Android rayshader sample.

samples/android_sample/jni/graphics.cc

+#include "graphics.h"
+#include <GLES2/gl2.h>
+#include <GLES2/gl2ext.h>
+
+Graphics::Graphics(android_app* pApplication, Timer* pTimer) :
+  mApplication(pApplication),
+  mTimer(pTimer),
+  mWidth(0),
+  mHeight(0),
+  mDisplay(EGL_NO_DISPLAY),
+  mSurface(EGL_NO_SURFACE),
+  mContext(EGL_NO_CONTEXT) {
+}
+
+const int32_t& Graphics::getHeight() {
+  return mHeight;
+}
+
+const int32_t& Graphics::getWidth() {
+  return mWidth;
+}
+
+int32_t Graphics::start() {
+  EGLint format, numConfigs, errorResult;
+  EGLConfig config;
+  const EGLint attributes[] = {
+      EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
+      //EGL_BLUE_SIZE, 5,
+      //EGL_GREEN_SIZE, 6,
+      //EGL_RED_SIZE, 5,
+      //EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+      EGL_NONE
+  };
+  static const EGLint ctx_attribs[] = {
+    EGL_CONTEXT_CLIENT_VERSION, 2,
+    EGL_NONE
+  };
+
+  mDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
+  if (mDisplay != EGL_NO_DISPLAY) {
+    Log::Print("eglInitialize");
+    if (eglInitialize(mDisplay, NULL, NULL)) {
+      Log::Print("eglChooseConfig");
+      if (eglChooseConfig(mDisplay, attributes, &config, 1, &numConfigs) &&
+          numConfigs > 0) {
+        Log::Print("eglGetConfigAttrib");
+        if (eglGetConfigAttrib(mDisplay, config,
+                               EGL_NATIVE_VISUAL_ID, &format)) {
+          ANativeWindow_setBuffersGeometry(mApplication->window, 0, 0, format);
+          mSurface = eglCreateWindowSurface(mDisplay, config,
+                              (EGLNativeWindowType)mApplication->window, NULL);
+          if (mSurface != EGL_NO_SURFACE) {
+            Log::Print("eglCreateContext");
+            mContext = eglCreateContext(mDisplay, config, EGL_NO_CONTEXT,
+                                        ctx_attribs);
+            if (mContext != EGL_NO_CONTEXT) {
+              if (eglMakeCurrent(mDisplay, mSurface, mSurface, mContext) &&
+                  eglQuerySurface(mDisplay, mSurface, EGL_WIDTH, &mWidth) &&
+                  mWidth > 0 &&
+                  eglQuerySurface(mDisplay, mSurface, EGL_HEIGHT, &mHeight) &&
+                  mHeight > 0) {
+                glViewport(0, 0, mWidth, mHeight);
+                return 0;
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+  Log::PrintErr("Error starting graphics");
+  stop();
+  return -1;
+}
+
+void Graphics::stop() {
+  Log::Print("Stopping graphics");
+  if (mDisplay != EGL_NO_DISPLAY) {
+    eglMakeCurrent(mDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+    if (mContext != EGL_NO_CONTEXT) {
+      eglDestroyContext(mDisplay, mContext);
+      mContext = EGL_NO_CONTEXT;
+    }
+    if (mSurface != EGL_NO_SURFACE) {
+      eglDestroySurface(mDisplay, mSurface);
+      mSurface = EGL_NO_SURFACE;
+    }
+    eglTerminate(mDisplay);
+    mDisplay = EGL_NO_DISPLAY;
+  }
+}
+
+int32_t Graphics::update() {
+  return 0;
+  /*
+  if (eglSwapBuffers(mDisplay, mSurface) != EGL_TRUE) {
+    Log::PrintErr("Error %d swapping buffers.", eglGetError());
+    return -1;
+  }
+  return 0;
+  */
+}