        SetTransMatrix(&matrix);
+        RotTransPers(&D_us_80180DE0, &sxy, &p, &flag);
+
+        x = sxy & 0xFFFF;
+        if (x > 0) {
+            while (x > -64) {
+                x -= 56;
+            }
+        } else {
+            while (x < -128) {
+                x += 56;
+            }
+        }
+
+        prim = self->ext.libraryShadow.prim;
+        while (prim != NULL) {
+            prim->x0 = x;
+            x += 56;
+            prim->y0 = self->posY.i.hi - 64;
+            prim->drawMode = DRAW_TPAGE | DRAW_UNK02 | DRAW_TRANSP;
+
+            prim = prim->next;
+            if (x > 256) {
+                break;
+            }
+        }
+
+        while (prim != NULL) {
+            prim->drawMode = DRAW_HIDE;
+            prim = prim->next;
+        }
+
+        prim = self->ext.libraryShadow.lastPrim;
+        prim->u0 = 255;
+        prim->v0 = 48;
+        prim->x0 = 0;
+        prim->y0 = self->posY.i.hi - 112;
+        prim->r0 = prim->g0 = prim->b0 = 0;
+        prim->priority = 0x60;
+        prim->drawMode = DRAW_TPAGE | DRAW_UNK02 | DRAW_TRANSP;
+        break;
+    }
+}