[Examples] Refactored asset loading in examples.

- Replaced filename resolution via FindResourcePath() with abstraction to load entire asset via ReadAsset(). - Replaced individual uses of stbi_load() with new ImageReader class. - Started with asset loading for Android. - Also use different header guard for examples: Renamed "LLGL_*" to "LLGLEXAMPLES_*". TODO: Android asset reading will need connection to JNI to access 'AAssetManager'.
LukasBanana · Jul 6, 2024 · 1047789 · 1047789
1 parent 561e6ab
commit 1047789
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diff --git a/examples/Cpp/CMakeLists.txt b/examples/Cpp/CMakeLists.txt
@@ -21,16 +21,20 @@ if(APPLE)
     else()
         find_source_files(FilesExampleBaseMacOS OBJC "${EXAMPLEBASE_PROJECT_DIR}/macOS")
     endif()
-endif(APPLE)
+elseif(LLGL_ANDROID_PLATFORM)
+    find_source_files(FilesExampleBaseAndroid CXX "${EXAMPLEBASE_PROJECT_DIR}/Android")
+endif()
 
 set(FilesExampleBaseAll ${FilesExampleBase})
 if(APPLE)
     if(LLGL_IOS_PLATFORM)
-        set(FilesExampleBaseAll ${FilesExampleBaseAll} ${FilesExampleBaseIOS})
+        list(APPEND FilesExampleBaseAll ${FilesExampleBaseIOS})
     else()
-        set(FilesExampleBaseAll ${FilesExampleBaseAll} ${FilesExampleBaseMacOS})
+        list(APPEND FilesExampleBaseAll ${FilesExampleBaseMacOS})
     endif()
     set_source_files_properties("${EXAMPLEBASE_PROJECT_DIR}/ExampleBase.cpp" PROPERTIES COMPILE_FLAGS -xobjective-c++)
+elseif(LLGL_ANDROID_PLATFORM)
+    list(APPEND FilesExampleBaseAll ${FilesExampleBaseAndroid})
 endif()
 
 find_project_source_files( FilesExample_Animation           "${EXAMPLE_CPP_PROJECTS_DIR}/Animation"        )
@@ -130,7 +134,9 @@ if(APPLE)
     else()
         source_group("Sources\\macOS" FILES ${FilesExampleBaseMacOS})
     endif()
-endif(APPLE)
+elseif(LLGL_ANDROID_PLATFORM)
+    source_group("Sources\\Android" FILES ${FilesExampleBaseAndroid})
+endif()
 
 
 # === Include directories ===

diff --git a/examples/Cpp/ExampleBase/Android/AppUtils.c b/examples/Cpp/ExampleBase/Android/AppUtils.c
@@ -0,0 +1,56 @@
+/*
+ * AppUtils.c (Android)
+ *
+ * Copyright (c) 2015 Lukas Hermanns. All rights reserved.
+ * Licensed under the terms of the BSD 3-Clause license (see LICENSE.txt).
+ */
+
+#include "AppUtils.h"
+#include <errno.h>
+
+
+static int AndroidFileRead(void* userData, char* buffer, int size)
+{
+    return AAsset_read((AAsset*)userData, buffer, (size_t)size);
+}
+
+static int AndroidFileWrite(void* userData, const char* buffer, int size)
+{
+    return EACCES; // dummy - cannot provide access to write to APK
+}
+
+static fpos_t AndroidFileSeek(void* userData, fpos_t offset, int whence)
+{
+    return AAsset_seek((AAsset*)userData, offset, whence);
+}
+
+static int AndroidFileClose(void* userData)
+{
+    AAsset_close((AAsset*)userData);
+    return 0;
+}
+
+static AAssetManager* g_assetMngr = NULL;
+
+void AndroidSetAssetManager(AAssetManager* assetMngr)
+{
+    g_assetMngr = assetMngr;
+}
+
+FILE* AndroidOpenFile(const char* filename, const char* mode)
+{
+    if (g_assetMngr == NULL)
+        return NULL; // No asset manager provided
+
+    if (mode[0] == 'w')
+        return NULL; // Write access is not supported on APK package
+
+    // Open asset via AAssetManager
+    AAsset* asset = AAssetManager_open(g_assetMngr, filename, AASSET_MODE_STREAMING);
+    if (asset == NULL)
+        return NULL; // Failed to open asset
+
+    // Open FILE descriptor with custom read/seek functions
+    return funopen(asset, AndroidFileRead, AndroidFileWrite, AndroidFileSeek, AndroidFileClose);
+}
+
diff --git a/examples/Cpp/ExampleBase/Android/AppUtils.h b/examples/Cpp/ExampleBase/Android/AppUtils.h
@@ -0,0 +1,29 @@
+/*
+ * AppUtils.h (Android)
+ *
+ * Copyright (c) 2015 Lukas Hermanns. All rights reserved.
+ * Licensed under the terms of the BSD 3-Clause license (see LICENSE.txt).
+ */
+
+#ifndef __USE_BSD
+#define __USE_BSD /* Defines funopen() */
+#endif
+
+#include <stdio.h>
+#include <android/asset_manager.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Sets the current asset manager.
+void AndroidSetAssetManager(AAssetManager* assetMngr);
+
+// Opens an STD file stream via the AAssetManager.
+FILE* AndroidOpenFile(const char* filename, const char* mode);
+
+#define fopen(NAME, MODE) AndroidOpenFile(NAME, MODE)
+
+#ifdef __cplusplus
+} // /extern "C"
+#endif
diff --git a/examples/Cpp/ExampleBase/DDSImageReader.cpp b/examples/Cpp/ExampleBase/DDSImageReader.cpp
@@ -12,6 +12,7 @@
 #include <cstring>
 #include <type_traits>
 #include <algorithm>
+#include <LLGL/Log.h>
 
 
 static const std::uint32_t ddsMagicNumber = 0x20534444; // 'DDS '
@@ -131,21 +132,22 @@ T ReadValue(std::istream& stream)
     return value;
 }
 
-void DDSImageReader::LoadFromFile(const std::string& filename)
+bool DDSImageReader::LoadFromFile(const std::string& filename)
 {
     // Open file for reading
-    const std::string path = FindResourcePath(filename);
-    std::ifstream file(path, std::ios::binary);
-    if (!file.good())
-        throw std::runtime_error("failed to load DDS image from file: " + path);
+    AssetReader reader = ReadAsset(filename);
+    if (!reader)
+        return false;
 
     // Read magic number
-    if (ReadValue<std::int32_t>(file) != ddsMagicNumber)
-        throw std::runtime_error("invalid magic number in DDS image: " + path);
+    if (reader.Read<std::int32_t>() != ddsMagicNumber)
+    {
+        LLGL::Log::Errorf("invalid magic number in DDS image: %s\n", filename.c_str());
+        return false;
+    }
 
     // Rerad DDS header
-    DDSHeader header;
-    ReadValue(file, header);
+    DDSHeader header = reader.Read<DDSHeader>();
 
     DDSHeaderDX10 headerDX10;
     ::memset(&headerDX10, 0, sizeof(headerDX10));
@@ -207,7 +209,7 @@ void DDSImageReader::LoadFromFile(const std::string& filename)
     /*else if (IsFourCC("DX10"))
     {
         // Read header extension
-        ReadValue(file, headerDX10);
+        (void)reader.Read<headerDX10>();
         hasDX10Header = true;
     }*/
     else
@@ -244,7 +246,9 @@ void DDSImageReader::LoadFromFile(const std::string& filename)
 
     data_.resize(bufferSize);
 
-    file.read(data_.data(), static_cast<std::streamsize>(data_.size()));
+    reader.Read(data_.data(), static_cast<std::streamsize>(data_.size()));
+
+    return true;
 }
 
 LLGL::ImageView DDSImageReader::GetImageView(std::uint32_t mipLevel) const

diff --git a/examples/Cpp/ExampleBase/DDSImageReader.h b/examples/Cpp/ExampleBase/DDSImageReader.h
@@ -5,8 +5,8 @@
  * Licensed under the terms of the BSD 3-Clause license (see LICENSE.txt).
  */
 
-#ifndef LLGL_DDS_IMAGE_READER_H
-#define LLGL_DDS_IMAGE_READER_H
+#ifndef LLGLEXAMPLES_DDS_IMAGE_READER_H
+#define LLGLEXAMPLES_DDS_IMAGE_READER_H
 
 
 #include <LLGL/ImageFlags.h>
@@ -15,14 +15,14 @@
 #include <vector>
 
 
-// Perlin noise generator class.
+// Image reader class to load DXT compressed textures from file.
 class DDSImageReader
 {
 
     public:
 
-        // Loads the specified DDS texture from file.
-        void LoadFromFile(const std::string& filename);
+        // Loads the specified DDS image from file.
+        bool LoadFromFile(const std::string& filename);
 
         // Returns the image view for the sepcified MIP-map that can be passed to RenderSystem::CreateTexture or RenderSystem::WriteTexture.
         LLGL::ImageView GetImageView(std::uint32_t mipLevel = 0) const;

diff --git a/examples/Cpp/ExampleBase/ExampleBase.cpp b/examples/Cpp/ExampleBase/ExampleBase.cpp
@@ -8,6 +8,7 @@
 #include <ExampleBase.h>
 #include <LLGL/Utils/TypeNames.h>
 #include <LLGL/Utils/ForRange.h>
+#include "ImageReader.h"
 #include "FileUtils.h"
 #include <stdio.h>
 
@@ -26,6 +27,10 @@
 #endif
 #include <inttypes.h>
 
+#ifdef LLGL_OS_ANDROID
+#   include "Android/AppUtils.h"
+#endif
+
 #define IMMEDIATE_SUBMIT_CMDBUFFER 0
 
 
@@ -483,6 +488,18 @@ ExampleBase::ExampleBase(const LLGL::UTF8String& title)
     rendererDesc.flags |= g_Config.flags;
     renderer = LLGL::RenderSystem::Load(rendererDesc);
 
+    // Fallback to null device if selected renderer cannot be loaded
+    if (!renderer)
+    {
+        LLGL::Log::Errorf("Failed to load \"%s\" module. Falling back to \"Null\" device.\n", rendererDesc.moduleName.c_str());
+        renderer = LLGL::RenderSystem::Load("Null");
+        if (!renderer)
+        {
+            LLGL::Log::Errorf("Failed to load \"Null\" module. Exiting.\n");
+            exit(1);
+        }
+    }
+
     // Apply device limits (not for GL, because we won't have a valid GL context until we create our first swap chain)
     if (renderer->GetRendererID() == LLGL::RendererID::OpenGL)
         samples_ = g_Config.samples;
@@ -514,8 +531,8 @@ ExampleBase::ExampleBase(const LLGL::UTF8String& title)
     commandQueue = renderer->GetCommandQueue();
 
     // Print renderer information
-    const auto& info = renderer->GetRendererInfo();
-    const auto swapChainRes = swapChain->GetResolution();
+    const LLGL::RendererInfo& info = renderer->GetRendererInfo();
+    const LLGL::Extent2D swapChainRes = swapChain->GetResolution();
 
     LLGL::Log::Printf(
         "render system:\n"
@@ -775,40 +792,17 @@ void ExampleBase::ThrowIfFailed(LLGL::PipelineState* pso)
 
 LLGL::Texture* LoadTextureWithRenderer(LLGL::RenderSystem& renderSys, const std::string& filename, long bindFlags, LLGL::Format format)
 {
-    // Get format informationm
-    const auto formatAttribs = LLGL::GetFormatAttribs(format);
-
     // Load image data from file (using STBI library, see https://github.com/nothings/stb)
-    int width = 0, height = 0, components = 0;
-
-    const std::string path = FindResourcePath(filename);
-    stbi_uc* imageBuffer = stbi_load(path.c_str(), &width, &height, &components, static_cast<int>(formatAttribs.components));
-    if (!imageBuffer)
-        throw std::runtime_error("failed to load texture from file: \"" + path + "\"");
-
-    // Initialize source image descriptor to upload image data onto hardware texture
-    LLGL::ImageView imageView;
+    ImageReader reader;
+    if (!reader.LoadFromFile(filename))
     {
-        // Set image color format
-        imageView.format    = formatAttribs.format;
-
-        // Set image data type (unsigned char = 8-bit unsigned integer)
-        imageView.dataType  = LLGL::DataType::UInt8;
-
-        // Set image buffer source for texture initial data
-        imageView.data      = imageBuffer;
-
-        // Set image buffer size
-        imageView.dataSize  = static_cast<std::size_t>(width*height*4);
+        // Create dummy texture on load failure
+        return renderSys.CreateTexture(LLGL::Texture2DDesc(format, 1, 1));
     }
 
     // Create texture and upload image data onto hardware texture
-    LLGL::TextureDescriptor texDesc = LLGL::Texture2DDesc(format, width, height, bindFlags);
-    texDesc.debugName = filename.c_str();
-    LLGL::Texture* tex = renderSys.CreateTexture(texDesc, &imageView);
-
-    // Release image data
-    stbi_image_free(imageBuffer);
+    LLGL::ImageView imageView = reader.GetImageView();
+    LLGL::Texture* tex = renderSys.CreateTexture(reader.GetTextureDesc(), &imageView);
 
     // Show info
     LLGL::Log::Printf("loaded texture: %s\n", filename.c_str());
@@ -818,17 +812,8 @@ LLGL::Texture* LoadTextureWithRenderer(LLGL::RenderSystem& renderSys, const std:
 
 bool SaveTextureWithRenderer(LLGL::RenderSystem& renderSys, LLGL::Texture& texture, const std::string& filename, std::uint32_t mipLevel)
 {
-    #if 0//TESTING
-
-    mipLevel = 1;
-    LLGL::Extent3D texSize{ 150, 256, 1 };
-
-    #else
-
     // Get texture dimension
-    auto texSize = texture.GetMipExtent(mipLevel);
-
-    #endif
+    const LLGL::Extent3D texSize = texture.GetMipExtent(mipLevel);
 
     // Read texture image data
     std::vector<LLGL::ColorRGBAub> imageBuffer(texSize.width * texSize.height);