CL_RotateMoves: helper builtin for Xonotic for perfect warpzone prediction

[xonotic/darkplaces.git] / clvm_cmds.c

diff --git a/clvm_cmds.c b/clvm_cmds.c
index 2beea3ce7efb3b18b9566a010f3bdbdf50a7b84d..ffcff83f7d70760e8fd8b922fc7849fdea8e39b7 100644 (file)
--- a/clvm_cmds.c
+++ b/clvm_cmds.c
@@ -3990,6 +3990,44 @@ static void VM_CL_frameduration(void)
                PRVM_G_FLOAT(OFS_RETURN) = model->animscenes[framenum].framecount / model->animscenes[framenum].framerate;
 }
 
+void VM_CL_RotateMoves(void)
+{
+       /*
+        * Obscure builtin used by GAME_XONOTIC.
+        *
+        * Edits the input history of cl_movement by rotating all move commands
+        * currently in the queue using the given transform.
+        *
+        * The vector passed is an "angles transform" as used by warpzonelib, i.e.
+        * v_angle-like (non-inverted) euler angles that perform the rotation
+        * of the space that is to be done.
+        *
+        * This is meant to be used as a fixangle replacement after passing
+        * through a warpzone/portal: the client is told about the warp transform,
+        * and calls this function in the same frame as the one on which the
+        * client's origin got changed by the serverside teleport. Then this code
+        * transforms the pre-warp input (which matches the empty space behind
+        * the warp plane) into post-warp input (which matches the target area
+        * of the warp). Also, at the same time, the client has to use
+        * R_SetView to adjust VF_CL_VIEWANGLES according to the same transform.
+        *
+        * This together allows warpzone motion to be perfectly predicted by
+        * the client!
+        *
+        * Furthermore, for perfect warpzone behaviour, the server side also
+        * has to detect input the client sent before it received the origin
+        * update, but after the warp occurred on the server, and has to adjust
+        * input appropriately.
+        */
+       matrix4x4_t m;
+       vec3_t v = {0, 0, 0};
+       vec3_t x, y, z;
+       VM_SAFEPARMCOUNT(1, VM_CL_RotateMoves);
+       AngleVectorsFLU(PRVM_G_VECTOR(OFS_PARM0), x, y, z);
+       Matrix4x4_FromVectors(&m, x, y, z, v);
+       CL_RotateMoves(&m);
+}
+
 //============================================================================
 
 // To create a almost working builtin file from this replace:
@@ -4638,6 +4676,12 @@ VM_setkeybind,                                           // #630 float(float key, string bind[, float bindmap]) setke
 VM_getbindmaps,                                                // #631 vector(void) getbindmap
 VM_setbindmaps,                                                // #632 float(vector bm) setbindmap
 NULL,                                                  // #633
+NULL,                                                  // #634
+NULL,                                                  // #635
+NULL,                                                  // #636
+NULL,                                                  // #637
+VM_CL_RotateMoves,                                     // #638
+NULL,                                                  // #639
 };
 
 const int vm_cl_numbuiltins = sizeof(vm_cl_builtins) / sizeof(prvm_builtin_t);