/* Interpolate between two vertices to produce a third.
*/
static void interp( const struct clipper *clip,
struct vertex_header *dst,
float t,
const struct vertex_header *out,
const struct vertex_header *in )
{
const unsigned nr_attrs = clip->stage.draw->vs.num_vs_outputs;
const unsigned pos_attr = clip->stage.draw->vs.position_output;
unsigned j;
/* Vertex header.
*/
{
dst->clipmask = 0;
dst->edgeflag = 0; /* will get overwritten later */
dst->pad = 0;
dst->vertex_id = UNDEFINED_VERTEX_ID;
}
/* Clip coordinates: interpolate normally
*/
{
interp_attr(dst->clip, t, in->clip, out->clip);
}
/* Do the projective divide and insert window coordinates:
*/
{
const float *pos = dst->clip;
const float *scale = clip->stage.draw->viewport.scale;
const float *trans = clip->stage.draw->viewport.translate;
const float oow = 1.0f / pos[3];
dst->data[pos_attr][0] = pos[0] * oow * scale[0] + trans[0];
dst->data[pos_attr][1] = pos[1] * oow * scale[1] + trans[1];
dst->data[pos_attr][2] = pos[2] * oow * scale[2] + trans[2];
dst->data[pos_attr][3] = oow;
}
/* Other attributes
*/
for (j = 0; j < nr_attrs; j++) {
if (j != pos_attr)
interp_attr(dst->data[j], t, in->data[j], out->data[j]);
}
}
/* Interpolate between two vertices to produce a third.
*/
static void interp( const struct clip_stage *clip,
struct vertex_header *dst,
float t,
const struct vertex_header *out,
const struct vertex_header *in )
{
const unsigned nr_attrs = draw_current_shader_outputs(clip->stage.draw);
const unsigned pos_attr = draw_current_shader_position_output(clip->stage.draw);
unsigned j;
/* Vertex header.
*/
dst->clipmask = 0;
dst->edgeflag = 0; /* will get overwritten later */
dst->pad = 0;
dst->vertex_id = UNDEFINED_VERTEX_ID;
/* Interpolate the clip-space coords.
*/
interp_attr(dst->clip, t, in->clip, out->clip);
/* Do the projective divide and viewport transformation to get
* new window coordinates:
*/
{
const float *pos = dst->clip;
const float *scale = clip->stage.draw->viewport.scale;
const float *trans = clip->stage.draw->viewport.translate;
const float oow = 1.0f / pos[3];
dst->data[pos_attr][0] = pos[0] * oow * scale[0] + trans[0];
dst->data[pos_attr][1] = pos[1] * oow * scale[1] + trans[1];
dst->data[pos_attr][2] = pos[2] * oow * scale[2] + trans[2];
dst->data[pos_attr][3] = oow;
}
/* Other attributes
*/
for (j = 0; j < nr_attrs; j++) {
if (j != pos_attr)
interp_attr(dst->data[j], t, in->data[j], out->data[j]);
}
}
/* Interpolate between two vertices to produce a third.
*/
static void interp( const struct clip_stage *clip,
struct vertex_header *dst,
float t,
const struct vertex_header *out,
const struct vertex_header *in,
unsigned viewport_index )
{
const unsigned nr_attrs = draw_num_shader_outputs(clip->stage.draw);
const unsigned pos_attr = draw_current_shader_position_output(clip->stage.draw);
const unsigned clip_attr = draw_current_shader_clipvertex_output(clip->stage.draw);
unsigned j;
float t_nopersp;
/* Vertex header.
*/
dst->clipmask = 0;
dst->edgeflag = 0; /* will get overwritten later */
dst->have_clipdist = in->have_clipdist;
dst->vertex_id = UNDEFINED_VERTEX_ID;
/* Interpolate the clip-space coords.
*/
interp_attr(dst->clip, t, in->clip, out->clip);
/* interpolate the clip-space position */
interp_attr(dst->pre_clip_pos, t, in->pre_clip_pos, out->pre_clip_pos);
/* Do the projective divide and viewport transformation to get
* new window coordinates:
*/
{
const float *pos = dst->pre_clip_pos;
const float *scale =
clip->stage.draw->viewports[viewport_index].scale;
const float *trans =
clip->stage.draw->viewports[viewport_index].translate;
const float oow = 1.0f / pos[3];
dst->data[pos_attr][0] = pos[0] * oow * scale[0] + trans[0];
dst->data[pos_attr][1] = pos[1] * oow * scale[1] + trans[1];
dst->data[pos_attr][2] = pos[2] * oow * scale[2] + trans[2];
dst->data[pos_attr][3] = oow;
}
/**
* Compute the t in screen-space instead of 3d space to use
* for noperspective interpolation.
*
* The points can be aligned with the X axis, so in that case try
* the Y. When both points are at the same screen position, we can
* pick whatever value (the interpolated point won't be in front
* anyway), so just use the 3d t.
*/
{
int k;
t_nopersp = t;
/* find either in.x != out.x or in.y != out.y */
for (k = 0; k < 2; k++) {
if (in->clip[k] != out->clip[k]) {
/* do divide by W, then compute linear interpolation factor */
float in_coord = in->clip[k] / in->clip[3];
float out_coord = out->clip[k] / out->clip[3];
float dst_coord = dst->clip[k] / dst->clip[3];
t_nopersp = (dst_coord - out_coord) / (in_coord - out_coord);
break;
}
}
}
/* Other attributes
*/
for (j = 0; j < nr_attrs; j++) {
if (j != pos_attr && j != clip_attr) {
if (clip->noperspective_attribs[j])
interp_attr(dst->data[j], t_nopersp, in->data[j], out->data[j]);
else
interp_attr(dst->data[j], t, in->data[j], out->data[j]);
}
}
}
