/**************************************************************************
*
* Copyright 2010, VMware, inc.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
* IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**************************************************************************/
static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
struct draw_vertex_info *info,
const struct draw_prim_info *prim_info )
{
struct vertex_header *out = info->verts;
/* const */ float (*plane)[4] = pvs->draw->plane;
const unsigned pos = draw_current_shader_position_output(pvs->draw);
const unsigned cv = draw_current_shader_clipvertex_output(pvs->draw);
unsigned cd[2];
const unsigned ef = pvs->draw->vs.edgeflag_output;
unsigned ucp_enable = pvs->draw->rasterizer->clip_plane_enable;
unsigned flags = (FLAGS);
unsigned need_pipeline = 0;
unsigned j;
unsigned i;
bool have_cd = false;
unsigned viewport_index_output =
draw_current_shader_viewport_index_output(pvs->draw);
int viewport_index =
draw_current_shader_uses_viewport_index(pvs->draw) ?
*((unsigned*)out->data[viewport_index_output]): 0;
int num_written_clipdistance =
draw_current_shader_num_written_clipdistances(pvs->draw);
cd[0] = draw_current_shader_clipdistance_output(pvs->draw, 0);
cd[1] = draw_current_shader_clipdistance_output(pvs->draw, 1);
if (cd[0] != pos || cd[1] != pos)
have_cd = true;
/* If clipdistance semantic has been written by the shader
* that means we're expected to do 'user plane clipping' */
if (num_written_clipdistance && !(flags & DO_CLIP_USER)) {
flags |= DO_CLIP_USER;
ucp_enable = (1 << num_written_clipdistance) - 1;
}
for (j = 0; j < info->count; j++) {
float *position = out->data[pos];
unsigned mask = 0x0;
float *scale = pvs->draw->viewports[0].scale;
float *trans = pvs->draw->viewports[0].translate;
if (draw_current_shader_uses_viewport_index(pvs->draw)) {
unsigned verts_per_prim = u_vertices_per_prim(prim_info->prim);
/* only change the viewport_index for the leading vertex */
if (!(j % verts_per_prim)) {
viewport_index = *((unsigned*)out->data[viewport_index_output]);
viewport_index = draw_clamp_viewport_idx(viewport_index);
}
scale = pvs->draw->viewports[viewport_index].scale;
trans = pvs->draw->viewports[viewport_index].translate;
}
initialize_vertex_header(out);
if (flags & (DO_CLIP_XY | DO_CLIP_XY_GUARD_BAND |
DO_CLIP_FULL_Z | DO_CLIP_HALF_Z | DO_CLIP_USER)) {
float *clipvertex = position;
if ((flags & DO_CLIP_USER) && cv != pos)
clipvertex = out->data[cv];
for (i = 0; i < 4; i++) {
out->clip[i] = clipvertex[i];
out->pre_clip_pos[i] = position[i];
}
/* Do the hardwired planes first:
*/
if (flags & DO_CLIP_XY_GUARD_BAND) {
if (-0.50 * position[0] + position[3] < 0) mask |= (1<<0);
if ( 0.50 * position[0] + position[3] < 0) mask |= (1<<1);
if (-0.50 * position[1] + position[3] < 0) mask |= (1<<2);
if ( 0.50 * position[1] + position[3] < 0) mask |= (1<<3);
}
else if (flags & DO_CLIP_XY) {
if (-position[0] + position[3] < 0) mask |= (1<<0);
if ( position[0] + position[3] < 0) mask |= (1<<1);
if (-position[1] + position[3] < 0) mask |= (1<<2);
if ( position[1] + position[3] < 0) mask |= (1<<3);
}
/* Clip Z planes according to full cube, half cube or none.
*/
if (flags & DO_CLIP_FULL_Z) {
if ( position[2] + position[3] < 0) mask |= (1<<4);
if (-position[2] + position[3] < 0) mask |= (1<<5);
}
else if (flags & DO_CLIP_HALF_Z) {
if ( position[2] < 0) mask |= (1<<4);
if (-position[2] + position[3] < 0) mask |= (1<<5);
}
if (flags & DO_CLIP_USER) {
unsigned ucp_mask = ucp_enable;
while (ucp_mask) {
unsigned plane_idx = ffs(ucp_mask)-1;
ucp_mask &= ~(1 << plane_idx);
plane_idx += 6;
/*
* for user clipping check if we have a clip distance output
* and the shader has written to it, otherwise use clipvertex
* to decide when the plane is clipping.
*/
if (have_cd && num_written_clipdistance) {
float clipdist;
i = plane_idx - 6;
out->have_clipdist = 1;
/* first four clip distance in first vector etc. */
if (i < 4)
clipdist = out->data[cd[0]][i];
else
clipdist = out->data[cd[1]][i-4];
if (clipdist < 0)
mask |= 1 << plane_idx;
} else {
if (dot4(clipvertex, plane[plane_idx]) < 0)
mask |= 1 << plane_idx;
}
}
}
out->clipmask = mask;
need_pipeline |= out->clipmask;
}
/*
* Transform the vertex position from clip coords to window coords,
* if the vertex is unclipped.
*/
if ((flags & DO_VIEWPORT) && mask == 0)
{
/* divide by w */
float w = 1.0f / position[3];
/* Viewport mapping */
position[0] = position[0] * w * scale[0] + trans[0];
position[1] = position[1] * w * scale[1] + trans[1];
position[2] = position[2] * w * scale[2] + trans[2];
position[3] = w;
}
#ifdef DEBUG
/* For debug builds, set the clipped vertex's window coordinate
* to NaN to help catch potential errors later.
*/
else {
float zero = 0.0f;
position[0] =
position[1] =
position[2] =
position[3] = zero / zero; /* MSVC doesn't accept 0.0 / 0.0 */
}
#endif
if ((flags & DO_EDGEFLAG) && ef) {
const float *edgeflag = out->data[ef];
out->edgeflag = !(edgeflag[0] != 1.0f);
need_pipeline |= !out->edgeflag;
}
out = (struct vertex_header *)( (char *)out + info->stride );
}
return need_pipeline != 0;
}
#undef FLAGS
#undef TAG