// Copyright 2022 The Dawn & Tint Authors // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are met: // // 1. Redistributions of source code must retain the above copyright notice, this // list of conditions and the following disclaimer. // // 2. Redistributions in binary form must reproduce the above copyright notice, // this list of conditions and the following disclaimer in the documentation // and/or other materials provided with the distribution. // // 3. Neither the name of the copyright holder nor the names of its // contributors may be used to endorse or promote products derived from // this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. #ifndef SRC_TINT_LANG_GLSL_WRITER_AST_RAISE_COMBINE_SAMPLERS_H_ #define SRC_TINT_LANG_GLSL_WRITER_AST_RAISE_COMBINE_SAMPLERS_H_ #include <string> #include <unordered_map> #include "src/tint/lang/wgsl/ast/transform/transform.h" namespace tint::glsl::writer { /// This transform converts all separate texture/sampler refences in a /// program into combined texture/samplers. This is required for GLSL, /// which does not support separate texture/samplers. /// /// It utilizes the texture/sampler information collected by the /// Resolver and stored on each sem::Function. For each function, all /// separate texture/sampler parameters in the function signature are /// removed. For each unique pair, if both texture and sampler are /// global variables, the function passes the corresponding combined /// global stored in global_combined_texture_samplers_ at the call /// site. Otherwise, either the texture or sampler must be a function /// parameter. In this case, a new parameter is added to the function /// signature. All separate texture/sampler parameters are removed. /// /// All texture builtin callsites are modified to pass the combined /// texture/sampler as the first argument, and separate texture/sampler /// arguments are removed. /// /// Note that the sampler may be null, indicating that only a texture /// reference was required (e.g., textureLoad). In this case, a /// placeholder global sampler is used at the AST level. This will be /// combined with the original texture to give a combined global, and /// the placeholder removed (ignored) by the GLSL writer. /// /// Note that the combined samplers are actually represented by a /// Texture node at the AST level, since this contains all the /// information needed to represent a combined sampler in GLSL /// (dimensionality, component type, etc). The GLSL writer outputs such /// (Tint) Textures as (GLSL) Samplers. class CombineSamplers final : public Castable<CombineSamplers, ast::transform::Transform> { … }; } // namespace tint::glsl::writer #endif // SRC_TINT_LANG_GLSL_WRITER_AST_RAISE_COMBINE_SAMPLERS_H_