diff options
Diffstat (limited to 'src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp')
-rw-r--r-- | src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp index 620f652..f81ee4e 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp @@ -202,8 +202,68 @@ vec4_vs_visitor::emit_urb_write_opcode(bool complete) void +vec4_vs_visitor::emit_clip_distances(dst_reg reg, int offset) +{ + /* From the GLSL 1.30 spec, section 7.1 (Vertex Shader Special Variables): + * + * "If a linked set of shaders forming the vertex stage contains no + * static write to gl_ClipVertex or gl_ClipDistance, but the + * application has requested clipping against user clip planes through + * the API, then the coordinate written to gl_Position is used for + * comparison against the user clip planes." + * + * This function is only called if the shader didn't write to + * gl_ClipDistance. Accordingly, we use gl_ClipVertex to perform clipping + * if the user wrote to it; otherwise we use gl_Position. + */ + gl_varying_slot clip_vertex = VARYING_SLOT_CLIP_VERTEX; + if (!(prog_data->vue_map.slots_valid & VARYING_BIT_CLIP_VERTEX)) { + clip_vertex = VARYING_SLOT_POS; + } + + for (int i = 0; i + offset < key->base.nr_userclip_plane_consts && i < 4; + ++i) { + reg.writemask = 1 << i; + emit(DP4(reg, + src_reg(output_reg[clip_vertex]), + src_reg(this->userplane[i + offset]))); + } +} + + +void +vec4_vs_visitor::setup_uniform_clipplane_values() +{ + for (int i = 0; i < key->base.nr_userclip_plane_consts; ++i) { + assert(this->uniforms < uniform_array_size); + this->uniform_vector_size[this->uniforms] = 4; + this->userplane[i] = dst_reg(UNIFORM, this->uniforms); + this->userplane[i].type = BRW_REGISTER_TYPE_F; + for (int j = 0; j < 4; ++j) { + stage_prog_data->param[this->uniforms * 4 + j] = + (gl_constant_value *) &clip_planes[i][j]; + } + ++this->uniforms; + } +} + + +void vec4_vs_visitor::emit_thread_end() { + setup_uniform_clipplane_values(); + + /* Lower legacy ff and ClipVertex clipping to clip distances */ + if (key->base.nr_userclip_plane_consts > 0) { + current_annotation = "user clip distances"; + + output_reg[VARYING_SLOT_CLIP_DIST0] = dst_reg(this, glsl_type::vec4_type); + output_reg[VARYING_SLOT_CLIP_DIST1] = dst_reg(this, glsl_type::vec4_type); + + emit_clip_distances(output_reg[VARYING_SLOT_CLIP_DIST0], 0); + emit_clip_distances(output_reg[VARYING_SLOT_CLIP_DIST1], 4); + } + /* For VS, we always end the thread by emitting a single vertex. * emit_urb_write_opcode() will take care of setting the eot flag on the * SEND instruction. @@ -218,6 +278,7 @@ vec4_vs_visitor::vec4_vs_visitor(const struct brw_compiler *compiler, struct brw_vs_prog_data *vs_prog_data, struct gl_vertex_program *vp, struct gl_shader_program *prog, + gl_clip_plane *clip_planes, void *mem_ctx, int shader_time_index, bool use_legacy_snorm_formula) @@ -229,6 +290,7 @@ vec4_vs_visitor::vec4_vs_visitor(const struct brw_compiler *compiler, key(key), vs_prog_data(vs_prog_data), vp(vp), + clip_planes(clip_planes), use_legacy_snorm_formula(use_legacy_snorm_formula) { } |