# Work at gfx driver system

- Update pool to use template allocator directly instead of std::vector
- Add a GfxDriver config Template to be able to modify settings like allocators / Types for specific Drivers
- Add glad

.gitattributes

@@ -0,0 +1 @@
+vendor/* linguist-vendored

CMakeLists.txt

@@ -17,8 +17,11 @@ if(${PD_BUILD_TOOLS})
     add_subdirectory(tools)
 endif()
 
+add_subdirectory(vendor)
+
 # # Include Library Source
 set(PD_SOURCES
+
     # Core
     source/core/bits.cpp
     source/core/color.cpp
@@ -26,6 +29,7 @@ set(PD_SOURCES
     source/core/strings.cpp
 
     source/drivers/os.cpp
+    source/drivers/gfx.cpp
 )
 
 if(${PD_BUILD_SHARED})
@@ -83,7 +87,6 @@ install(FILES
     DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/palladium
 )
 
-
 find_program(CLANG_FORMAT clang-format)
 
 file(GLOB_RECURSE PD_FMTFILES CONFIGURE_DEPENDS
@@ -96,4 +99,5 @@ add_custom_target(pd-clang-format
     COMMENT "Formatting Project Sources"
 )
 
+add_subdirectory(backends)
 add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/tests)

backends/CMakeLists.txt

@@ -0,0 +1,21 @@
+cmake_minimum_required(VERSION 3.22)
+
+project(pd-system)
+
+option(PD_ENABLE_OPENGL2 "Enable OpenGL 2.1 (On Supported Hardware)" ON)
+option(PD_ENABLE_OPENGL3 "Enable OpenGL 3.3 (On Supported Hardware)" ON)
+option(PD_ENABLE_VULKAN "Not implemented yet" OFF)
+
+add_library(pd-system STATIC
+    ${CMAKE_CURRENT_SOURCE_DIR}/source/gfx_opengl.cpp
+)
+target_include_directories(pd-system
+    PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+    $<INSTALL_INTERFACE:include>
+)
+target_link_libraries(pd-system
+    PUBLIC
+    palladium::palladium
+    glad
+)

backends/include/gfx_opengl.hpp

@@ -0,0 +1,42 @@
+#pragma once
+
+#include <pd/drivers/gfx.hpp>
+
+namespace PD {
+struct GfxOpenGLConfig {
+  // Vertex Allocator
+  template <typename T>
+  using VertexAlloc = std::allocator<T>;
+  // Index Allocator
+  template <typename T>
+  using IndexAlloc = std::allocator<T>;
+  using IndexType = u32;  // Index Type
+
+  static constexpr size_t NumVertices = 32768;  // 8192*4
+  static constexpr size_t NumIndices = 49152;   // 8192*6
+};
+class GfxOpenGL : public GfxDriverBase<GfxOpenGLConfig> {
+ public:
+  GfxOpenGL() {}
+  ~GfxOpenGL() {}
+
+  void SysInit() override;
+  void SysDeinit() override;
+  void Submit(size_t count, size_t start) override;
+  void BindTexture(TextureID id) override;
+  void SysReset() override;
+  TextureID LoadTexture(const std::vector<PD::u8>& pixels, int w, int h,
+                        TextureFormat type = TextureFormat::RGBA32,
+                        TextureFilter filter = TextureFilter::Linear) override;
+  void DeleteTexture(const TextureID& tex) override;
+
+ private:
+  void pSetupShaderAttribs(u32 shader);
+  u32 pShader = 0;
+  u32 VBO = 0;
+  u32 IBO = 0;
+  int pLocTex = 0;
+  int pLocAlfa = 0;
+  int pLocProjection = 0;
+};
+}  // namespace PD

backends/source/gfx_opengl.cpp

@@ -0,0 +1,154 @@
+#include <glad/glad.h>
+
+#include <gfx_opengl.hpp>
+
+namespace PD {
+GLuint compileShader(const std::string& source, GLenum type) {
+  GLuint shader = glCreateShader(type);
+  const char* src = source.c_str();
+  glShaderSource(shader, 1, &src, nullptr);
+  glCompileShader(shader);
+
+  GLint success;
+  glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
+  if (!success) {
+    char infoLog[512];
+    glGetShaderInfoLog(shader, 512, nullptr, infoLog);
+    std::cerr << "Shader Compilation Error: " << infoLog << std::endl;
+  }
+
+  return shader;
+}
+
+GLuint createShaderProgram(const std::string& vertexShaderSource,
+                           const std::string& fragmentShaderSource) {
+  GLuint vertexShader = compileShader(vertexShaderSource, GL_VERTEX_SHADER);
+  GLuint fragmentShader =
+      compileShader(fragmentShaderSource, GL_FRAGMENT_SHADER);
+
+  GLuint shaderProgram = glCreateProgram();
+  glAttachShader(shaderProgram, vertexShader);
+  glAttachShader(shaderProgram, fragmentShader);
+  glLinkProgram(shaderProgram);
+
+  GLint success;
+  glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
+  if (!success) {
+    char infoLog[512];
+    glGetProgramInfoLog(shaderProgram, 512, nullptr, infoLog);
+    std::cerr << "Shader Program Linking Error: " << infoLog << std::endl;
+  }
+
+  glDeleteShader(vertexShader);
+  glDeleteShader(fragmentShader);
+
+  return shaderProgram;
+}
+
+const char* vertex_shader = R"(
+  #version 120
+  
+  attribute vec2 pos;
+  attribute vec2 uv;
+  attribute vec4 color;
+  
+  varying vec2 oUV;
+  varying vec4 oColor;
+  
+  // Probably forgot about this matrix and
+  // searched hours for why the rendering isn't working :/
+  uniform mat4 projection;
+  
+  void main() {
+      gl_Position = projection*vec4(pos, 0.0, 1.0);
+      oUV = uv;
+      oColor = color;
+  }
+  )";
+
+const char* frag_shader = R"(
+  #version 120
+      
+  varying vec2 oUV;
+  varying vec4 oColor;
+  
+  uniform sampler2D tex;
+  uniform bool alfa;
+      
+  void main() {
+    vec4 tc = texture2D(tex, oUV);
+    if (alfa) {
+      gl_FragColor = vec4(oColor.rgb, tc.a * oColor.a);
+    } else {
+      gl_FragColor = tc * oColor;
+    }
+  }
+  )";
+
+void GfxOpenGL::pSetupShaderAttribs(u32 shader) {
+  GLint _pos = glGetAttribLocation(shader, "pos");
+  GLint _uv = glGetAttribLocation(shader, "uv");
+  GLint _color = glGetAttribLocation(shader, "color");
+  glVertexAttribPointer(_pos, 2, GL_FLOAT, GL_FALSE, sizeof(PD::Li::Vertex),
+                        (void*)offsetof(PD::Li::Vertex, pos));
+  glEnableVertexAttribArray(_pos);
+
+  glVertexAttribPointer(_uv, 2, GL_FLOAT, GL_FALSE, sizeof(PD::Li::Vertex),
+                        (void*)offsetof(PD::Li::Vertex, uv));
+  glEnableVertexAttribArray(_uv);
+
+  glVertexAttribPointer(_color, 4, GL_UNSIGNED_BYTE, GL_TRUE,
+                        sizeof(PD::Li::Vertex),
+                        (void*)offsetof(PD::Li::Vertex, color));
+  glEnableVertexAttribArray(_color);
+}
+
+void GfxOpenGL::SysInit() {
+  pShader = createShaderProgram(vertex_shader, frag_shader);
+  glUseProgram(pShader);
+  glGenBuffers(1, &VBO);
+  glBindBuffer(GL_ARRAY_BUFFER, VBO);
+  pSetupShaderAttribs(pShader);
+  glGenBuffers(1, &IBO);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IBO);
+
+  pLocTex = glGetUniformLocation(pShader, "tex");
+  pLocAlfa = glGetUniformLocation(pShader, "alfa");
+  pLocProjection = glGetUniformLocation(pShader, "projection");
+
+  glBindBuffer(GL_ARRAY_BUFFER, 0);
+  glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+}
+
+void GfxOpenGL::SysDeinit() {
+  glDeleteBuffers(1, &VBO);
+  glDeleteBuffers(1, &IBO);
+}
+
+void GfxOpenGL::Submit(size_t count, size_t start) {
+  glDrawElements(GL_TRIANGLES, count, GL_UNSIGNED_INT,
+                 (void*)GetIndexBufPtr(start));
+}
+
+void GfxOpenGL::BindTexture(TextureID id) {
+  glActiveTexture(GL_TEXTURE0);
+  glBindTexture(GL_TEXTURE_2D, (GLuint)id);
+  glUniform1i(pLocTex, 0);
+  GLint fmt = 0;
+  glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_INTERNAL_FORMAT, &fmt);
+  glUniform1i(pLocAlfa, fmt == GL_ALPHA);
+}
+
+void GfxOpenGL::SysReset() {}
+
+TextureID GfxOpenGL::LoadTexture(const std::vector<PD::u8>& pixels, int w,
+                                 int h, TextureFormat type,
+                                 TextureFilter filter) {
+  return 0;
+}
+
+void GfxOpenGL::DeleteTexture(const TextureID& tex) {
+  GLuint tex_ = tex;
+  glDeleteTextures(1, &tex_);
+}
+}  // namespace PD

include/pd/common.hpp

@@ -28,6 +28,7 @@ SOFTWARE.
 #include <exception>
 #include <format>
 #include <fstream>
+#include <numbers>
 #include <pd/pd_p_api.hpp>
 #include <string>
 #include <vector>

include/pd/core/pool.hpp

@@ -1,20 +1,29 @@
 #pragma once
 
+#include <iostream>
 #include <pd/common.hpp>
-
 namespace PD {
 template <typename T, typename Alloc = std::allocator<T>>
 class Pool {
  public:
+  using value_type = T;
+  using iterator = T*;
+  using const_iterator = const iterator*;
+
   Pool() = default;
-  ~Pool() = default;
+  ~Pool() {
+    if (pData) {
+      pAlloc.deallocate(pData, pCap);
+      pData = nullptr;
+    }
+  }
 
   static Pool* Create(size_t size) { return new Pool(size); }
 
   void Init(size_t size) {
     pPos = 0;
     pCap = size;
-    pPool.resize(size);
+    pData = pAlloc.allocate(size);
   }
 
   Pool(const Pool&) = delete;
@@ -24,7 +33,7 @@ class Pool {
 
   T* Allocate(size_t num = 1) {
     if (CheckLimits(num)) return nullptr;
-    T* ret = &pPool[pPos];
+    T* ret = &pData[pPos];
     pPos += num;
     return ret;
   }
@@ -42,10 +51,19 @@ class Pool {
 
   void Reset() { pPos = 0; }
 
+  size_t size() const { return pPos; }
+  size_t capacity() const { return pCap; }
+  T& at(size_t idx) { return pData[idx]; }
+  const T& at(size_t idx) const { return pData[idx]; }
+
+  T& operator[](size_t idx) { return at(idx); }
+  const T& operator[](size_t idx) const { return at(idx); }
+
  private:
-  Pool(size_t size) : pCap(size), pPos(0) { pPool.resize(size); }
+  Pool(size_t size) : pCap(size), pPos(0) { pData = pAlloc.allocate(size); }
   size_t pCap = 0;
   size_t pPos = 0;
-  std::vector<T, Alloc> pPool;
+  Alloc pAlloc;
+  T* pData = nullptr;
 };
 }  // namespace PD

include/pd/drivers/drivers.hpp

@@ -1,3 +1,4 @@
 #pragma once
 
-#include <pd/drivers/os.hpp>
+#include <pd/drivers/os.hpp>
+#include <pd/drivers/gfx.hpp>

include/pd/drivers/gfx.hpp

@@ -22,25 +22,78 @@ enum class TextureFormat {
   A8,
 };
 
+// Pre interface class
 class PD_API GfxDriver : public DriverInterface {
  public:
-  GfxDriver(std::string_view name = "Default") : DriverInterface(name) {}
-  virtual ~GfxDriver() {}
+  GfxDriver(std::string_view name);
+  virtual ~GfxDriver() = default;
 
   virtual void Init() {}
-  virtual void Deinit() {}
-  virtual void Submit() {}
+
+  void SetViewPort(const ivec2& size);
+  void SetViewPort(int x, int y);
   virtual void BindTexture(TextureID id) {}
-  virtual void Reset() {}
+  void Reset();
   virtual TextureID LoadTexture(const std::vector<PD::u8>& pixels, int w, int h,
                                 TextureFormat type = TextureFormat::RGBA32,
-                                TextureFilter filter = TextureFilter::Linear) {}
+                                TextureFilter filter = TextureFilter::Linear) {
+    return 0;
+  }
   virtual void DeleteTexture(const TextureID& tex) {}
-  void Draw(const std::vector<Li::Command>& commands) {
+  virtual void Draw(const Pool<Li::Command>& commands) {}
+
+ protected:
+  virtual void SysDeinit() {}
+  virtual void SysInit() {}
+  virtual void SysReset() {}
+  virtual void Submit(size_t count, size_t start) {}
+  virtual void ResetPools() = 0;
+
+  // Counters
+  size_t CountDrawcalls = 0;
+  size_t CountCommands = 0;
+  size_t CountVertices = 0;
+  size_t CountIndices = 0;
+  size_t CurrentIndex = 0;
+  size_t CurrentVertex = 0;
+  TextureID CurrentTex = 0;
+  Mat4 Projection;
+  ivec2 ViewPort;
+};
+
+struct DefaultGfxConfig {
+  // Vertex Allocator
+  template <typename T>
+  using VertexAlloc = std::allocator<T>;
+  // Index Allocator
+  template <typename T>
+  using IndexAlloc = std::allocator<T>;
+  using IndexType = u16;  // Index Type
+
+  static constexpr size_t NumVertices = 32768;  // 8192*4
+  static constexpr size_t NumIndices = 49152;   // 8192*6
+};
+
+template <typename Config = DefaultGfxConfig>
+class PD_API GfxDriverBase : public GfxDriver {
+ public:
+  using IndexType = Config::IndexType;
+  using VtxPool =
+      Pool<Li::Vertex, typename Config::template VertexAlloc<Li::Vertex>>;
+  using IdxPool =
+      Pool<IndexType, typename Config::template VertexAlloc<IndexType>>;
+  GfxDriverBase(std::string_view name = "Default") : GfxDriver(name) {}
+  virtual ~GfxDriverBase() {}
+
+  void Init() override {
+    pVtxPool.Init(Config::NumVertices);
+    pIdxPool.Init(Config::NumIndices);
+    SysInit();
+  }
+
+  void Draw(const Pool<Li::Command>& commands) override {
     CountCommands += commands.size();
-    // Bind shader
     Projection = Mat4::Ortho(0.f, ViewPort.x, ViewPort.y, 0.f, 1.f, -1.f);
-    // Shader Set Mtx
     size_t index = 0;
     while (index < commands.size()) {
       CurrentTex = commands[index].Tex;
@@ -48,21 +101,36 @@ class PD_API GfxDriver : public DriverInterface {
         index++;
         continue;
       }
+      size_t startidx = CurrentIndex;
+      while (index < commands.size() && CurrentTex == commands[index].Tex) {
+        const auto& c = commands[index];
+        CountVertices += c.VertexCount;
+        CountIndices += c.IndexCount;
+        auto pIdx = pIdxPool.Allocate(c.IndexCount);
+        auto pVtx = pVtxPool.Allocate(c.VertexCount);
+        for (size_t i = 0; i < c.IndexCount; i++) {
+          pIdx[i] = CurrentVertex + c.FirstIndex[i];
+        }
+        for (size_t i = 0; i < c.VertexCount; i++) {
+          pVtx[i] = c.FirstVertex[i];
+        }
+        index++;
+      }
+      Submit(index - startidx, startidx);
     }
   }
 
- private:
-  size_t CurrentIndex = 0;
-  size_t CurrentVertex = 0;
-  TextureID CurrentTex = 0;
-  Mat4 Projection;
-  ivec2 ViewPort;
+ protected:
+  IndexType* GetIndexBufPtr(size_t start) { return &pIdxPool[start]; }
+  Li::Vertex* GetVertexBufPtr(size_t start) { return &pVtxPool[start]; }
+  void ResetPools() override {
+    pVtxPool.Reset();
+    pIdxPool.Reset();
+  }
 
-  // Counters
-  size_t CountDrawcalls = 0;
-  size_t CountCommands = 0;
-  size_t CountVertices = 0;
-  size_t CountIndices = 0;
+ private:
+  VtxPool pVtxPool;
+  IdxPool pIdxPool;
 };
 
 class PD_API Gfx {

source/drivers/gfx.cpp

@@ -0,0 +1,19 @@
+#include <pd/drivers/gfx.hpp>
+
+namespace PD {
+PD_API std::unique_ptr<GfxDriver> Gfx::driver;
+
+GfxDriver::GfxDriver(std::string_view name) : DriverInterface(name) {}
+
+void GfxDriver::SetViewPort(const ivec2& size) { ViewPort = size; }
+void GfxDriver::SetViewPort(int x, int y) {
+  ViewPort.x = x;
+  ViewPort.y = y;
+}
+
+void GfxDriver::Reset() {
+  CurrentVertex = 0;
+  CurrentIndex = 0;
+  SysReset();
+}
+}  // namespace PD

tests/core/source/main.cpp

@@ -24,5 +24,10 @@ int main() {
   PD::Os::UseDriver<PD::OsDriver>();
   ColorTests();
   std::cout << PD::Os::GetTime() << std::endl;
+  PD::Pool<int> pool;
+  pool.Init(90);
+  int* elems = pool.Allocate(5);
+  std::cout << std::format("Pool ({}/{})", pool.size(), pool.capacity())
+            << std::endl;
   return 0;
 }

vendor/CMakeLists.txt

@@ -0,0 +1,8 @@
+cmake_minimum_required(VERSION 3.22)
+
+# GLAD
+add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/glad)
+
+# STB
+add_library(stb INTERFACE)
+target_include_directories(stb INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/stb)

vendor/glad/CMakeLists.txt

@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 3.22)
+
+project(glad LANGUAGES C)
+
+add_library(glad STATIC
+    ${CMAKE_CURRENT_SOURCE_DIR}/src/glad.c
+)
+target_include_directories(glad
+    PUBLIC
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+    $<INSTALL_INTERFACE:include>
+)

vendor/glad/README.md

@@ -0,0 +1,7 @@
+# glad OpenGL Loader
+
+Generator command:
+
+```bash
+python3 -m glad --profile core --out-path glad/ --api gl=3.3 --generator=c
+```

vendor/glad/include/KHR/khrplatform.h

@@ -0,0 +1,311 @@
+#ifndef __khrplatform_h_
+#define __khrplatform_h_
+
+/*
+** Copyright (c) 2008-2018 The Khronos Group Inc.
+**
+** Permission is hereby granted, free of charge, to any person obtaining a
+** copy of this software and/or associated documentation files (the
+** "Materials"), to deal in the Materials without restriction, including
+** without limitation the rights to use, copy, modify, merge, publish,
+** distribute, sublicense, and/or sell copies of the Materials, and to
+** permit persons to whom the Materials are furnished to do so, subject to
+** the following conditions:
+**
+** The above copyright notice and this permission notice shall be included
+** in all copies or substantial portions of the Materials.
+**
+** THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+** EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+** MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+** IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+** CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+** TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+** MATERIALS OR THE USE OR OTHER DEALINGS IN THE MATERIALS.
+*/
+
+/* Khronos platform-specific types and definitions.
+ *
+ * The master copy of khrplatform.h is maintained in the Khronos EGL
+ * Registry repository at https://github.com/KhronosGroup/EGL-Registry
+ * The last semantic modification to khrplatform.h was at commit ID:
+ *      67a3e0864c2d75ea5287b9f3d2eb74a745936692
+ *
+ * Adopters may modify this file to suit their platform. Adopters are
+ * encouraged to submit platform specific modifications to the Khronos
+ * group so that they can be included in future versions of this file.
+ * Please submit changes by filing pull requests or issues on
+ * the EGL Registry repository linked above.
+ *
+ *
+ * See the Implementer's Guidelines for information about where this file
+ * should be located on your system and for more details of its use:
+ *    http://www.khronos.org/registry/implementers_guide.pdf
+ *
+ * This file should be included as
+ *        #include <KHR/khrplatform.h>
+ * by Khronos client API header files that use its types and defines.
+ *
+ * The types in khrplatform.h should only be used to define API-specific types.
+ *
+ * Types defined in khrplatform.h:
+ *    khronos_int8_t              signed   8  bit
+ *    khronos_uint8_t             unsigned 8  bit
+ *    khronos_int16_t             signed   16 bit
+ *    khronos_uint16_t            unsigned 16 bit
+ *    khronos_int32_t             signed   32 bit
+ *    khronos_uint32_t            unsigned 32 bit
+ *    khronos_int64_t             signed   64 bit
+ *    khronos_uint64_t            unsigned 64 bit
+ *    khronos_intptr_t            signed   same number of bits as a pointer
+ *    khronos_uintptr_t           unsigned same number of bits as a pointer
+ *    khronos_ssize_t             signed   size
+ *    khronos_usize_t             unsigned size
+ *    khronos_float_t             signed   32 bit floating point
+ *    khronos_time_ns_t           unsigned 64 bit time in nanoseconds
+ *    khronos_utime_nanoseconds_t unsigned time interval or absolute time in
+ *                                         nanoseconds
+ *    khronos_stime_nanoseconds_t signed time interval in nanoseconds
+ *    khronos_boolean_enum_t      enumerated boolean type. This should
+ *      only be used as a base type when a client API's boolean type is
+ *      an enum. Client APIs which use an integer or other type for
+ *      booleans cannot use this as the base type for their boolean.
+ *
+ * Tokens defined in khrplatform.h:
+ *
+ *    KHRONOS_FALSE, KHRONOS_TRUE Enumerated boolean false/true values.
+ *
+ *    KHRONOS_SUPPORT_INT64 is 1 if 64 bit integers are supported; otherwise 0.
+ *    KHRONOS_SUPPORT_FLOAT is 1 if floats are supported; otherwise 0.
+ *
+ * Calling convention macros defined in this file:
+ *    KHRONOS_APICALL
+ *    KHRONOS_APIENTRY
+ *    KHRONOS_APIATTRIBUTES
+ *
+ * These may be used in function prototypes as:
+ *
+ *      KHRONOS_APICALL void KHRONOS_APIENTRY funcname(
+ *                                  int arg1,
+ *                                  int arg2) KHRONOS_APIATTRIBUTES;
+ */
+
+#if defined(__SCITECH_SNAP__) && !defined(KHRONOS_STATIC)
+#   define KHRONOS_STATIC 1
+#endif
+
+/*-------------------------------------------------------------------------
+ * Definition of KHRONOS_APICALL
+ *-------------------------------------------------------------------------
+ * This precedes the return type of the function in the function prototype.
+ */
+#if defined(KHRONOS_STATIC)
+    /* If the preprocessor constant KHRONOS_STATIC is defined, make the
+     * header compatible with static linking. */
+#   define KHRONOS_APICALL
+#elif defined(_WIN32)
+#   define KHRONOS_APICALL __declspec(dllimport)
+#elif defined (__SYMBIAN32__)
+#   define KHRONOS_APICALL IMPORT_C
+#elif defined(__ANDROID__)
+#   define KHRONOS_APICALL __attribute__((visibility("default")))
+#else
+#   define KHRONOS_APICALL
+#endif
+
+/*-------------------------------------------------------------------------
+ * Definition of KHRONOS_APIENTRY
+ *-------------------------------------------------------------------------
+ * This follows the return type of the function  and precedes the function
+ * name in the function prototype.
+ */
+#if defined(_WIN32) && !defined(_WIN32_WCE) && !defined(__SCITECH_SNAP__)
+    /* Win32 but not WinCE */
+#   define KHRONOS_APIENTRY __stdcall
+#else
+#   define KHRONOS_APIENTRY
+#endif
+
+/*-------------------------------------------------------------------------
+ * Definition of KHRONOS_APIATTRIBUTES
+ *-------------------------------------------------------------------------
+ * This follows the closing parenthesis of the function prototype arguments.
+ */
+#if defined (__ARMCC_2__)
+#define KHRONOS_APIATTRIBUTES __softfp
+#else
+#define KHRONOS_APIATTRIBUTES
+#endif
+
+/*-------------------------------------------------------------------------
+ * basic type definitions
+ *-----------------------------------------------------------------------*/
+#if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) || defined(__GNUC__) || defined(__SCO__) || defined(__USLC__)
+
+
+/*
+ * Using <stdint.h>
+ */
+#include <stdint.h>
+typedef int32_t                 khronos_int32_t;
+typedef uint32_t                khronos_uint32_t;
+typedef int64_t                 khronos_int64_t;
+typedef uint64_t                khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+/*
+ * To support platform where unsigned long cannot be used interchangeably with
+ * inptr_t (e.g. CHERI-extended ISAs), we can use the stdint.h intptr_t.
+ * Ideally, we could just use (u)intptr_t everywhere, but this could result in
+ * ABI breakage if khronos_uintptr_t is changed from unsigned long to
+ * unsigned long long or similar (this results in different C++ name mangling).
+ * To avoid changes for existing platforms, we restrict usage of intptr_t to
+ * platforms where the size of a pointer is larger than the size of long.
+ */
+#if defined(__SIZEOF_LONG__) && defined(__SIZEOF_POINTER__)
+#if __SIZEOF_POINTER__ > __SIZEOF_LONG__
+#define KHRONOS_USE_INTPTR_T
+#endif
+#endif
+
+#elif defined(__VMS ) || defined(__sgi)
+
+/*
+ * Using <inttypes.h>
+ */
+#include <inttypes.h>
+typedef int32_t                 khronos_int32_t;
+typedef uint32_t                khronos_uint32_t;
+typedef int64_t                 khronos_int64_t;
+typedef uint64_t                khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#elif defined(_WIN32) && !defined(__SCITECH_SNAP__)
+
+/*
+ * Win32
+ */
+typedef __int32                 khronos_int32_t;
+typedef unsigned __int32        khronos_uint32_t;
+typedef __int64                 khronos_int64_t;
+typedef unsigned __int64        khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#elif defined(__sun__) || defined(__digital__)
+
+/*
+ * Sun or Digital
+ */
+typedef int                     khronos_int32_t;
+typedef unsigned int            khronos_uint32_t;
+#if defined(__arch64__) || defined(_LP64)
+typedef long int                khronos_int64_t;
+typedef unsigned long int       khronos_uint64_t;
+#else
+typedef long long int           khronos_int64_t;
+typedef unsigned long long int  khronos_uint64_t;
+#endif /* __arch64__ */
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#elif 0
+
+/*
+ * Hypothetical platform with no float or int64 support
+ */
+typedef int                     khronos_int32_t;
+typedef unsigned int            khronos_uint32_t;
+#define KHRONOS_SUPPORT_INT64   0
+#define KHRONOS_SUPPORT_FLOAT   0
+
+#else
+
+/*
+ * Generic fallback
+ */
+#include <stdint.h>
+typedef int32_t                 khronos_int32_t;
+typedef uint32_t                khronos_uint32_t;
+typedef int64_t                 khronos_int64_t;
+typedef uint64_t                khronos_uint64_t;
+#define KHRONOS_SUPPORT_INT64   1
+#define KHRONOS_SUPPORT_FLOAT   1
+
+#endif
+
+
+/*
+ * Types that are (so far) the same on all platforms
+ */
+typedef signed   char          khronos_int8_t;
+typedef unsigned char          khronos_uint8_t;
+typedef signed   short int     khronos_int16_t;
+typedef unsigned short int     khronos_uint16_t;
+
+/*
+ * Types that differ between LLP64 and LP64 architectures - in LLP64,
+ * pointers are 64 bits, but 'long' is still 32 bits. Win64 appears
+ * to be the only LLP64 architecture in current use.
+ */
+#ifdef KHRONOS_USE_INTPTR_T
+typedef intptr_t               khronos_intptr_t;
+typedef uintptr_t              khronos_uintptr_t;
+#elif defined(_WIN64)
+typedef signed   long long int khronos_intptr_t;
+typedef unsigned long long int khronos_uintptr_t;
+#else
+typedef signed   long  int     khronos_intptr_t;
+typedef unsigned long  int     khronos_uintptr_t;
+#endif
+
+#if defined(_WIN64)
+typedef signed   long long int khronos_ssize_t;
+typedef unsigned long long int khronos_usize_t;
+#else
+typedef signed   long  int     khronos_ssize_t;
+typedef unsigned long  int     khronos_usize_t;
+#endif
+
+#if KHRONOS_SUPPORT_FLOAT
+/*
+ * Float type
+ */
+typedef          float         khronos_float_t;
+#endif
+
+#if KHRONOS_SUPPORT_INT64
+/* Time types
+ *
+ * These types can be used to represent a time interval in nanoseconds or
+ * an absolute Unadjusted System Time.  Unadjusted System Time is the number
+ * of nanoseconds since some arbitrary system event (e.g. since the last
+ * time the system booted).  The Unadjusted System Time is an unsigned
+ * 64 bit value that wraps back to 0 every 584 years.  Time intervals
+ * may be either signed or unsigned.
+ */
+typedef khronos_uint64_t       khronos_utime_nanoseconds_t;
+typedef khronos_int64_t        khronos_stime_nanoseconds_t;
+#endif
+
+/*
+ * Dummy value used to pad enum types to 32 bits.
+ */
+#ifndef KHRONOS_MAX_ENUM
+#define KHRONOS_MAX_ENUM 0x7FFFFFFF
+#endif
+
+/*
+ * Enumerated boolean type
+ *
+ * Values other than zero should be considered to be true.  Therefore
+ * comparisons should not be made against KHRONOS_TRUE.
+ */
+typedef enum {
+    KHRONOS_FALSE = 0,
+    KHRONOS_TRUE  = 1,
+    KHRONOS_BOOLEAN_ENUM_FORCE_SIZE = KHRONOS_MAX_ENUM
+} khronos_boolean_enum_t;
+
+#endif /* __khrplatform_h_ */