+extern cvar_t r_labelsprites_scale;
+extern cvar_t r_labelsprites_roundtopixels;
+extern cvar_t r_track_sprites;
+extern cvar_t r_track_sprites_flags;
+extern cvar_t r_track_sprites_scalew;
+extern cvar_t r_track_sprites_scaleh;
+extern cvar_t r_overheadsprites_perspective;
+extern cvar_t r_overheadsprites_pushback;
+extern cvar_t r_overheadsprites_scalex;
+extern cvar_t r_overheadsprites_scaley;
+
+#define TSF_ROTATE 1
+#define TSF_ROTATE_CONTINOUSLY 2
+
+// use same epsilon as in sv_phys.c, it's not in any header, that's why i redefine it
+// MIN_EPSILON is for accurateness' sake :)
+#ifndef EPSILON
+# define EPSILON (1.0f / 32.0f)
+# define MIN_EPSILON 0.0001f
+#endif
+
+/* R_Track_Sprite
+ If the sprite is out of view, track it.
+ `origin`, `left` and `up` are changed by this function to achive a rotation around
+ the hotspot.
+
+ --blub
+ */
+#define SIDE_TOP 1
+#define SIDE_LEFT 2
+#define SIDE_BOTTOM 3
+#define SIDE_RIGHT 4
+
+void R_TrackSprite(const entity_render_t *ent, vec3_t origin, vec3_t left, vec3_t up, int *edge, float *dir_angle)
+{
+ float distance;
+ vec3_t bCoord; // body coordinates of object
+ unsigned int i;
+
+ // temporarily abuse bCoord as the vector player->sprite-origin
+ VectorSubtract(origin, r_refdef.view.origin, bCoord);
+ distance = VectorLength(bCoord);
+
+ // Now get the bCoords :)
+ Matrix4x4_Transform(&r_refdef.view.inverse_matrix, origin, bCoord);
+
+ *edge = 0; // FIXME::should assume edge == 0, which is correct currently
+ for(i = 0; i < 4; ++i)
+ {
+ if(PlaneDiff(origin, &r_refdef.view.frustum[i]) < -EPSILON)
+ break;
+ }
+
+ // If it wasn't outside a plane, no tracking needed
+ if(i < 4)
+ {
+ float x, y; // screen X and Y coordinates
+ float ax, ay; // absolute coords, used for division
+ // I divide x and y by the greater absolute value to get ranges -1.0 to +1.0
+
+ bCoord[2] *= r_refdef.view.frustum_x;
+ bCoord[1] *= r_refdef.view.frustum_y;
+
+ //Con_Printf("%f %f %f\n", bCoord[0], bCoord[1], bCoord[2]);
+
+ ax = fabs(bCoord[1]);
+ ay = fabs(bCoord[2]);
+ // get the greater value and determine the screen edge it's on
+ if(ax < ay)
+ {
+ ax = ay;
+ // 180 or 0 degrees
+ if(bCoord[2] < 0.0f)
+ *edge = SIDE_BOTTOM;
+ else
+ *edge = SIDE_TOP;
+ } else {
+ if(bCoord[1] < 0.0f)
+ *edge = SIDE_RIGHT;
+ else
+ *edge = SIDE_LEFT;
+ }
+
+ // umm...
+ if(ax < MIN_EPSILON) // this was == 0.0f before --blub
+ ax = MIN_EPSILON;
+ // get the -1 to +1 range
+ x = bCoord[1] / ax;
+ y = bCoord[2] / ax;
+
+ ax = (1.0f / VectorLength(left));
+ ay = (1.0f / VectorLength(up));
+ // Using the placement below the distance of a sprite is
+ // real dist = sqrt(d*d + dfxa*dfxa + dgyb*dgyb)
+ // d is the distance we use
+ // f is frustum X
+ // x is x
+ // a is ax
+ // g is frustum Y
+ // y is y
+ // b is ay
+
+ // real dist (r) shall be d, so
+ // r*r = d*d + dfxa*dfxa + dgyb*dgyb
+ // r*r = d*d * (1 + fxa*fxa + gyb*gyb)
+ // d*d = r*r / (1 + fxa*fxa + gyb*gyb)
+ // d = sqrt(r*r / (1 + fxa*fxa + gyb*gyb))
+ // thus:
+ distance = sqrt((distance*distance) / (1.0 +
+ r_refdef.view.frustum_x*r_refdef.view.frustum_x * x*x * ax*ax +
+ r_refdef.view.frustum_y*r_refdef.view.frustum_y * y*y * ay*ay));
+ // ^ the one we want ^ the one we have ^ our factors
+
+ // Place the sprite a few units ahead of the player
+ VectorCopy(r_refdef.view.origin, origin);
+ VectorMA(origin, distance, r_refdef.view.forward, origin);
+ // Move the sprite left / up the screeen height
+ VectorMA(origin, distance * r_refdef.view.frustum_x * x * ax, left, origin);
+ VectorMA(origin, distance * r_refdef.view.frustum_y * y * ay, up, origin);
+
+ if(r_track_sprites_flags.integer & TSF_ROTATE_CONTINOUSLY)
+ {
+ // compute the rotation, negate y axis, we're pointing outwards
+ *dir_angle = atan(-y / x) * 180.0f/M_PI;
+ // we need the real, full angle
+ if(x < 0.0f)
+ *dir_angle += 180.0f;
+ }
+
+ left[0] *= r_track_sprites_scalew.value;
+ left[1] *= r_track_sprites_scalew.value;
+ left[2] *= r_track_sprites_scalew.value;
+
+ up[0] *= r_track_sprites_scaleh.value;
+ up[1] *= r_track_sprites_scaleh.value;
+ up[2] *= r_track_sprites_scaleh.value;
+ }
+}
+
+void R_RotateSprite(const mspriteframe_t *frame, vec3_t origin, vec3_t left, vec3_t up, int edge, float dir_angle)
+{
+ if(!(r_track_sprites_flags.integer & TSF_ROTATE))
+ {
+ // move down by its size if on top, otherwise it's invisible
+ if(edge == SIDE_TOP)
+ VectorMA(origin, -(fabs(frame->up)+fabs(frame->down)), up, origin);
+ } else {
+ static float rotation_angles[5] =
+ {
+ 0, // no edge
+ -90.0f, //top
+ 0.0f, // left
+ 90.0f, // bottom
+ 180.0f, // right
+ };
+
+ // rotate around the hotspot according to which edge it's on
+ // since the hotspot == the origin, only rotate the vectors
+ matrix4x4_t rotm;
+ vec3_t axis;
+ vec3_t temp;
+ vec2_t dir;
+ float angle;
+
+ if(edge < 1 || edge > 4)
+ return; // this usually means something went wrong somewhere, there's no way to get a wrong edge value currently
+
+ dir[0] = frame->right + frame->left;
+ dir[1] = frame->down + frame->up;
+
+ // only rotate when the hotspot isn't the center though.
+ if(dir[0] < MIN_EPSILON && dir[1] < MIN_EPSILON)
+ {
+ return;
+ }
+
+ // Now that we've kicked center-hotspotted sprites, rotate using the appropriate matrix :)
+
+ // determine the angle of a sprite, we could only do that once though and
+ // add a `qboolean initialized' to the mspriteframe_t struct... let's get the direction vector of it :)
+
+ angle = atan(dir[1] / dir[0]) * 180.0f/M_PI;
+
+ // we need the real, full angle
+ if(dir[0] < 0.0f)
+ angle += 180.0f;
+
+ // Rotate around rotation_angle - frame_angle
+ // The axis SHOULD equal r_refdef.view.forward, but let's generalize this:
+ CrossProduct(up, left, axis);
+ if(r_track_sprites_flags.integer & TSF_ROTATE_CONTINOUSLY)
+ Matrix4x4_CreateRotate(&rotm, dir_angle - angle, axis[0], axis[1], axis[2]);
+ else
+ Matrix4x4_CreateRotate(&rotm, rotation_angles[edge] - angle, axis[0], axis[1], axis[2]);
+ Matrix4x4_Transform(&rotm, up, temp);
+ VectorCopy(temp, up);
+ Matrix4x4_Transform(&rotm, left, temp);
+ VectorCopy(temp, left);
+ }
+}
+
+static float spritetexcoord2f[4*2] = {0, 1, 0, 0, 1, 0, 1, 1};
+