Add ahb mapping util functions to map ahb usage and format to TextureUsage and TextureFormat (#8491)

Author: alizahlalani

filament/backend/CMakeLists.txt

@@ -246,6 +246,10 @@ if (FILAMENT_SUPPORTS_WEBGPU)
     )
 endif()
 
+if (ANDROID)
+    list(APPEND SRCS src/BackendUtilsAndroid.cpp)
+endif()
+
 # ==================================================================================================
 # Definitions
 # ==================================================================================================

filament/backend/include/backend/DriverEnums.h

@@ -807,6 +807,33 @@ static constexpr bool isStencilFormat(TextureFormat format) noexcept {
     }
 }
 
+inline constexpr bool isColorFormat(TextureFormat format) noexcept {
+    switch (format) {
+        // Standard color formats
+        case TextureFormat::R8:
+        case TextureFormat::RG8:
+        case TextureFormat::RGBA8:
+        case TextureFormat::R16F:
+        case TextureFormat::RG16F:
+        case TextureFormat::RGBA16F:
+        case TextureFormat::R32F:
+        case TextureFormat::RG32F:
+        case TextureFormat::RGBA32F:
+        case TextureFormat::RGB10_A2:
+        case TextureFormat::R11F_G11F_B10F:
+        case TextureFormat::SRGB8:
+        case TextureFormat::SRGB8_A8:
+        case TextureFormat::RGB8:
+        case TextureFormat::RGB565:
+        case TextureFormat::RGB5_A1:
+        case TextureFormat::RGBA4:
+            return true;
+        default:
+            break;
+    }
+    return false;
+}
+
 static constexpr bool isUnsignedIntFormat(TextureFormat format) {
     switch (format) {
         case TextureFormat::R8UI:

filament/backend/include/private/backend/BackendUtilsAndroid.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2025 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_FILAMENT_BACKEND_PRIVATE_BACKENDUTILSANDROID_H
+#define TNT_FILAMENT_BACKEND_PRIVATE_BACKENDUTILSANDROID_H
+
+#include <backend/DriverEnums.h>
+
+namespace filament::backend {
+
+/**
+ * Maps AHardwareBuffer format to TextureFormat.
+ */
+TextureFormat mapToFilamentFormat(unsigned int format, bool isSrgbTransfer) noexcept;
+
+/**
+ * Maps AHardwareBuffer usage to TextureUsage.
+ */
+TextureUsage mapToFilamentUsage(unsigned int usage, TextureFormat format) noexcept;
+
+} // namespace filament
+
+#endif // TNT_FILAMENT_BACKEND_PRIVATE_BACKENDUTILSANDROID_H

filament/backend/src/BackendUtilsAndroid.cpp

@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2025 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.
+ */
+
+#include "private/backend/BackendUtilsAndroid.h"
+
+#include <android/hardware_buffer.h>
+
+namespace filament::backend {
+
+TextureFormat mapToFilamentFormat(unsigned int format, bool isSrgbTransfer) noexcept {
+    if (isSrgbTransfer) {
+        switch (format) {
+            case AHARDWAREBUFFER_FORMAT_R8G8B8_UNORM:
+                return TextureFormat::SRGB8;
+            default:
+                return TextureFormat::SRGB8_A8;
+        }
+    }
+    switch (format) {
+        case AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM:
+        case AHARDWAREBUFFER_FORMAT_R8G8B8X8_UNORM:
+            return TextureFormat::RGBA8;
+        case AHARDWAREBUFFER_FORMAT_R8G8B8_UNORM:
+        case AHARDWAREBUFFER_FORMAT_Y8Cb8Cr8_420:
+            return TextureFormat::RGB8;
+        case AHARDWAREBUFFER_FORMAT_R5G6B5_UNORM:
+            return TextureFormat::RGB565;
+        case AHARDWAREBUFFER_FORMAT_R16G16B16A16_FLOAT:
+            return TextureFormat::RGBA16F;
+        case AHARDWAREBUFFER_FORMAT_R10G10B10A2_UNORM:
+            return TextureFormat::RGB10_A2;
+        case AHARDWAREBUFFER_FORMAT_D16_UNORM:
+            return TextureFormat::DEPTH16;
+        case AHARDWAREBUFFER_FORMAT_D24_UNORM:
+            return TextureFormat::DEPTH24;
+        case AHARDWAREBUFFER_FORMAT_D24_UNORM_S8_UINT:
+            return TextureFormat::DEPTH24_STENCIL8;
+        case AHARDWAREBUFFER_FORMAT_D32_FLOAT:
+            return TextureFormat::DEPTH32F;
+        case AHARDWAREBUFFER_FORMAT_D32_FLOAT_S8_UINT:
+            return TextureFormat::DEPTH32F_STENCIL8;
+        case AHARDWAREBUFFER_FORMAT_S8_UINT:
+            return TextureFormat::STENCIL8;
+        case AHARDWAREBUFFER_FORMAT_R8_UNORM:
+            return TextureFormat::R8;
+        default:
+            return TextureFormat::UNUSED;
+    }
+}
+
+TextureUsage mapToFilamentUsage(unsigned int usage, TextureFormat format) noexcept {
+    TextureUsage usageFlags = TextureUsage::NONE;
+
+    if (usage & AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE) {
+        usageFlags |= TextureUsage::SAMPLEABLE;
+    }
+
+    if (usage & AHARDWAREBUFFER_USAGE_GPU_FRAMEBUFFER) {
+        if (isDepthFormat(format)) {
+            usageFlags |= TextureUsage::DEPTH_ATTACHMENT;
+        }
+        if (isStencilFormat(format)) {
+            usageFlags |= TextureUsage::STENCIL_ATTACHMENT;
+        }
+        if (isColorFormat(format)) {
+            usageFlags |= TextureUsage::COLOR_ATTACHMENT;
+        }
+    }
+
+    if (usage & AHARDWAREBUFFER_USAGE_GPU_DATA_BUFFER) {
+        usageFlags |= TextureUsage::UPLOADABLE;
+    }
+
+    if (usage & AHARDWAREBUFFER_USAGE_PROTECTED_CONTENT) {
+        usageFlags |= TextureUsage::PROTECTED;
+    }
+
+    if (usageFlags == TextureUsage::NONE) {
+        usageFlags = TextureUsage::COLOR_ATTACHMENT | TextureUsage::SAMPLEABLE;
+    }
+
+    return usageFlags;
+}
+
+} // namespace backend::filament