sprite tracking distance fix; update inverse view matrix before rendering a scene...

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@7877 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/gl_rmain.c b/gl_rmain.c
index 380c7bec1ae0879ba97915ce4fb4ee23e2f47a08..c01a68859033abf7ea72a760fcf3d722929bf172 100644 (file)
--- a/gl_rmain.c
+++ b/gl_rmain.c
@@ -3404,6 +3404,7 @@ static void R_DrawLocs(void);
 static void R_DrawEntityBBoxes(void);
 void R_RenderScene(qboolean addwaterplanes)
 {
+       Matrix4x4_Invert_Simple(&r_view.inverse_matrix, &r_view.matrix);
        R_UpdateFogColor();
 
        if (addwaterplanes)

diff --git a/r_sprites.c b/r_sprites.c
index 649bf2b7ee195c96f7168a1c263daece1016d532..b41041bdc9d2df4954ba588c6875aa22da742f4f 100644 (file)
--- a/r_sprites.c
+++ b/r_sprites.c
@@ -33,8 +33,15 @@ extern cvar_t r_track_sprites_scaleh;
 
 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_view.origin, bCoord);
+       distance = VectorLength(bCoord);
+
+       // Now get the bCoords :)
        Matrix4x4_Transform(&r_view.inverse_matrix, origin, bCoord);
 
        *edge = 0; // FIXME::should assume edge == 0, which is correct currently
@@ -73,21 +80,43 @@ void R_TrackSprite(const entity_render_t *ent, vec3_t origin, vec3_t left, vec3_
                        else
                                *edge = SIDE_LEFT;
                }
-               // should I add || blah == -0.0f? since -0.0f != 0.0f binary speaking, the FPU shouldn't care though?
-               if(ax == 0.0f)
+               
+               // 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_view.frustum_x*r_view.frustum_x * x*x * ax*ax +
+                                       r_view.frustum_y*r_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_view.origin, origin);
-               VectorMA(origin, 50.0f, r_view.forward, origin);
+               VectorMA(origin, distance, r_view.forward, origin);
                // Move the sprite left / up the screeen height
-               ax = (1.0f / VectorLength(left));
-               ay = (1.0f / VectorLength(up));
-               VectorMA(origin, 50.0f * r_view.frustum_x * x * ax, left, origin);
-               VectorMA(origin, 50.0f * r_view.frustum_y * y * ay, up, origin);
+               VectorMA(origin, distance * r_view.frustum_x * x * ax, left, origin);
+               VectorMA(origin, distance * r_view.frustum_y * y * ay, up, origin);
 
                if(r_track_sprites_flags.integer & TSF_ROTATE_CONTINOUSLY)
                {