1 /*
2 * Copyright © 2009 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 * Eric Anholt <eric@anholt.net>
25 *
26 */
27
28 #include "brw_context.h"
29 #include "brw_state.h"
30 #include "brw_defines.h"
31 #include "brw_util.h"
32 #include "main/macros.h"
33 #include "main/fbobject.h"
34 #include "intel_batchbuffer.h"
35
36 /**
37 * Determine the appropriate attribute override value to store into the
38 * 3DSTATE_SF structure for a given fragment shader attribute. The attribute
39 * override value contains two pieces of information: the location of the
40 * attribute in the VUE (relative to urb_entry_read_offset, see below), and a
41 * flag indicating whether to "swizzle" the attribute based on the direction
42 * the triangle is facing.
43 *
44 * If an attribute is "swizzled", then the given VUE location is used for
45 * front-facing triangles, and the VUE location that immediately follows is
46 * used for back-facing triangles. We use this to implement the mapping from
47 * gl_FrontColor/gl_BackColor to gl_Color.
48 *
49 * urb_entry_read_offset is the offset into the VUE at which the SF unit is
50 * being instructed to begin reading attribute data. It can be set to a
51 * nonzero value to prevent the SF unit from wasting time reading elements of
52 * the VUE that are not needed by the fragment shader. It is measured in
53 * 256-bit increments.
54 */
55 uint32_t
get_attr_override(struct brw_vue_map * vue_map,int urb_entry_read_offset,int fs_attr,bool two_side_color,uint32_t * max_source_attr)56 get_attr_override(struct brw_vue_map *vue_map, int urb_entry_read_offset,
57 int fs_attr, bool two_side_color, uint32_t *max_source_attr)
58 {
59 int vs_attr = _mesa_frag_attrib_to_vert_result(fs_attr);
60 if (vs_attr < 0 || vs_attr == VERT_RESULT_HPOS) {
61 /* These attributes will be overwritten by the fragment shader's
62 * interpolation code (see emit_interp() in brw_wm_fp.c), so just let
63 * them reference the first available attribute.
64 */
65 return 0;
66 }
67
68 /* Find the VUE slot for this attribute. */
69 int slot = vue_map->vert_result_to_slot[vs_attr];
70
71 /* If there was only a back color written but not front, use back
72 * as the color instead of undefined
73 */
74 if (slot == -1 && vs_attr == VERT_RESULT_COL0)
75 slot = vue_map->vert_result_to_slot[VERT_RESULT_BFC0];
76 if (slot == -1 && vs_attr == VERT_RESULT_COL1)
77 slot = vue_map->vert_result_to_slot[VERT_RESULT_BFC1];
78
79 if (slot == -1) {
80 /* This attribute does not exist in the VUE--that means that the vertex
81 * shader did not write to it. Behavior is undefined in this case, so
82 * just reference the first available attribute.
83 */
84 return 0;
85 }
86
87 /* Compute the location of the attribute relative to urb_entry_read_offset.
88 * Each increment of urb_entry_read_offset represents a 256-bit value, so
89 * it counts for two 128-bit VUE slots.
90 */
91 int source_attr = slot - 2 * urb_entry_read_offset;
92 assert(source_attr >= 0 && source_attr < 32);
93
94 /* If we are doing two-sided color, and the VUE slot following this one
95 * represents a back-facing color, then we need to instruct the SF unit to
96 * do back-facing swizzling.
97 */
98 bool swizzling = two_side_color &&
99 ((vue_map->slot_to_vert_result[slot] == VERT_RESULT_COL0 &&
100 vue_map->slot_to_vert_result[slot+1] == VERT_RESULT_BFC0) ||
101 (vue_map->slot_to_vert_result[slot] == VERT_RESULT_COL1 &&
102 vue_map->slot_to_vert_result[slot+1] == VERT_RESULT_BFC1));
103
104 /* Update max_source_attr. If swizzling, the SF will read this slot + 1. */
105 if (*max_source_attr < source_attr + swizzling)
106 *max_source_attr = source_attr + swizzling;
107
108 if (swizzling) {
109 return source_attr |
110 (ATTRIBUTE_SWIZZLE_INPUTATTR_FACING << ATTRIBUTE_SWIZZLE_SHIFT);
111 }
112
113 return source_attr;
114 }
115
116 static void
upload_sf_state(struct brw_context * brw)117 upload_sf_state(struct brw_context *brw)
118 {
119 struct intel_context *intel = &brw->intel;
120 struct gl_context *ctx = &intel->ctx;
121 /* BRW_NEW_FRAGMENT_PROGRAM */
122 uint32_t num_outputs = _mesa_bitcount_64(brw->fragment_program->Base.InputsRead);
123 /* _NEW_LIGHT */
124 bool shade_model_flat = ctx->Light.ShadeModel == GL_FLAT;
125 uint32_t dw1, dw2, dw3, dw4, dw16, dw17;
126 int i;
127 /* _NEW_BUFFER */
128 bool render_to_fbo = _mesa_is_user_fbo(brw->intel.ctx.DrawBuffer);
129 bool multisampled_fbo = ctx->DrawBuffer->Visual.samples > 1;
130
131 int attr = 0, input_index = 0;
132 int urb_entry_read_offset = 1;
133 float point_size;
134 uint16_t attr_overrides[FRAG_ATTRIB_MAX];
135 uint32_t point_sprite_origin;
136
137 dw1 = GEN6_SF_SWIZZLE_ENABLE | num_outputs << GEN6_SF_NUM_OUTPUTS_SHIFT;
138
139 dw2 = GEN6_SF_STATISTICS_ENABLE |
140 GEN6_SF_VIEWPORT_TRANSFORM_ENABLE;
141
142 dw3 = 0;
143 dw4 = 0;
144 dw16 = 0;
145 dw17 = 0;
146
147 /* _NEW_POLYGON */
148 if ((ctx->Polygon.FrontFace == GL_CCW) ^ render_to_fbo)
149 dw2 |= GEN6_SF_WINDING_CCW;
150
151 if (ctx->Polygon.OffsetFill)
152 dw2 |= GEN6_SF_GLOBAL_DEPTH_OFFSET_SOLID;
153
154 if (ctx->Polygon.OffsetLine)
155 dw2 |= GEN6_SF_GLOBAL_DEPTH_OFFSET_WIREFRAME;
156
157 if (ctx->Polygon.OffsetPoint)
158 dw2 |= GEN6_SF_GLOBAL_DEPTH_OFFSET_POINT;
159
160 switch (ctx->Polygon.FrontMode) {
161 case GL_FILL:
162 dw2 |= GEN6_SF_FRONT_SOLID;
163 break;
164
165 case GL_LINE:
166 dw2 |= GEN6_SF_FRONT_WIREFRAME;
167 break;
168
169 case GL_POINT:
170 dw2 |= GEN6_SF_FRONT_POINT;
171 break;
172
173 default:
174 assert(0);
175 break;
176 }
177
178 switch (ctx->Polygon.BackMode) {
179 case GL_FILL:
180 dw2 |= GEN6_SF_BACK_SOLID;
181 break;
182
183 case GL_LINE:
184 dw2 |= GEN6_SF_BACK_WIREFRAME;
185 break;
186
187 case GL_POINT:
188 dw2 |= GEN6_SF_BACK_POINT;
189 break;
190
191 default:
192 assert(0);
193 break;
194 }
195
196 /* _NEW_SCISSOR */
197 if (ctx->Scissor.Enabled)
198 dw3 |= GEN6_SF_SCISSOR_ENABLE;
199
200 /* _NEW_POLYGON */
201 if (ctx->Polygon.CullFlag) {
202 switch (ctx->Polygon.CullFaceMode) {
203 case GL_FRONT:
204 dw3 |= GEN6_SF_CULL_FRONT;
205 break;
206 case GL_BACK:
207 dw3 |= GEN6_SF_CULL_BACK;
208 break;
209 case GL_FRONT_AND_BACK:
210 dw3 |= GEN6_SF_CULL_BOTH;
211 break;
212 default:
213 assert(0);
214 break;
215 }
216 } else {
217 dw3 |= GEN6_SF_CULL_NONE;
218 }
219
220 /* _NEW_LINE */
221 {
222 uint32_t line_width_u3_7 = U_FIXED(CLAMP(ctx->Line.Width, 0.0, 7.99), 7);
223 /* TODO: line width of 0 is not allowed when MSAA enabled */
224 if (line_width_u3_7 == 0)
225 line_width_u3_7 = 1;
226 dw3 |= line_width_u3_7 << GEN6_SF_LINE_WIDTH_SHIFT;
227 }
228 if (ctx->Line.SmoothFlag) {
229 dw3 |= GEN6_SF_LINE_AA_ENABLE;
230 dw3 |= GEN6_SF_LINE_AA_MODE_TRUE;
231 dw3 |= GEN6_SF_LINE_END_CAP_WIDTH_1_0;
232 }
233 /* _NEW_MULTISAMPLE */
234 if (multisampled_fbo && ctx->Multisample.Enabled)
235 dw3 |= GEN6_SF_MSRAST_ON_PATTERN;
236
237 /* _NEW_PROGRAM | _NEW_POINT */
238 if (!(ctx->VertexProgram.PointSizeEnabled ||
239 ctx->Point._Attenuated))
240 dw4 |= GEN6_SF_USE_STATE_POINT_WIDTH;
241
242 /* Clamp to ARB_point_parameters user limits */
243 point_size = CLAMP(ctx->Point.Size, ctx->Point.MinSize, ctx->Point.MaxSize);
244
245 /* Clamp to the hardware limits and convert to fixed point */
246 dw4 |= U_FIXED(CLAMP(point_size, 0.125, 255.875), 3);
247
248 /*
249 * Window coordinates in an FBO are inverted, which means point
250 * sprite origin must be inverted, too.
251 */
252 if ((ctx->Point.SpriteOrigin == GL_LOWER_LEFT) != render_to_fbo) {
253 point_sprite_origin = GEN6_SF_POINT_SPRITE_LOWERLEFT;
254 } else {
255 point_sprite_origin = GEN6_SF_POINT_SPRITE_UPPERLEFT;
256 }
257 dw1 |= point_sprite_origin;
258
259 /* _NEW_LIGHT */
260 if (ctx->Light.ProvokingVertex != GL_FIRST_VERTEX_CONVENTION) {
261 dw4 |=
262 (2 << GEN6_SF_TRI_PROVOKE_SHIFT) |
263 (2 << GEN6_SF_TRIFAN_PROVOKE_SHIFT) |
264 (1 << GEN6_SF_LINE_PROVOKE_SHIFT);
265 } else {
266 dw4 |=
267 (1 << GEN6_SF_TRIFAN_PROVOKE_SHIFT);
268 }
269
270 /* Create the mapping from the FS inputs we produce to the VS outputs
271 * they source from.
272 */
273 uint32_t max_source_attr = 0;
274 for (; attr < FRAG_ATTRIB_MAX; attr++) {
275 enum glsl_interp_qualifier interp_qualifier =
276 brw->fragment_program->InterpQualifier[attr];
277 bool is_gl_Color = attr == FRAG_ATTRIB_COL0 || attr == FRAG_ATTRIB_COL1;
278
279 if (!(brw->fragment_program->Base.InputsRead & BITFIELD64_BIT(attr)))
280 continue;
281
282 /* _NEW_POINT */
283 if (ctx->Point.PointSprite &&
284 (attr >= FRAG_ATTRIB_TEX0 && attr <= FRAG_ATTRIB_TEX7) &&
285 ctx->Point.CoordReplace[attr - FRAG_ATTRIB_TEX0]) {
286 dw16 |= (1 << input_index);
287 }
288
289 if (attr == FRAG_ATTRIB_PNTC)
290 dw16 |= (1 << input_index);
291
292 /* flat shading */
293 if (interp_qualifier == INTERP_QUALIFIER_FLAT ||
294 (shade_model_flat && is_gl_Color &&
295 interp_qualifier == INTERP_QUALIFIER_NONE))
296 dw17 |= (1 << input_index);
297
298 /* The hardware can only do the overrides on 16 overrides at a
299 * time, and the other up to 16 have to be lined up so that the
300 * input index = the output index. We'll need to do some
301 * tweaking to make sure that's the case.
302 */
303 assert(input_index < 16 || attr == input_index);
304
305 /* CACHE_NEW_VS_PROG | _NEW_LIGHT | _NEW_PROGRAM */
306 attr_overrides[input_index++] =
307 get_attr_override(&brw->vs.prog_data->vue_map,
308 urb_entry_read_offset, attr,
309 ctx->VertexProgram._TwoSideEnabled,
310 &max_source_attr);
311 }
312
313 for (; input_index < FRAG_ATTRIB_MAX; input_index++)
314 attr_overrides[input_index] = 0;
315
316 /* From the Sandy Bridge PRM, Volume 2, Part 1, documentation for
317 * 3DSTATE_SF DWord 1 bits 15:11, "Vertex URB Entry Read Length":
318 *
319 * "This field should be set to the minimum length required to read the
320 * maximum source attribute. The maximum source attribute is indicated
321 * by the maximum value of the enabled Attribute # Source Attribute if
322 * Attribute Swizzle Enable is set, Number of Output Attributes-1 if
323 * enable is not set.
324 * read_length = ceiling((max_source_attr + 1) / 2)
325 *
326 * [errata] Corruption/Hang possible if length programmed larger than
327 * recommended"
328 */
329 uint32_t urb_entry_read_length = ALIGN(max_source_attr + 1, 2) / 2;
330 dw1 |= urb_entry_read_length << GEN6_SF_URB_ENTRY_READ_LENGTH_SHIFT |
331 urb_entry_read_offset << GEN6_SF_URB_ENTRY_READ_OFFSET_SHIFT;
332
333 BEGIN_BATCH(20);
334 OUT_BATCH(_3DSTATE_SF << 16 | (20 - 2));
335 OUT_BATCH(dw1);
336 OUT_BATCH(dw2);
337 OUT_BATCH(dw3);
338 OUT_BATCH(dw4);
339 OUT_BATCH_F(ctx->Polygon.OffsetUnits * 2); /* constant. copied from gen4 */
340 OUT_BATCH_F(ctx->Polygon.OffsetFactor); /* scale */
341 OUT_BATCH_F(0.0); /* XXX: global depth offset clamp */
342 for (i = 0; i < 8; i++) {
343 OUT_BATCH(attr_overrides[i * 2] | attr_overrides[i * 2 + 1] << 16);
344 }
345 OUT_BATCH(dw16); /* point sprite texcoord bitmask */
346 OUT_BATCH(dw17); /* constant interp bitmask */
347 OUT_BATCH(0); /* wrapshortest enables 0-7 */
348 OUT_BATCH(0); /* wrapshortest enables 8-15 */
349 ADVANCE_BATCH();
350 }
351
352 const struct brw_tracked_state gen6_sf_state = {
353 .dirty = {
354 .mesa = (_NEW_LIGHT |
355 _NEW_PROGRAM |
356 _NEW_POLYGON |
357 _NEW_LINE |
358 _NEW_SCISSOR |
359 _NEW_BUFFERS |
360 _NEW_POINT |
361 _NEW_MULTISAMPLE),
362 .brw = (BRW_NEW_CONTEXT |
363 BRW_NEW_FRAGMENT_PROGRAM),
364 .cache = CACHE_NEW_VS_PROG
365 },
366 .emit = upload_sf_state,
367 };
368