1/*
2 * Copyright © 2017 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
24#include "anv_nir.h"
25#include "anv_private.h"
26#include "nir/nir.h"
27#include "nir/nir_builder.h"
28#include "nir/nir_vulkan.h"
29
30struct ycbcr_state {
31   nir_builder *builder;
32   nir_ssa_def *image_size;
33   nir_tex_instr *origin_tex;
34   nir_deref_instr *tex_deref;
35   struct anv_ycbcr_conversion *conversion;
36};
37
38/* TODO: we should probably replace this with a push constant/uniform. */
39static nir_ssa_def *
40get_texture_size(struct ycbcr_state *state, nir_deref_instr *texture)
41{
42   if (state->image_size)
43      return state->image_size;
44
45   nir_builder *b = state->builder;
46   const struct glsl_type *type = texture->type;
47   nir_tex_instr *tex = nir_tex_instr_create(b->shader, 1);
48
49   tex->op = nir_texop_txs;
50   tex->sampler_dim = glsl_get_sampler_dim(type);
51   tex->is_array = glsl_sampler_type_is_array(type);
52   tex->is_shadow = glsl_sampler_type_is_shadow(type);
53   tex->dest_type = nir_type_int32;
54
55   tex->src[0].src_type = nir_tex_src_texture_deref;
56   tex->src[0].src = nir_src_for_ssa(&texture->dest.ssa);
57
58   nir_ssa_dest_init(&tex->instr, &tex->dest,
59                     nir_tex_instr_dest_size(tex), 32, NULL);
60   nir_builder_instr_insert(b, &tex->instr);
61
62   state->image_size = nir_i2f32(b, &tex->dest.ssa);
63
64   return state->image_size;
65}
66
67static nir_ssa_def *
68implicit_downsampled_coord(nir_builder *b,
69                           nir_ssa_def *value,
70                           nir_ssa_def *max_value,
71                           int div_scale)
72{
73   return nir_fadd(b,
74                   value,
75                   nir_fdiv(b,
76                            nir_imm_float(b, 1.0f),
77                            nir_fmul(b,
78                                     nir_imm_float(b, div_scale),
79                                     max_value)));
80}
81
82static nir_ssa_def *
83implicit_downsampled_coords(struct ycbcr_state *state,
84                            nir_ssa_def *old_coords,
85                            const struct anv_format_plane *plane_format)
86{
87   nir_builder *b = state->builder;
88   struct anv_ycbcr_conversion *conversion = state->conversion;
89   nir_ssa_def *image_size = get_texture_size(state, state->tex_deref);
90   nir_ssa_def *comp[4] = { NULL, };
91   int c;
92
93   for (c = 0; c < ARRAY_SIZE(conversion->chroma_offsets); c++) {
94      if (plane_format->denominator_scales[c] > 1 &&
95          conversion->chroma_offsets[c] == VK_CHROMA_LOCATION_COSITED_EVEN) {
96         comp[c] = implicit_downsampled_coord(b,
97                                              nir_channel(b, old_coords, c),
98                                              nir_channel(b, image_size, c),
99                                              plane_format->denominator_scales[c]);
100      } else {
101         comp[c] = nir_channel(b, old_coords, c);
102      }
103   }
104
105   /* Leave other coordinates untouched */
106   for (; c < old_coords->num_components; c++)
107      comp[c] = nir_channel(b, old_coords, c);
108
109   return nir_vec(b, comp, old_coords->num_components);
110}
111
112static nir_ssa_def *
113create_plane_tex_instr_implicit(struct ycbcr_state *state,
114                                uint32_t plane)
115{
116   nir_builder *b = state->builder;
117   struct anv_ycbcr_conversion *conversion = state->conversion;
118   const struct anv_format_plane *plane_format =
119      &conversion->format->planes[plane];
120   nir_tex_instr *old_tex = state->origin_tex;
121   nir_tex_instr *tex = nir_tex_instr_create(b->shader, old_tex->num_srcs + 1);
122
123   for (uint32_t i = 0; i < old_tex->num_srcs; i++) {
124      tex->src[i].src_type = old_tex->src[i].src_type;
125
126      switch (old_tex->src[i].src_type) {
127      case nir_tex_src_coord:
128         if (plane_format->has_chroma && conversion->chroma_reconstruction) {
129            assert(old_tex->src[i].src.is_ssa);
130            tex->src[i].src =
131               nir_src_for_ssa(implicit_downsampled_coords(state,
132                                                           old_tex->src[i].src.ssa,
133                                                           plane_format));
134            break;
135         }
136         FALLTHROUGH;
137      default:
138         nir_src_copy(&tex->src[i].src, &old_tex->src[i].src);
139         break;
140      }
141   }
142   tex->src[tex->num_srcs - 1].src = nir_src_for_ssa(nir_imm_int(b, plane));
143   tex->src[tex->num_srcs - 1].src_type = nir_tex_src_plane;
144
145   tex->sampler_dim = old_tex->sampler_dim;
146   tex->dest_type = old_tex->dest_type;
147
148   tex->op = old_tex->op;
149   tex->coord_components = old_tex->coord_components;
150   tex->is_new_style_shadow = old_tex->is_new_style_shadow;
151   tex->component = old_tex->component;
152
153   tex->texture_index = old_tex->texture_index;
154   tex->sampler_index = old_tex->sampler_index;
155   tex->is_array = old_tex->is_array;
156
157   nir_ssa_dest_init(&tex->instr, &tex->dest,
158                     old_tex->dest.ssa.num_components,
159                     nir_dest_bit_size(old_tex->dest), NULL);
160   nir_builder_instr_insert(b, &tex->instr);
161
162   return &tex->dest.ssa;
163}
164
165static unsigned
166channel_to_component(enum isl_channel_select channel)
167{
168   switch (channel) {
169   case ISL_CHANNEL_SELECT_RED:
170      return 0;
171   case ISL_CHANNEL_SELECT_GREEN:
172      return 1;
173   case ISL_CHANNEL_SELECT_BLUE:
174      return 2;
175   case ISL_CHANNEL_SELECT_ALPHA:
176      return 3;
177   default:
178      unreachable("invalid channel");
179      return 0;
180   }
181}
182
183static enum isl_channel_select
184swizzle_channel(struct isl_swizzle swizzle, unsigned channel)
185{
186   switch (channel) {
187   case 0:
188      return swizzle.r;
189   case 1:
190      return swizzle.g;
191   case 2:
192      return swizzle.b;
193   case 3:
194      return swizzle.a;
195   default:
196      unreachable("invalid channel");
197      return 0;
198   }
199}
200
201static bool
202anv_nir_lower_ycbcr_textures_instr(nir_builder *builder,
203                                   nir_instr *instr,
204                                   void *cb_data)
205{
206   const struct anv_pipeline_layout *layout = cb_data;
207
208   if (instr->type != nir_instr_type_tex)
209      return false;
210
211   nir_tex_instr *tex = nir_instr_as_tex(instr);
212
213   int deref_src_idx = nir_tex_instr_src_index(tex, nir_tex_src_texture_deref);
214   assert(deref_src_idx >= 0);
215   nir_deref_instr *deref = nir_src_as_deref(tex->src[deref_src_idx].src);
216
217   nir_variable *var = nir_deref_instr_get_variable(deref);
218   const struct anv_descriptor_set_layout *set_layout =
219      layout->set[var->data.descriptor_set].layout;
220   const struct anv_descriptor_set_binding_layout *binding =
221      &set_layout->binding[var->data.binding];
222
223   /* For the following instructions, we don't apply any change and let the
224    * instruction apply to the first plane.
225    */
226   if (tex->op == nir_texop_txs ||
227       tex->op == nir_texop_query_levels ||
228       tex->op == nir_texop_lod)
229      return false;
230
231   if (binding->immutable_samplers == NULL)
232      return false;
233
234   assert(tex->texture_index == 0);
235   unsigned array_index = 0;
236   if (deref->deref_type != nir_deref_type_var) {
237      assert(deref->deref_type == nir_deref_type_array);
238      if (!nir_src_is_const(deref->arr.index))
239         return false;
240      array_index = nir_src_as_uint(deref->arr.index);
241      array_index = MIN2(array_index, binding->array_size - 1);
242   }
243   const struct anv_sampler *sampler = binding->immutable_samplers[array_index];
244
245   if (sampler->conversion == NULL)
246      return false;
247
248   struct ycbcr_state state = {
249      .builder = builder,
250      .origin_tex = tex,
251      .tex_deref = deref,
252      .conversion = sampler->conversion,
253   };
254
255   builder->cursor = nir_before_instr(&tex->instr);
256
257   const struct anv_format *format = state.conversion->format;
258   const struct isl_format_layout *y_isl_layout = NULL;
259   for (uint32_t p = 0; p < format->n_planes; p++) {
260      if (!format->planes[p].has_chroma)
261         y_isl_layout = isl_format_get_layout(format->planes[p].isl_format);
262   }
263   assert(y_isl_layout != NULL);
264   uint8_t y_bpc = y_isl_layout->channels_array[0].bits;
265
266   /* |ycbcr_comp| holds components in the order : Cr-Y-Cb */
267   nir_ssa_def *zero = nir_imm_float(builder, 0.0f);
268   nir_ssa_def *one = nir_imm_float(builder, 1.0f);
269   /* Use extra 2 channels for following swizzle */
270   nir_ssa_def *ycbcr_comp[5] = { zero, zero, zero, one, zero };
271
272   uint8_t ycbcr_bpcs[5];
273   memset(ycbcr_bpcs, y_bpc, sizeof(ycbcr_bpcs));
274
275   /* Go through all the planes and gather the samples into a |ycbcr_comp|
276    * while applying a swizzle required by the spec:
277    *
278    *    R, G, B should respectively map to Cr, Y, Cb
279    */
280   for (uint32_t p = 0; p < format->n_planes; p++) {
281      const struct anv_format_plane *plane_format = &format->planes[p];
282      nir_ssa_def *plane_sample = create_plane_tex_instr_implicit(&state, p);
283
284      for (uint32_t pc = 0; pc < 4; pc++) {
285         enum isl_channel_select ycbcr_swizzle =
286            swizzle_channel(plane_format->ycbcr_swizzle, pc);
287         if (ycbcr_swizzle == ISL_CHANNEL_SELECT_ZERO)
288            continue;
289
290         unsigned ycbcr_component = channel_to_component(ycbcr_swizzle);
291         ycbcr_comp[ycbcr_component] = nir_channel(builder, plane_sample, pc);
292
293         /* Also compute the number of bits for each component. */
294         const struct isl_format_layout *isl_layout =
295            isl_format_get_layout(plane_format->isl_format);
296         ycbcr_bpcs[ycbcr_component] = isl_layout->channels_array[pc].bits;
297      }
298   }
299
300   /* Now remaps components to the order specified by the conversion. */
301   nir_ssa_def *swizzled_comp[4] = { NULL, };
302   uint32_t swizzled_bpcs[4] = { 0, };
303
304   for (uint32_t i = 0; i < ARRAY_SIZE(state.conversion->mapping); i++) {
305      /* Maps to components in |ycbcr_comp| */
306      static const uint32_t swizzle_mapping[] = {
307         [VK_COMPONENT_SWIZZLE_ZERO] = 4,
308         [VK_COMPONENT_SWIZZLE_ONE]  = 3,
309         [VK_COMPONENT_SWIZZLE_R]    = 0,
310         [VK_COMPONENT_SWIZZLE_G]    = 1,
311         [VK_COMPONENT_SWIZZLE_B]    = 2,
312         [VK_COMPONENT_SWIZZLE_A]    = 3,
313      };
314      const VkComponentSwizzle m = state.conversion->mapping[i];
315
316      if (m == VK_COMPONENT_SWIZZLE_IDENTITY) {
317         swizzled_comp[i] = ycbcr_comp[i];
318         swizzled_bpcs[i] = ycbcr_bpcs[i];
319      } else {
320         swizzled_comp[i] = ycbcr_comp[swizzle_mapping[m]];
321         swizzled_bpcs[i] = ycbcr_bpcs[swizzle_mapping[m]];
322      }
323   }
324
325   nir_ssa_def *result = nir_vec(builder, swizzled_comp, 4);
326   if (state.conversion->ycbcr_model != VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY) {
327      result = nir_convert_ycbcr_to_rgb(builder,
328                                        state.conversion->ycbcr_model,
329                                        state.conversion->ycbcr_range,
330                                        result,
331                                        swizzled_bpcs);
332   }
333
334   nir_ssa_def_rewrite_uses(&tex->dest.ssa, result);
335   nir_instr_remove(&tex->instr);
336
337   return true;
338}
339
340bool
341anv_nir_lower_ycbcr_textures(nir_shader *shader,
342                             const struct anv_pipeline_layout *layout)
343{
344   return nir_shader_instructions_pass(shader,
345                                       anv_nir_lower_ycbcr_textures_instr,
346                                       nir_metadata_block_index |
347                                       nir_metadata_dominance,
348                                       (void *)layout);
349}
350