[Mesa-dev] [PATCH] nir: add lowering pass for glBitmap

Connor Abbott cwabbott0 at gmail.com
Thu Apr 14 22:47:12 UTC 2016


This looks much better :) both patches LGTM.

On Thu, Apr 14, 2016 at 6:44 PM, Rob Clark <robdclark at gmail.com> wrote:
> From: Rob Clark <robclark at freedesktop.org>
>
> Signed-off-by: Rob Clark <robclark at freedesktop.org>
> Reviewed-by: Connor Abbott <cwabbott0 at gmail.com>
> ---
>  src/compiler/Makefile.sources       |   1 +
>  src/compiler/nir/nir.h              |   7 ++
>  src/compiler/nir/nir_lower_bitmap.c | 139 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 147 insertions(+)
>  create mode 100644 src/compiler/nir/nir_lower_bitmap.c
>
> diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
> index 290ed35..8d8eca2 100644
> --- a/src/compiler/Makefile.sources
> +++ b/src/compiler/Makefile.sources
> @@ -186,6 +186,7 @@ NIR_FILES = \
>         nir/nir_liveness.c \
>         nir/nir_lower_alu_to_scalar.c \
>         nir/nir_lower_atomics.c \
> +       nir/nir_lower_bitmap.c \
>         nir/nir_lower_clip.c \
>         nir/nir_lower_double_packing.c \
>         nir/nir_lower_drawpixels.c \
> diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
> index bdc9e8b..c334702 100644
> --- a/src/compiler/nir/nir.h
> +++ b/src/compiler/nir/nir.h
> @@ -2301,6 +2301,13 @@ typedef struct nir_lower_drawpixels_options {
>  void nir_lower_drawpixels(nir_shader *shader,
>                            const nir_lower_drawpixels_options *options);
>
> +typedef struct nir_lower_bitmap_options {
> +   unsigned sampler;
> +   bool swizzle_xxxx;
> +} nir_lower_bitmap_options;
> +
> +void nir_lower_bitmap(nir_shader *shader, const nir_lower_bitmap_options *options);
> +
>  void nir_lower_atomics(nir_shader *shader,
>                         const struct gl_shader_program *shader_program);
>  void nir_lower_to_source_mods(nir_shader *shader);
> diff --git a/src/compiler/nir/nir_lower_bitmap.c b/src/compiler/nir/nir_lower_bitmap.c
> new file mode 100644
> index 0000000..49211e3
> --- /dev/null
> +++ b/src/compiler/nir/nir_lower_bitmap.c
> @@ -0,0 +1,139 @@
> +/*
> + * 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 = NULL;
> +
> +   /* find gl_TexCoord, if it exists: */
> +   nir_foreach_variable(var, &shader->inputs) {
> +      if (var->data.location == VARYING_SLOT_TEX0) {
> +         texcoord = var;
> +         break;
> +      }
> +   }
> +
> +   /* 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));
> +
> +   tex = nir_tex_instr_create(shader, 1);
> +   tex->op = nir_texop_tex;
> +   tex->sampler_dim = GLSL_SAMPLER_DIM_2D;
> +   tex->coord_components = 2;
> +   tex->sampler_index = options->sampler;
> +   tex->texture_index = options->sampler;
> +   tex->dest_type = nir_type_float;
> +   tex->src[0].src = nir_src_for_ssa(texcoord);
> +
> +   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);
> +}
> +
> +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_node(&impl->cf_node);
> +
> +   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)
> +{
> +   nir_function *function;
> +
> +   assert(shader->stage == MESA_SHADER_FRAGMENT);
> +
> +   function = nir_shader_get_entrypoint(shader);
> +
> +   if (function->impl)
> +      lower_bitmap_impl(function->impl, options);
> +}
> --
> 2.5.5
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev


More information about the mesa-dev mailing list