upgrade to Filament 1.21.0

ios/include/geometry/Transcoder.h

@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_GEOMETRY_TRANSCODER_H
+#define TNT_GEOMETRY_TRANSCODER_H
+
+#include <utils/compiler.h>
+
+#include <stddef.h>
+#include <stdint.h>
+
+namespace filament {
+namespace geometry {
+
+enum class ComponentType {
+    BYTE,   //!< If normalization is enabled, this maps from [-127,127] to [-1,+1]
+    UBYTE,  //!< If normalization is enabled, this maps from [0,255] to [0, +1]
+    SHORT,  //!< If normalization is enabled, this maps from [-32767,32767] to [-1,+1]
+    USHORT, //!< If normalization is enabled, this maps from [0,65535] to [0, +1]
+    HALF,   //!< 1 sign bit, 5 exponent bits, and 5 mantissa bits.
+};
+
+/**
+ * Creates a function object that can convert vertex attribute data into tightly packed floats.
+ *
+ * This is especially useful for 3-component formats which are not supported by all backends.
+ * e.g. The Vulkan minspec includes float3 but not short3.
+ *
+ * Usage Example:
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * using filament::geometry::Transcoder;
+ * using filament::geometry::ComponentType;
+ *
+ * Transcoder transcode({
+ *     .componentType = ComponentType::BYTE,
+ *     .normalized = true,
+ *     .componentCount = 3,
+ *     .inputStrideBytes = 0
+ * });
+ *
+ * transcode(outputPtr, inputPtr, count);
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * The interpretation of signed normalized data is consistent with Vulkan and OpenGL ES 3.0+.
+ * Note that this slightly differs from earlier versions of OpenGL ES.  For example, a signed byte
+ * value of -127 maps exactly to -1.0f under ES3 and VK rules, but not ES2.
+ */
+class UTILS_PUBLIC Transcoder {
+public:
+    /**
+     * Describes the format of all input data that get passed to this transcoder object.
+     */
+    struct Config {
+        ComponentType componentType;
+        bool normalized;
+        uint32_t componentCount;
+        uint32_t inputStrideBytes = 0; //!< If stride is 0, the transcoder assumes tight packing.
+    };
+
+    /**
+     * Creates an immutable function object with the specified configuration.
+     *
+     * The config is not passed by const reference to allow for type inference at the call site.
+     */
+    Transcoder(Config config) noexcept : mConfig(config) {}
+
+    /**
+     * Converts arbitrary data into tightly packed 32-bit floating point values.
+     *
+     * If target is non-null, writes up to "count" items into target and returns the number of bytes
+     * actually written.
+     *
+     * If target is null, returns the number of bytes required.
+     *
+     * @param target Client owned area to write into, or null for a size query
+     * @param source Pointer to the data to read from (does not get retained)
+     * @param count The maximum number of items to write (i.e. number of float3 values, not bytes)
+     * @return Number of bytes required to contain "count" items after conversion to packed floats
+     *
+     */
+    size_t operator()(float* UTILS_RESTRICT target, void const* UTILS_RESTRICT source,
+            size_t count) const noexcept;
+
+private:
+    const Config mConfig;
+};
+
+} // namespace geometry
+} // namespace filament
+
+#endif // TNT_GEOMETRY_TRANSCODER_H