| /* |
| * Copyright © 2015 Red Hat |
| * |
| * 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 AUTHORS OR COPYRIGHT HOLDERS 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. |
| */ |
| |
| #include "nir.h" |
| #include "nir_builder.h" |
| |
| /* Lower glBitmap(). |
| * |
| * This is based on the logic in st_get_bitmap_shader() in TGSI compiler. |
| * From st_cb_bitmap.c: |
| * |
| * glBitmaps are drawn as textured quads. The user's bitmap pattern |
| * is stored in a texture image. An alpha8 texture format is used. |
| * The fragment shader samples a bit (texel) from the texture, then |
| * discards the fragment if the bit is off. |
| * |
| * Note that we actually store the inverse image of the bitmap to |
| * simplify the fragment program. An "on" bit gets stored as texel=0x0 |
| * and an "off" bit is stored as texel=0xff. Then we kill the |
| * fragment if the negated texel value is less than zero. |
| * |
| * Note that the texture format will be, according to what driver supports, |
| * in order of preference (with swizzle): |
| * |
| * I8_UNORM - .xxxx |
| * A8_UNORM - .000x |
| * L8_UNORM - .xxx1 |
| * |
| * If L8_UNORM, options->swizzle_xxxx is true. Otherwise we can just use |
| * the .w comp. |
| * |
| * Run before nir_lower_io. |
| */ |
| |
| static nir_variable * |
| get_texcoord(nir_shader *shader) |
| { |
| nir_variable *texcoord = |
| nir_find_variable_with_location(shader, nir_var_shader_in, |
| VARYING_SLOT_TEX0); |
| /* otherwise create it: */ |
| if (texcoord == NULL) { |
| texcoord = nir_variable_create(shader, |
| nir_var_shader_in, |
| glsl_vec4_type(), |
| "gl_TexCoord"); |
| texcoord->data.location = VARYING_SLOT_TEX0; |
| } |
| |
| return texcoord; |
| } |
| |
| static void |
| lower_bitmap(nir_shader *shader, nir_builder *b, |
| const nir_lower_bitmap_options *options) |
| { |
| nir_ssa_def *texcoord; |
| nir_tex_instr *tex; |
| nir_ssa_def *cond; |
| nir_intrinsic_instr *discard; |
| |
| texcoord = nir_load_var(b, get_texcoord(shader)); |
| |
| const struct glsl_type *sampler2D = |
| glsl_sampler_type(GLSL_SAMPLER_DIM_2D, false, false, GLSL_TYPE_FLOAT); |
| |
| nir_variable *tex_var = |
| nir_variable_create(shader, nir_var_uniform, sampler2D, "bitmap_tex"); |
| tex_var->data.binding = options->sampler; |
| tex_var->data.explicit_binding = true; |
| tex_var->data.how_declared = nir_var_hidden; |
| |
| nir_deref_instr *tex_deref = nir_build_deref_var(b, tex_var); |
| |
| tex = nir_tex_instr_create(shader, 3); |
| tex->op = nir_texop_tex; |
| tex->sampler_dim = GLSL_SAMPLER_DIM_2D; |
| tex->coord_components = 2; |
| tex->dest_type = nir_type_float; |
| tex->src[0].src_type = nir_tex_src_texture_deref; |
| tex->src[0].src = nir_src_for_ssa(&tex_deref->dest.ssa); |
| tex->src[1].src_type = nir_tex_src_sampler_deref; |
| tex->src[1].src = nir_src_for_ssa(&tex_deref->dest.ssa); |
| tex->src[2].src_type = nir_tex_src_coord; |
| tex->src[2].src = |
| nir_src_for_ssa(nir_channels(b, texcoord, |
| (1 << tex->coord_components) - 1)); |
| |
| nir_ssa_dest_init(&tex->instr, &tex->dest, 4, 32, NULL); |
| nir_builder_instr_insert(b, &tex->instr); |
| |
| /* kill if tex != 0.0.. take .x or .w channel according to format: */ |
| cond = nir_f2b(b, nir_channel(b, &tex->dest.ssa, |
| options->swizzle_xxxx ? 0 : 3)); |
| |
| discard = nir_intrinsic_instr_create(shader, nir_intrinsic_discard_if); |
| discard->src[0] = nir_src_for_ssa(cond); |
| nir_builder_instr_insert(b, &discard->instr); |
| |
| shader->info.fs.uses_discard = true; |
| } |
| |
| static void |
| lower_bitmap_impl(nir_function_impl *impl, |
| const nir_lower_bitmap_options *options) |
| { |
| nir_builder b; |
| |
| nir_builder_init(&b, impl); |
| b.cursor = nir_before_cf_list(&impl->body); |
| |
| lower_bitmap(impl->function->shader, &b, options); |
| |
| nir_metadata_preserve(impl, nir_metadata_block_index | |
| nir_metadata_dominance); |
| } |
| |
| void |
| nir_lower_bitmap(nir_shader *shader, |
| const nir_lower_bitmap_options *options) |
| { |
| assert(shader->info.stage == MESA_SHADER_FRAGMENT); |
| |
| lower_bitmap_impl(nir_shader_get_entrypoint(shader), options); |
| } |