/* This is performed against the original triangles, so no indirection
* required:
BZZZT!
*/
static void compute_tri_direction( struct brw_clip_compile *c )
{
struct brw_compile *p = &c->func;
struct brw_reg e = c->reg.tmp0;
struct brw_reg f = c->reg.tmp1;
GLuint hpos_offset = brw_vert_result_to_offset(&c->vue_map,
VARYING_SLOT_POS);
struct brw_reg v0 = byte_offset(c->reg.vertex[0], hpos_offset);
struct brw_reg v1 = byte_offset(c->reg.vertex[1], hpos_offset);
struct brw_reg v2 = byte_offset(c->reg.vertex[2], hpos_offset);
struct brw_reg v0n = get_tmp(c);
struct brw_reg v1n = get_tmp(c);
struct brw_reg v2n = get_tmp(c);
/* Convert to NDC.
* NOTE: We can't modify the original vertex coordinates,
* as it may impact further operations.
* So, we have to keep normalized coordinates in temp registers.
*
* TBD-KC
* Try to optimize unnecessary MOV's.
*/
brw_MOV(p, v0n, v0);
brw_MOV(p, v1n, v1);
brw_MOV(p, v2n, v2);
brw_clip_project_position(c, v0n);
brw_clip_project_position(c, v1n);
brw_clip_project_position(c, v2n);
/* Calculate the vectors of two edges of the triangle:
*/
brw_ADD(p, e, v0n, negate(v2n));
brw_ADD(p, f, v1n, negate(v2n));
/* Take their crossproduct:
*/
brw_set_access_mode(p, BRW_ALIGN_16);
brw_MUL(p, vec4(brw_null_reg()), brw_swizzle(e, 1,2,0,3), brw_swizzle(f,2,0,1,3));
brw_MAC(p, vec4(e), negate(brw_swizzle(e, 2,0,1,3)), brw_swizzle(f,1,2,0,3));
brw_set_access_mode(p, BRW_ALIGN_1);
brw_MUL(p, c->reg.dir, c->reg.dir, vec4(e));
}
static void brw_clip_project_vertex( struct brw_clip_compile *c,
struct brw_indirect vert_addr )
{
struct brw_compile *p = &c->func;
struct brw_reg tmp = get_tmp(c);
/* Fixup position. Extract from the original vertex and re-project
* to screen space:
*/
brw_MOV(p, tmp, deref_4f(vert_addr, c->offset[VERT_RESULT_HPOS]));
brw_clip_project_position(c, tmp);
brw_MOV(p, deref_4f(vert_addr, c->header_position_offset), tmp);
release_tmp(c, tmp);
}
static void brw_clip_project_vertex( struct brw_clip_compile *c,
struct brw_indirect vert_addr )
{
struct brw_codegen *p = &c->func;
struct brw_reg tmp = get_tmp(c);
GLuint hpos_offset = brw_varying_to_offset(&c->vue_map, VARYING_SLOT_POS);
GLuint ndc_offset = brw_varying_to_offset(&c->vue_map,
BRW_VARYING_SLOT_NDC);
/* Fixup position. Extract from the original vertex and re-project
* to screen space:
*/
brw_MOV(p, tmp, deref_4f(vert_addr, hpos_offset));
brw_clip_project_position(c, tmp);
brw_MOV(p, deref_4f(vert_addr, ndc_offset), tmp);
release_tmp(c, tmp);
}
