/* Interpolate between two vertices and put the result into a0.0. * Increment a0.0 accordingly. */ void brw_clip_interp_vertex( struct brw_clip_compile *c, struct brw_indirect dest_ptr, struct brw_indirect v0_ptr, /* from */ struct brw_indirect v1_ptr, /* to */ struct brw_reg t0, GLboolean force_edgeflag) { struct brw_compile *p = &c->func; struct brw_reg tmp = get_tmp(c); GLuint i; /* Just copy the vertex header: */ brw_copy_indirect_to_indirect(p, dest_ptr, v0_ptr, 1); /* Iterate over each attribute (could be done in pairs?) */ for (i = 0; i < c->nr_attrs; i++) { GLuint delta = i*16 + 32; if (delta == c->offset[VERT_RESULT_EDGE]) { if (force_edgeflag) brw_MOV(p, deref_4f(dest_ptr, delta), brw_imm_f(1)); else brw_MOV(p, deref_4f(dest_ptr, delta), deref_4f(v0_ptr, delta)); } else { /* Interpolate: * * New = attr0 + t*attr1 - t*attr0 */ brw_MUL(p, vec4(brw_null_reg()), deref_4f(v1_ptr, delta), t0); brw_MAC(p, tmp, negate(deref_4f(v0_ptr, delta)), t0); brw_ADD(p, deref_4f(dest_ptr, delta), deref_4f(v0_ptr, delta), tmp); } } if (i & 1) { GLuint delta = i*16 + 32; brw_MOV(p, deref_4f(dest_ptr, delta), brw_imm_f(0)); } release_tmp(c, tmp); /* Recreate the projected (NDC) coordinate in the new vertex * header: */ brw_clip_project_vertex(c, dest_ptr ); }
/* Interpolate between two vertices and put the result into a0.0. * Increment a0.0 accordingly. * * Beware that dest_ptr can be equal to v0_ptr! */ void brw_clip_interp_vertex( struct brw_clip_compile *c, struct brw_indirect dest_ptr, struct brw_indirect v0_ptr, /* from */ struct brw_indirect v1_ptr, /* to */ struct brw_reg t0, bool force_edgeflag) { struct brw_codegen *p = &c->func; struct brw_reg t_nopersp, v0_ndc_copy; GLuint slot; /* Just copy the vertex header: */ /* * After CLIP stage, only first 256 bits of the VUE are read * back on Ironlake, so needn't change it */ brw_copy_indirect_to_indirect(p, dest_ptr, v0_ptr, 1); /* First handle the 3D and NDC interpolation, in case we * need noperspective interpolation. Doing it early has no * performance impact in any case. */ /* Take a copy of the v0 NDC coordinates, in case dest == v0. */ if (c->has_noperspective_shading) { GLuint offset = brw_varying_to_offset(&c->vue_map, BRW_VARYING_SLOT_NDC); v0_ndc_copy = get_tmp(c); brw_MOV(p, v0_ndc_copy, deref_4f(v0_ptr, offset)); } /* Compute the new 3D position * * dest_hpos = v0_hpos * (1 - t0) + v1_hpos * t0 */ { GLuint delta = brw_varying_to_offset(&c->vue_map, VARYING_SLOT_POS); struct brw_reg tmp = get_tmp(c); brw_MUL(p, vec4(brw_null_reg()), deref_4f(v1_ptr, delta), t0); brw_MAC(p, tmp, negate(deref_4f(v0_ptr, delta)), t0); brw_ADD(p, deref_4f(dest_ptr, delta), deref_4f(v0_ptr, delta), tmp); release_tmp(c, tmp); } /* Recreate the projected (NDC) coordinate in the new vertex header */ brw_clip_project_vertex(c, dest_ptr); /* If we have noperspective attributes, * we need to compute the screen-space t */ if (c->has_noperspective_shading) { GLuint delta = brw_varying_to_offset(&c->vue_map, BRW_VARYING_SLOT_NDC); struct brw_reg tmp = get_tmp(c); t_nopersp = get_tmp(c); /* t_nopersp = vec4(v1.xy, dest.xy) */ brw_MOV(p, t_nopersp, deref_4f(v1_ptr, delta)); brw_MOV(p, tmp, deref_4f(dest_ptr, delta)); brw_set_default_access_mode(p, BRW_ALIGN_16); brw_MOV(p, brw_writemask(t_nopersp, WRITEMASK_ZW), brw_swizzle(tmp, 0, 1, 0, 1)); /* t_nopersp = vec4(v1.xy, dest.xy) - v0.xyxy */ brw_ADD(p, t_nopersp, t_nopersp, negate(brw_swizzle(v0_ndc_copy, 0, 1, 0, 1))); /* Add the absolute values of the X and Y deltas so that if * the points aren't in the same place on the screen we get * nonzero values to divide. * * After that, we have vert1 - vert0 in t_nopersp.x and * vertnew - vert0 in t_nopersp.y * * t_nopersp = vec2(|v1.x -v0.x| + |v1.y -v0.y|, * |dest.x-v0.x| + |dest.y-v0.y|) */ brw_ADD(p, brw_writemask(t_nopersp, WRITEMASK_XY), brw_abs(brw_swizzle(t_nopersp, 0, 2, 0, 0)), brw_abs(brw_swizzle(t_nopersp, 1, 3, 0, 0))); brw_set_default_access_mode(p, BRW_ALIGN_1); /* If the points are in the same place, just substitute a * value to avoid divide-by-zero */ brw_CMP(p, vec1(brw_null_reg()), BRW_CONDITIONAL_EQ, vec1(t_nopersp), brw_imm_f(0)); brw_IF(p, BRW_EXECUTE_1); brw_MOV(p, t_nopersp, brw_imm_vf4(brw_float_to_vf(1.0), brw_float_to_vf(0.0), brw_float_to_vf(0.0), brw_float_to_vf(0.0))); brw_ENDIF(p); /* Now compute t_nopersp = t_nopersp.y/t_nopersp.x and broadcast it. */ brw_math_invert(p, get_element(t_nopersp, 0), get_element(t_nopersp, 0)); brw_MUL(p, vec1(t_nopersp), vec1(t_nopersp), vec1(suboffset(t_nopersp, 1))); brw_set_default_access_mode(p, BRW_ALIGN_16); brw_MOV(p, t_nopersp, brw_swizzle(t_nopersp, 0, 0, 0, 0)); brw_set_default_access_mode(p, BRW_ALIGN_1); release_tmp(c, tmp); release_tmp(c, v0_ndc_copy); } /* Now we can iterate over each attribute * (could be done in pairs?) */ for (slot = 0; slot < c->vue_map.num_slots; slot++) { int varying = c->vue_map.slot_to_varying[slot]; GLuint delta = brw_vue_slot_to_offset(slot); /* HPOS, NDC already handled above */ if (varying == VARYING_SLOT_POS || varying == BRW_VARYING_SLOT_NDC) continue; if (varying == VARYING_SLOT_EDGE) { if (force_edgeflag) brw_MOV(p, deref_4f(dest_ptr, delta), brw_imm_f(1)); else brw_MOV(p, deref_4f(dest_ptr, delta), deref_4f(v0_ptr, delta)); } else if (varying == VARYING_SLOT_PSIZ) { /* PSIZ doesn't need interpolation because it isn't used by the * fragment shader. */ } else if (varying < VARYING_SLOT_MAX) { /* This is a true vertex result (and not a special value for the VUE * header), so interpolate: * * New = attr0 + t*attr1 - t*attr0 * * Unless the attribute is flat shaded -- in which case just copy * from one of the sources (doesn't matter which; already copied from pv) */ GLuint interp = c->key.interpolation_mode.mode[slot]; if (interp != INTERP_QUALIFIER_FLAT) { struct brw_reg tmp = get_tmp(c); struct brw_reg t = interp == INTERP_QUALIFIER_NOPERSPECTIVE ? t_nopersp : t0; brw_MUL(p, vec4(brw_null_reg()), deref_4f(v1_ptr, delta), t); brw_MAC(p, tmp, negate(deref_4f(v0_ptr, delta)), t); brw_ADD(p, deref_4f(dest_ptr, delta), deref_4f(v0_ptr, delta), tmp); release_tmp(c, tmp); } else { brw_MOV(p, deref_4f(dest_ptr, delta), deref_4f(v0_ptr, delta)); } } } if (c->vue_map.num_slots % 2) { GLuint delta = brw_vue_slot_to_offset(c->vue_map.num_slots); brw_MOV(p, deref_4f(dest_ptr, delta), brw_imm_f(0)); } if (c->has_noperspective_shading) release_tmp(c, t_nopersp); }
/* Interpolate between two vertices and put the result into a0.0. * Increment a0.0 accordingly. */ void brw_clip_interp_vertex( struct brw_clip_compile *c, struct brw_indirect dest_ptr, struct brw_indirect v0_ptr, /* from */ struct brw_indirect v1_ptr, /* to */ struct brw_reg t0, bool force_edgeflag) { struct brw_compile *p = &c->func; struct brw_reg tmp = get_tmp(c); GLuint slot; /* Just copy the vertex header: */ /* * After CLIP stage, only first 256 bits of the VUE are read * back on Ironlake, so needn't change it */ brw_copy_indirect_to_indirect(p, dest_ptr, v0_ptr, 1); /* Iterate over each attribute (could be done in pairs?) */ for (slot = 0; slot < c->vue_map.num_slots; slot++) { int varying = c->vue_map.slot_to_varying[slot]; GLuint delta = brw_vue_slot_to_offset(slot); if (varying == VARYING_SLOT_EDGE) { if (force_edgeflag) brw_MOV(p, deref_4f(dest_ptr, delta), brw_imm_f(1)); else brw_MOV(p, deref_4f(dest_ptr, delta), deref_4f(v0_ptr, delta)); } else if (varying == VARYING_SLOT_PSIZ || varying == VARYING_SLOT_CLIP_DIST0 || varying == VARYING_SLOT_CLIP_DIST1) { /* PSIZ doesn't need interpolation because it isn't used by the * fragment shader. CLIP_DIST0 and CLIP_DIST1 don't need * intepolation because on pre-GEN6, these are just placeholder VUE * slots that don't perform any action. */ } else if (varying < VARYING_SLOT_MAX) { /* This is a true vertex result (and not a special value for the VUE * header), so interpolate: * * New = attr0 + t*attr1 - t*attr0 */ brw_MUL(p, vec4(brw_null_reg()), deref_4f(v1_ptr, delta), t0); brw_MAC(p, tmp, negate(deref_4f(v0_ptr, delta)), t0); brw_ADD(p, deref_4f(dest_ptr, delta), deref_4f(v0_ptr, delta), tmp); } } if (c->vue_map.num_slots % 2) { GLuint delta = brw_vue_slot_to_offset(c->vue_map.num_slots); brw_MOV(p, deref_4f(dest_ptr, delta), brw_imm_f(0)); } release_tmp(c, tmp); /* Recreate the projected (NDC) coordinate in the new vertex * header: */ brw_clip_project_vertex(c, dest_ptr ); }