Add API function export for camera Z-targeting fixes (#503)

patches/camera_patches.c

@@ -9,6 +9,8 @@
 #include "z64shrink_window.h"
 #include "z64player.h"
 
+static bool camera_fixes = false;
+
 static bool prev_analog_cam_active = false;
 static bool can_use_analog_cam = false;
 static bool analog_cam_active = false;
@@ -26,6 +28,10 @@ float analog_camera_y_sensitivity = 500.0f;
 
 static const float analog_cam_threshold = 0.1f;
 
+RECOMP_EXPORT void recomp_set_camera_fixes(bool new_val) {
+    camera_fixes = new_val;
+}
+
 void update_analog_camera_params(Camera* camera) {
     // recomp_printf("Camera at: %.2f %.2f %.2f\n"
     //               "      eye: %.2f %.2f %.2f\n"
@@ -1064,6 +1070,10 @@ RECOMP_PATCH s32 Camera_Jump2(Camera* camera) {
  */
 // @recomp Patched for analog cam.
 RECOMP_PATCH s32 Camera_Parallel1(Camera* camera) {
+    // @recomp
+    static bool prev_targeting_held = false;
+    bool isChargingDekuFlowerDive = !!(((Player*)camera->focalActor)->stateFlags3 & PLAYER_STATE3_100);
+
     Vec3f* eye = &camera->eye;
     Vec3f* at = &camera->at;
     Vec3f* eyeNext = &camera->eyeNext;
@@ -1089,6 +1099,10 @@ RECOMP_PATCH s32 Camera_Parallel1(Camera* camera) {
     CameraModeValue* values;
     f32 yNormal;
 
+    // @recomp Read timer4 from timer2.
+    s16 timer4 = rwData->timer2 >> 5; // @recomp Used to check if z-target can be quit. Mirrors timer2 values during z-target in unmodified function.
+    rwData->timer2 &= 0x001F;
+
     if (!RELOAD_PARAMS(camera)) {
     } else {
         values = sCameraSettings[camera->setting].cameraModes[camera->mode].values;
@@ -1151,6 +1165,8 @@ RECOMP_PATCH s32 Camera_Parallel1(Camera* camera) {
                 rwData->timer2 = 20;
             } else {
                 rwData->timer2 = 6;
+                // @recomp Initiate timer4 for z-target.
+                timer4 = 6;
             }
 
             if ((camera->focalActor == &GET_PLAYER(camera->play)->actor) && (camera->mode == CAM_MODE_CHARGE)) {
@@ -1187,12 +1203,55 @@ RECOMP_PATCH s32 Camera_Parallel1(Camera* camera) {
             rwData->unk_26 = 1;
             camera->animState = 1;
             sCameraInterfaceFlags = roData->interfaceFlags;
+
+            // @recomp Reset prev_targeting_held after transition.
+            prev_targeting_held = false;
+
             break;
     }
 
+    // @recomp Change behavior for z-target only.
+    if (camera_fixes) {
+        if ((roData->interfaceFlags & (PARALLEL1_FLAG_3 | PARALLEL1_FLAG_2 | PARALLEL1_FLAG_1)) == PARALLEL1_FLAG_1) {
+            Player* player = GET_PLAYER(camera->play);
+            bool targeting_held = func_80123434(player) || player->lockOnActor != NULL;
+
+            // @recomp Fix camera rotating with player if z-target gets released too fast after transition.
+            if ((targeting_held) && (!prev_targeting_held)) {
+                // @recomp Reset timer2 to avoid immediate rotation, if player presses, releases and presses z-target in a very short time-window.
+                rwData->timer2 = 6;
+                rwData->unk_1E = BINANG_ROT180(camera->focalActorPosRot.rot.y) + roData->unk_22;
+            }
+
+            // @recomp Maintain vanilla behavior for quitting z-target.
+            if ((timer4 == 0) && (!targeting_held)) {
+                rwData->timer2 = 0;
+            }
+
+            // @recomp Decrease timer4 only in cases where timer2 would be decreased.
+            if ((timer4 > 0)
+            && (rwData->timer3 <= 0)) {
+                timer4--;
+            }
+
+            prev_targeting_held = targeting_held;
+        }
+    }
+
     if (rwData->timer2 != 0) {
         switch (roData->interfaceFlags & (PARALLEL1_FLAG_3 | PARALLEL1_FLAG_2 | PARALLEL1_FLAG_1)) {
             case PARALLEL1_FLAG_1:
+                if (camera_fixes) {
+                    // @recomp Fix camera rotating with player if z-target gets released too fast after transition.
+                    if (isChargingDekuFlowerDive) {
+                        // @recomp Fix camera wiggle during dive into deku flower.
+                        rwData->unk_1E = BINANG_ROT180(camera->focalActorPosRot.rot.y) + roData->unk_22;
+                    }
+                    rwData->unk_20 = roData->unk_20;
+                    break;
+                }
+                // @recomp fallthrough
+
             case (PARALLEL1_FLAG_3 | PARALLEL1_FLAG_2 | PARALLEL1_FLAG_1):
                 rwData->unk_1E = BINANG_ROT180(camera->focalActorPosRot.rot.y) + roData->unk_22;
                 rwData->unk_20 = roData->unk_20;
@@ -1400,10 +1459,20 @@ RECOMP_PATCH s32 Camera_Parallel1(Camera* camera) {
             func_800CBFA4(camera, at, eye, 3);
         }
 
-        if (rwData->timer2 != 0) {
+        if (camera_fixes) {
-            sUpdateCameraDirection = true;
+            // @recomp Fix camera not updating input dir for the first few frames after transition.
+            if ((isChargingDekuFlowerDive) && (rwData->timer2 != 0)) {
+                // @recomp Fix camera wiggle during dive into deku flower.
+                sUpdateCameraDirection = true;
+            } else {
+                sUpdateCameraDirection = false;
+            }
         } else {
-            sUpdateCameraDirection = false;
+            if (rwData->timer2 != 0) {
+                sUpdateCameraDirection = true;
+            } else {
+                sUpdateCameraDirection = false;
+            }
         }
     }
 
@@ -1412,6 +1481,9 @@ RECOMP_PATCH s32 Camera_Parallel1(Camera* camera) {
     camera->atLerpStepScale = Camera_ClampLerpScale(camera, sp72 ? roData->unk_1C : roData->unk_18);
     rwData->unk_26 &= ~1;
 
+    // @recomp Save timer4 in unused bits of timer2.
+    rwData->timer2 |= timer4 << 5;
+
     return 1;
 }