add multiply texture

src/textures/CMakeLists.txt

@@ -3,7 +3,7 @@ luisa_render_add_plugin(constant CATEGORY texture SOURCES constant.cpp)
 luisa_render_add_plugin(image CATEGORY texture SOURCES image.cpp)
 luisa_render_add_plugin(swizzle CATEGORY texture SOURCES swizzle.cpp)
 luisa_render_add_plugin(scale CATEGORY texture SOURCES scale.cpp)
-luisa_render_add_plugin(concat CATEGORY texture SOURCES concat.cpp)
+luisa_render_add_plugin(multiply CATEGORY texture SOURCES multiply.cpp)
 luisa_render_add_plugin(checkerboard CATEGORY texture SOURCES checkerboard.cpp)
 
 # sky texture precomputation

src/textures/multiply.cpp

@@ -0,0 +1,69 @@
+//
+// Created by mike on 4/17/24.
+//
+
+#include <base/texture.h>
+#include <base/scene.h>
+#include <base/pipeline.h>
+
+namespace luisa::render {
+
+class MultiplyTexture final : public Texture {
+
+private:
+    Texture *_a;
+    Texture *_b;
+
+public:
+    MultiplyTexture(Scene *scene, const SceneNodeDesc *desc) noexcept
+        : Texture{scene, desc},
+          _a{scene->load_texture(desc->property_node("a"))},
+          _b{scene->load_texture(desc->property_node("b"))} {}
+
+    [[nodiscard]] auto a() const noexcept { return _a; }
+    [[nodiscard]] auto b() const noexcept { return _b; }
+    [[nodiscard]] bool is_black() const noexcept override { return _a->is_black() || _b->is_black(); }
+    [[nodiscard]] bool is_constant() const noexcept override { return is_black() || (_a->is_constant() && _b->is_constant()); }
+    [[nodiscard]] luisa::optional<float4> evaluate_static() const noexcept override {
+        if (auto a = _a->evaluate_static(),
+            b = _b->evaluate_static();
+            a && b) {
+            return a.value() * b.value();
+        }
+        return nullopt;
+    }
+    [[nodiscard]] luisa::string_view impl_type() const noexcept override { return LUISA_RENDER_PLUGIN_NAME; }
+    [[nodiscard]] uint channels() const noexcept override { return std::min(_a->channels(), _b->channels()); }
+    [[nodiscard]] luisa::unique_ptr<Instance> build(
+        Pipeline &pipeline, CommandBuffer &command_buffer) const noexcept override;
+};
+
+class MultiplyTextureInstance final : public Texture::Instance {
+
+private:
+    const Texture::Instance *_a;
+    const Texture::Instance *_b;
+
+public:
+    MultiplyTextureInstance(const Pipeline &pipeline,
+                            const Texture *node,
+                            const Texture::Instance *a,
+                            const Texture::Instance *b) noexcept
+        : Texture::Instance{pipeline, node}, _a{a}, _b{b} {}
+    [[nodiscard]] Float4 evaluate(const Interaction &it,
+                                  const SampledWavelengths &swl,
+                                  Expr<float> time) const noexcept override {
+        return _a->evaluate(it, swl, time) * _b->evaluate(it, swl, time);
+    }
+};
+
+luisa::unique_ptr<Texture::Instance> MultiplyTexture::build(
+    Pipeline &pipeline, CommandBuffer &command_buffer) const noexcept {
+    auto a = pipeline.build_texture(command_buffer, _a);
+    auto b = pipeline.build_texture(command_buffer, _b);
+    return luisa::make_unique<MultiplyTextureInstance>(pipeline, this, a, b);
+}
+
+}// namespace luisa::render
+
+LUISA_RENDER_MAKE_SCENE_NODE_PLUGIN(luisa::render::MultiplyTexture)