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path: root/src/gallium/drivers/i965simple/brw_clip_line.c
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Diffstat (limited to 'src/gallium/drivers/i965simple/brw_clip_line.c')
-rw-r--r--src/gallium/drivers/i965simple/brw_clip_line.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/src/gallium/drivers/i965simple/brw_clip_line.c b/src/gallium/drivers/i965simple/brw_clip_line.c
new file mode 100644
index 00000000000..75d9e5fcda2
--- /dev/null
+++ b/src/gallium/drivers/i965simple/brw_clip_line.c
@@ -0,0 +1,245 @@
+/*
+ Copyright (C) Intel Corp. 2006. All Rights Reserved.
+ Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to
+ develop this 3D driver.
+
+ 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, sublicense, 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 NONINFRINGEMENT.
+ IN NO EVENT SHALL THE COPYRIGHT OWNER(S) 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.
+
+ **********************************************************************/
+ /*
+ * Authors:
+ * Keith Whitwell <keith@tungstengraphics.com>
+ */
+
+#include "brw_defines.h"
+#include "brw_context.h"
+#include "brw_eu.h"
+#include "brw_util.h"
+#include "brw_clip.h"
+
+
+
+static void brw_clip_line_alloc_regs( struct brw_clip_compile *c )
+{
+ unsigned i = 0,j;
+
+ /* Register usage is static, precompute here:
+ */
+ c->reg.R0 = retype(brw_vec8_grf(i, 0), BRW_REGISTER_TYPE_UD); i++;
+
+ if (c->key.nr_userclip) {
+ c->reg.fixed_planes = brw_vec4_grf(i, 0);
+ i += (6 + c->key.nr_userclip + 1) / 2;
+
+ c->prog_data.curb_read_length = (6 + c->key.nr_userclip + 1) / 2;
+ }
+ else
+ c->prog_data.curb_read_length = 0;
+
+
+ /* Payload vertices plus space for more generated vertices:
+ */
+ for (j = 0; j < 4; j++) {
+ c->reg.vertex[j] = brw_vec4_grf(i, 0);
+ i += c->nr_regs;
+ }
+
+ c->reg.t = brw_vec1_grf(i, 0);
+ c->reg.t0 = brw_vec1_grf(i, 1);
+ c->reg.t1 = brw_vec1_grf(i, 2);
+ c->reg.planemask = retype(brw_vec1_grf(i, 3), BRW_REGISTER_TYPE_UD);
+ c->reg.plane_equation = brw_vec4_grf(i, 4);
+ i++;
+
+ c->reg.dp0 = brw_vec1_grf(i, 0); /* fixme - dp4 will clobber r.1,2,3 */
+ c->reg.dp1 = brw_vec1_grf(i, 4);
+ i++;
+
+ if (!c->key.nr_userclip) {
+ c->reg.fixed_planes = brw_vec8_grf(i, 0);
+ i++;
+ }
+
+
+ c->first_tmp = i;
+ c->last_tmp = i;
+
+ c->prog_data.urb_read_length = c->nr_regs; /* ? */
+ c->prog_data.total_grf = i;
+}
+
+
+
+/* Line clipping, more or less following the following algorithm:
+ *
+ * for (p=0;p<MAX_PLANES;p++) {
+ * if (clipmask & (1 << p)) {
+ * float dp0 = DOTPROD( vtx0, plane[p] );
+ * float dp1 = DOTPROD( vtx1, plane[p] );
+ *
+ * if (IS_NEGATIVE(dp1)) {
+ * float t = dp1 / (dp1 - dp0);
+ * if (t > t1) t1 = t;
+ * } else {
+ * float t = dp0 / (dp0 - dp1);
+ * if (t > t0) t0 = t;
+ * }
+ *
+ * if (t0 + t1 >= 1.0)
+ * return;
+ * }
+ * }
+ *
+ * interp( ctx, newvtx0, vtx0, vtx1, t0 );
+ * interp( ctx, newvtx1, vtx1, vtx0, t1 );
+ *
+ */
+static void clip_and_emit_line( struct brw_clip_compile *c )
+{
+ struct brw_compile *p = &c->func;
+ struct brw_indirect vtx0 = brw_indirect(0, 0);
+ struct brw_indirect vtx1 = brw_indirect(1, 0);
+ struct brw_indirect newvtx0 = brw_indirect(2, 0);
+ struct brw_indirect newvtx1 = brw_indirect(3, 0);
+ struct brw_indirect plane_ptr = brw_indirect(4, 0);
+ struct brw_instruction *plane_loop;
+ struct brw_instruction *plane_active;
+ struct brw_instruction *is_negative;
+ struct brw_instruction *is_neg2;
+ struct brw_instruction *not_culled;
+ struct brw_reg v1_null_ud = retype(vec1(brw_null_reg()), BRW_REGISTER_TYPE_UD);
+
+ brw_MOV(p, get_addr_reg(vtx0), brw_address(c->reg.vertex[0]));
+ brw_MOV(p, get_addr_reg(vtx1), brw_address(c->reg.vertex[1]));
+ brw_MOV(p, get_addr_reg(newvtx0), brw_address(c->reg.vertex[2]));
+ brw_MOV(p, get_addr_reg(newvtx1), brw_address(c->reg.vertex[3]));
+ brw_MOV(p, get_addr_reg(plane_ptr), brw_clip_plane0_address(c));
+
+ /* Note: init t0, t1 together:
+ */
+ brw_MOV(p, vec2(c->reg.t0), brw_imm_f(0));
+
+ brw_clip_init_planes(c);
+ brw_clip_init_clipmask(c);
+
+ /* -ve rhw workaround */
+ brw_set_conditionalmod(p, BRW_CONDITIONAL_NZ);
+ brw_AND(p, brw_null_reg(), get_element_ud(c->reg.R0, 2),
+ brw_imm_ud(1<<20));
+ brw_OR(p, c->reg.planemask, c->reg.planemask, brw_imm_ud(0x3f));
+ brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+
+ plane_loop = brw_DO(p, BRW_EXECUTE_1);
+ {
+ /* if (planemask & 1)
+ */
+ brw_set_conditionalmod(p, BRW_CONDITIONAL_NZ);
+ brw_AND(p, v1_null_ud, c->reg.planemask, brw_imm_ud(1));
+
+ plane_active = brw_IF(p, BRW_EXECUTE_1);
+ {
+ if (c->key.nr_userclip)
+ brw_MOV(p, c->reg.plane_equation, deref_4f(plane_ptr, 0));
+ else
+ brw_MOV(p, c->reg.plane_equation, deref_4b(plane_ptr, 0));
+
+#if 0
+ /* dp = DP4(vtx->position, plane)
+ */
+ brw_DP4(p, vec4(c->reg.dp0), deref_4f(vtx0, c->offset[VERT_RESULT_HPOS]), c->reg.plane_equation);
+
+ /* if (IS_NEGATIVE(dp1))
+ */
+ brw_set_conditionalmod(p, BRW_CONDITIONAL_L);
+ brw_DP4(p, vec4(c->reg.dp1), deref_4f(vtx1, c->offset[VERT_RESULT_HPOS]), c->reg.plane_equation);
+#else
+ #warning "disabled"
+#endif
+ is_negative = brw_IF(p, BRW_EXECUTE_1);
+ {
+ brw_ADD(p, c->reg.t, c->reg.dp1, negate(c->reg.dp0));
+ brw_math_invert(p, c->reg.t, c->reg.t);
+ brw_MUL(p, c->reg.t, c->reg.t, c->reg.dp1);
+
+ brw_CMP(p, vec1(brw_null_reg()), BRW_CONDITIONAL_G, c->reg.t, c->reg.t1 );
+ brw_MOV(p, c->reg.t1, c->reg.t);
+ brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+ }
+ is_negative = brw_ELSE(p, is_negative);
+ {
+ /* Coming back in. We know that both cannot be negative
+ * because the line would have been culled in that case.
+ */
+
+ /* If both are positive, do nothing */
+ brw_CMP(p, vec1(brw_null_reg()), BRW_CONDITIONAL_L, c->reg.dp0, brw_imm_f(0.0));
+ is_neg2 = brw_IF(p, BRW_EXECUTE_1);
+ {
+ brw_ADD(p, c->reg.t, c->reg.dp0, negate(c->reg.dp1));
+ brw_math_invert(p, c->reg.t, c->reg.t);
+ brw_MUL(p, c->reg.t, c->reg.t, c->reg.dp0);
+
+ brw_CMP(p, vec1(brw_null_reg()), BRW_CONDITIONAL_G, c->reg.t, c->reg.t0 );
+ brw_MOV(p, c->reg.t0, c->reg.t);
+ brw_set_predicate_control(p, BRW_PREDICATE_NONE);
+ }
+ brw_ENDIF(p, is_neg2);
+ }
+ brw_ENDIF(p, is_negative);
+ }
+ brw_ENDIF(p, plane_active);
+
+ /* plane_ptr++;
+ */
+ brw_ADD(p, get_addr_reg(plane_ptr), get_addr_reg(plane_ptr), brw_clip_plane_stride(c));
+
+ /* while (planemask>>=1) != 0
+ */
+ brw_set_conditionalmod(p, BRW_CONDITIONAL_NZ);
+ brw_SHR(p, c->reg.planemask, c->reg.planemask, brw_imm_ud(1));
+ }
+ brw_WHILE(p, plane_loop);
+
+ brw_ADD(p, c->reg.t, c->reg.t0, c->reg.t1);
+ brw_CMP(p, vec1(brw_null_reg()), BRW_CONDITIONAL_L, c->reg.t, brw_imm_f(1.0));
+ not_culled = brw_IF(p, BRW_EXECUTE_1);
+ {
+ brw_clip_interp_vertex(c, newvtx0, vtx0, vtx1, c->reg.t0, FALSE);
+ brw_clip_interp_vertex(c, newvtx1, vtx1, vtx0, c->reg.t1, FALSE);
+
+ brw_clip_emit_vue(c, newvtx0, 1, 0, (_3DPRIM_LINESTRIP << 2) | R02_PRIM_START);
+ brw_clip_emit_vue(c, newvtx1, 0, 1, (_3DPRIM_LINESTRIP << 2) | R02_PRIM_END);
+ }
+ brw_ENDIF(p, not_culled);
+ brw_clip_kill_thread(c);
+}
+
+
+
+void brw_emit_line_clip( struct brw_clip_compile *c )
+{
+ brw_clip_line_alloc_regs(c);
+
+ if (c->key.do_flat_shading)
+ brw_clip_copy_colors(c, 0, 1);
+
+ clip_and_emit_line(c);
+}
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