src/starboard/examples/glclear/main.cc - cobalt - Git at Google

 // Copyright 2016 The Cobalt Authors. All Rights Reserved.
 //
 // 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 <math.h>

 #include <iomanip>

 #include "starboard/common/log.h"
 #include "starboard/event.h"
 #include "starboard/input.h"
 #include "starboard/memory.h"
 #include "starboard/system.h"
 #include "starboard/window.h"

 #if SB_API_VERSION < 11

 // This example uses the updated EGL and GLES Starboard interfaces implemented
 // in Staboard API version 11. These interfaces substantially changed how EGL
 // and GLES are used, and are not compatible with previous methodologies. For
 // additional information, please refer to the following files:
 //
 //   //starboard/egl.h
 //   //starboard/gles.h
 //
 //   //cobalt/renderer/egl_and_gles.h

 void SbEventHandle(const SbEvent* event) {
   SB_NOTREACHED() << "SB_API_VERSION must be >= 11.";
 }
 #else  // SB_API_VERSION >= 11

 #include "starboard/egl.h"
 #include "starboard/gles.h"

 #define EGL_CALL(x)                                                    \
   do {                                                                 \
     SbGetEglInterface()->x;                                            \
     SB_DCHECK((SbGetEglInterface()->eglGetError()) == SB_EGL_SUCCESS); \
   } while (false)

 #define EGL_CALL_SIMPLE(x) (SbGetEglInterface()->x)

 #define GL_CALL(x)                                                     \
   do {                                                                 \
     SbGetGlesInterface()->x;                                           \
     SB_DCHECK((SbGetGlesInterface()->glGetError()) == SB_GL_NO_ERROR); \
   } while (false)

 #define GL_CALL_SIMPLE(x) (SbGetGlesInterface()->x)

 namespace {

 SbEglInt32 const kAttributeList[] = {SB_EGL_RED_SIZE,
                                      8,
                                      SB_EGL_GREEN_SIZE,
                                      8,
                                      SB_EGL_BLUE_SIZE,
                                      8,
                                      SB_EGL_ALPHA_SIZE,
                                      8,
                                      SB_EGL_STENCIL_SIZE,
                                      0,
                                      SB_EGL_BUFFER_SIZE,
                                      32,
                                      SB_EGL_SURFACE_TYPE,
                                      SB_EGL_WINDOW_BIT | SB_EGL_PBUFFER_BIT,
                                      SB_EGL_COLOR_BUFFER_TYPE,
                                      SB_EGL_RGB_BUFFER,
                                      SB_EGL_CONFORMANT,
                                      SB_EGL_OPENGL_ES2_BIT,
                                      SB_EGL_RENDERABLE_TYPE,
                                      SB_EGL_OPENGL_ES2_BIT,
                                      SB_EGL_NONE};
 }  // namespace

 class Application {
  public:
   Application();
   ~Application();

  private:
   // The callback function passed to SbEventSchedule().  Its purpose is to
   // forward to the non-static RenderScene() method.
   static void RenderSceneEventCallback(void* param);

   // Renders one frame of the animated scene, incrementing |frame_| each time
   // it is called.
   void RenderScene();

   // The current frame we are rendering, initialized to 0 and incremented after
   // each frame.
   int frame_;

   // The SbWindow within which we will perform our rendering.
   SbWindow window_;

   SbEglDisplay display_;
   SbEglSurface surface_;
   SbEglContext context_;

   SbEglInt32 egl_surface_width_;
   SbEglInt32 egl_surface_height_;
 };

 Application::Application() {
   frame_ = 0;

   SbWindowOptions options;
   SbWindowSetDefaultOptions(&options);
   window_ = SbWindowCreate(&options);
   SB_CHECK(SbWindowIsValid(window_));

   display_ = EGL_CALL_SIMPLE(eglGetDisplay(SB_EGL_DEFAULT_DISPLAY));
   SB_CHECK(SB_EGL_SUCCESS == EGL_CALL_SIMPLE(eglGetError()));
   SB_CHECK(SB_EGL_NO_DISPLAY != display_);

   EGL_CALL(eglInitialize(display_, NULL, NULL));

   // Some EGL drivers can return a first config that doesn't allow
   // eglCreateWindowSurface(), with no differences in SbEglConfig attribute
   // values from configs that do allow that. To handle that, we have to attempt
   // eglCreateWindowSurface() until we find a config that succeeds.

   // First, query how many configs match the given attribute list.
   SbEglInt32 num_configs = 0;
   EGL_CALL(eglChooseConfig(display_, kAttributeList, NULL, 0, &num_configs));
   SB_CHECK(0 != num_configs);

   // Allocate space to receive the matching configs and retrieve them.
   SbEglConfig* configs = reinterpret_cast<SbEglConfig*>(
       SbMemoryAllocate(num_configs * sizeof(SbEglConfig)));
   EGL_CALL(eglChooseConfig(display_, kAttributeList, configs, num_configs,
                            &num_configs));

   SbEglNativeWindowType native_window =
       (SbEglNativeWindowType)SbWindowGetPlatformHandle(window_);
   SbEglConfig config;

   // Find the first config that successfully allow a window surface to be
   // created.
   for (int config_number = 0; config_number < num_configs; ++config_number) {
     config = configs[config_number];
     surface_ = EGL_CALL_SIMPLE(
         eglCreateWindowSurface(display_, config, native_window, NULL));
     if (SB_EGL_SUCCESS == EGL_CALL_SIMPLE(eglGetError()))
       break;
   }
   SB_DCHECK(surface_ != SB_EGL_NO_SURFACE);

   SbMemoryDeallocate(configs);

   EGL_CALL(
       eglQuerySurface(display_, surface_, SB_EGL_WIDTH, &egl_surface_width_));
   EGL_CALL(
       eglQuerySurface(display_, surface_, SB_EGL_HEIGHT, &egl_surface_height_));
   SB_DCHECK(egl_surface_width_ > 0);
   SB_DCHECK(egl_surface_height_ > 0);

   // Create the GLES2 or GLEX3 Context.
   context_ = SB_EGL_NO_CONTEXT;
   SbEglInt32 context_attrib_list[] = {
       SB_EGL_CONTEXT_CLIENT_VERSION, 3, SB_EGL_NONE,
   };
 #if SB_API_VERSION < 12 && defined(GLES3_SUPPORTED)
   // Attempt to create an OpenGL ES 3.0 context.
   context_ = EGL_CALL_SIMPLE(eglCreateContext(
       display_, config, SB_EGL_NO_CONTEXT, context_attrib_list));
 #endif
   if (context_ == SB_EGL_NO_CONTEXT) {
     // Create an OpenGL ES 2.0 context.
     context_attrib_list[1] = 2;
     context_ = EGL_CALL_SIMPLE(eglCreateContext(
         display_, config, SB_EGL_NO_CONTEXT, context_attrib_list));
   }
   SB_CHECK(SB_EGL_SUCCESS == EGL_CALL_SIMPLE(eglGetError()));
   SB_CHECK(context_ != SB_EGL_NO_CONTEXT);

   /* connect the context to the surface */
   EGL_CALL(eglMakeCurrent(display_, surface_, surface_, context_));

   RenderScene();
 }

 Application::~Application() {
   // Cleanup all used resources.
   EGL_CALL(eglMakeCurrent(display_, SB_EGL_NO_SURFACE, SB_EGL_NO_SURFACE,
                           SB_EGL_NO_CONTEXT));
   EGL_CALL(eglDestroyContext(display_, context_));
   EGL_CALL(eglDestroySurface(display_, surface_));
   EGL_CALL(eglTerminate(display_));
   SbWindowDestroy(window_);
 }

 void Application::RenderSceneEventCallback(void* param) {
   // Forward the call to the application instance specified as the parameter.
   Application* application = static_cast<Application*>(param);
   application->RenderScene();
 }

 namespace {

 float getIntensity(int frame, float rate) {
   float radian = 2 * M_PI * frame / rate;
   return 0.5 + 0.5 * sin(radian);
 }

 }  // namespace

 void Application::RenderScene() {
   // Render a moving and color changing rectangle using glClear() and
   // glScissor().
   GL_CALL_SIMPLE(glEnable(SB_GL_SCISSOR_TEST));

   float radian = 2 * M_PI * frame_ / 600.0f;
   int offset_x = egl_surface_height_ * sin(radian) / 3.6;
   int offset_y = egl_surface_height_ * cos(radian) / 3.6;

   int block_width = egl_surface_width_ / 16;
   int block_height = egl_surface_height_ / 9;

   int center_x = (egl_surface_width_ - block_width) / 2;
   int center_y = (egl_surface_height_ - block_height) / 2;

   GL_CALL(glScissor(center_x + offset_x, center_y + offset_y, block_width,
                     block_height));
   GL_CALL(glClearColor(getIntensity(frame_, 55.0f), getIntensity(frame_, 60.0f),
                        getIntensity(frame_, 62.5f), 1.0));
   GL_CALL(glClear(SB_GL_COLOR_BUFFER_BIT));
   GL_CALL(glFlush());
   EGL_CALL(eglSwapBuffers(display_, surface_));

   // Schedule another frame render ASAP.
   SbEventSchedule(&Application::RenderSceneEventCallback, this, 0);
   ++frame_;
 }

 Application* s_application = NULL;

 // Simple Starboard window event handling to kick off our color animating
 // application.
 void SbEventHandle(const SbEvent* event) {
   switch (event->type) {
     case kSbEventTypeStart: {
       // Create the application, after which it will use SbEventSchedule()
       // on itself to trigger a frame update until the application is
       // terminated.
       s_application = new Application();
     } break;

     case kSbEventTypeStop: {
       // Shutdown the application.
       delete s_application;
     } break;

     default: {}
   }
 }
 #endif  // SB_API_VERSION < 11
	// Copyright 2016 The Cobalt Authors. All Rights Reserved.
	//
	// 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 <math.h>

	#include <iomanip>

	#include "starboard/common/log.h"
	#include "starboard/event.h"
	#include "starboard/input.h"
	#include "starboard/memory.h"
	#include "starboard/system.h"
	#include "starboard/window.h"

	#if SB_API_VERSION < 11

	// This example uses the updated EGL and GLES Starboard interfaces implemented
	// in Staboard API version 11. These interfaces substantially changed how EGL
	// and GLES are used, and are not compatible with previous methodologies. For
	// additional information, please refer to the following files:
	//
	// //starboard/egl.h
	// //starboard/gles.h
	//
	// //cobalt/renderer/egl_and_gles.h

	void SbEventHandle(const SbEvent* event) {
	SB_NOTREACHED() << "SB_API_VERSION must be >= 11.";
	}
	#else // SB_API_VERSION >= 11

	#include "starboard/egl.h"
	#include "starboard/gles.h"

	#define EGL_CALL(x) \
	do { \
	SbGetEglInterface()->x; \
	SB_DCHECK((SbGetEglInterface()->eglGetError()) == SB_EGL_SUCCESS); \
	} while (false)

	#define EGL_CALL_SIMPLE(x) (SbGetEglInterface()->x)

	#define GL_CALL(x) \
	do { \
	SbGetGlesInterface()->x; \
	SB_DCHECK((SbGetGlesInterface()->glGetError()) == SB_GL_NO_ERROR); \
	} while (false)

	#define GL_CALL_SIMPLE(x) (SbGetGlesInterface()->x)

	namespace {

	SbEglInt32 const kAttributeList[] = {SB_EGL_RED_SIZE,
	8,
	SB_EGL_GREEN_SIZE,
	8,
	SB_EGL_BLUE_SIZE,
	8,
	SB_EGL_ALPHA_SIZE,
	8,
	SB_EGL_STENCIL_SIZE,
	0,
	SB_EGL_BUFFER_SIZE,
	32,
	SB_EGL_SURFACE_TYPE,
	SB_EGL_WINDOW_BIT \| SB_EGL_PBUFFER_BIT,
	SB_EGL_COLOR_BUFFER_TYPE,
	SB_EGL_RGB_BUFFER,
	SB_EGL_CONFORMANT,
	SB_EGL_OPENGL_ES2_BIT,
	SB_EGL_RENDERABLE_TYPE,
	SB_EGL_OPENGL_ES2_BIT,
	SB_EGL_NONE};
	} // namespace

	class Application {
	public:
	Application();
	~Application();

	private:
	// The callback function passed to SbEventSchedule(). Its purpose is to
	// forward to the non-static RenderScene() method.
	static void RenderSceneEventCallback(void* param);

	// Renders one frame of the animated scene, incrementing \|frame_\| each time
	// it is called.
	void RenderScene();

	// The current frame we are rendering, initialized to 0 and incremented after
	// each frame.
	int frame_;

	// The SbWindow within which we will perform our rendering.
	SbWindow window_;

	SbEglDisplay display_;
	SbEglSurface surface_;
	SbEglContext context_;

	SbEglInt32 egl_surface_width_;
	SbEglInt32 egl_surface_height_;
	};

	Application::Application() {
	frame_ = 0;

	SbWindowOptions options;
	SbWindowSetDefaultOptions(&options);
	window_ = SbWindowCreate(&options);
	SB_CHECK(SbWindowIsValid(window_));

	display_ = EGL_CALL_SIMPLE(eglGetDisplay(SB_EGL_DEFAULT_DISPLAY));
	SB_CHECK(SB_EGL_SUCCESS == EGL_CALL_SIMPLE(eglGetError()));
	SB_CHECK(SB_EGL_NO_DISPLAY != display_);

	EGL_CALL(eglInitialize(display_, NULL, NULL));

	// Some EGL drivers can return a first config that doesn't allow
	// eglCreateWindowSurface(), with no differences in SbEglConfig attribute
	// values from configs that do allow that. To handle that, we have to attempt
	// eglCreateWindowSurface() until we find a config that succeeds.

	// First, query how many configs match the given attribute list.
	SbEglInt32 num_configs = 0;
	EGL_CALL(eglChooseConfig(display_, kAttributeList, NULL, 0, &num_configs));
	SB_CHECK(0 != num_configs);

	// Allocate space to receive the matching configs and retrieve them.
	SbEglConfig* configs = reinterpret_cast<SbEglConfig*>(
	SbMemoryAllocate(num_configs * sizeof(SbEglConfig)));
	EGL_CALL(eglChooseConfig(display_, kAttributeList, configs, num_configs,
	&num_configs));

	SbEglNativeWindowType native_window =
	(SbEglNativeWindowType)SbWindowGetPlatformHandle(window_);
	SbEglConfig config;

	// Find the first config that successfully allow a window surface to be
	// created.
	for (int config_number = 0; config_number < num_configs; ++config_number) {
	config = configs[config_number];
	surface_ = EGL_CALL_SIMPLE(
	eglCreateWindowSurface(display_, config, native_window, NULL));
	if (SB_EGL_SUCCESS == EGL_CALL_SIMPLE(eglGetError()))
	break;
	}
	SB_DCHECK(surface_ != SB_EGL_NO_SURFACE);

	SbMemoryDeallocate(configs);

	EGL_CALL(
	eglQuerySurface(display_, surface_, SB_EGL_WIDTH, &egl_surface_width_));
	EGL_CALL(
	eglQuerySurface(display_, surface_, SB_EGL_HEIGHT, &egl_surface_height_));
	SB_DCHECK(egl_surface_width_ > 0);
	SB_DCHECK(egl_surface_height_ > 0);

	// Create the GLES2 or GLEX3 Context.
	context_ = SB_EGL_NO_CONTEXT;
	SbEglInt32 context_attrib_list[] = {
	SB_EGL_CONTEXT_CLIENT_VERSION, 3, SB_EGL_NONE,
	};
	#if SB_API_VERSION < 12 && defined(GLES3_SUPPORTED)
	// Attempt to create an OpenGL ES 3.0 context.
	context_ = EGL_CALL_SIMPLE(eglCreateContext(
	display_, config, SB_EGL_NO_CONTEXT, context_attrib_list));
	#endif
	if (context_ == SB_EGL_NO_CONTEXT) {
	// Create an OpenGL ES 2.0 context.
	context_attrib_list[1] = 2;
	context_ = EGL_CALL_SIMPLE(eglCreateContext(
	display_, config, SB_EGL_NO_CONTEXT, context_attrib_list));
	}
	SB_CHECK(SB_EGL_SUCCESS == EGL_CALL_SIMPLE(eglGetError()));
	SB_CHECK(context_ != SB_EGL_NO_CONTEXT);

	/* connect the context to the surface */
	EGL_CALL(eglMakeCurrent(display_, surface_, surface_, context_));

	RenderScene();
	}

	Application::~Application() {
	// Cleanup all used resources.
	EGL_CALL(eglMakeCurrent(display_, SB_EGL_NO_SURFACE, SB_EGL_NO_SURFACE,
	SB_EGL_NO_CONTEXT));
	EGL_CALL(eglDestroyContext(display_, context_));
	EGL_CALL(eglDestroySurface(display_, surface_));
	EGL_CALL(eglTerminate(display_));
	SbWindowDestroy(window_);
	}

	void Application::RenderSceneEventCallback(void* param) {
	// Forward the call to the application instance specified as the parameter.
	Application* application = static_cast<Application*>(param);
	application->RenderScene();
	}

	namespace {

	float getIntensity(int frame, float rate) {
	float radian = 2 * M_PI * frame / rate;
	return 0.5 + 0.5 * sin(radian);
	}

	} // namespace

	void Application::RenderScene() {
	// Render a moving and color changing rectangle using glClear() and
	// glScissor().
	GL_CALL_SIMPLE(glEnable(SB_GL_SCISSOR_TEST));

	float radian = 2 * M_PI * frame_ / 600.0f;
	int offset_x = egl_surface_height_ * sin(radian) / 3.6;
	int offset_y = egl_surface_height_ * cos(radian) / 3.6;

	int block_width = egl_surface_width_ / 16;
	int block_height = egl_surface_height_ / 9;

	int center_x = (egl_surface_width_ - block_width) / 2;
	int center_y = (egl_surface_height_ - block_height) / 2;

	GL_CALL(glScissor(center_x + offset_x, center_y + offset_y, block_width,
	block_height));
	GL_CALL(glClearColor(getIntensity(frame_, 55.0f), getIntensity(frame_, 60.0f),
	getIntensity(frame_, 62.5f), 1.0));
	GL_CALL(glClear(SB_GL_COLOR_BUFFER_BIT));
	GL_CALL(glFlush());
	EGL_CALL(eglSwapBuffers(display_, surface_));

	// Schedule another frame render ASAP.
	SbEventSchedule(&Application::RenderSceneEventCallback, this, 0);
	++frame_;
	}

	Application* s_application = NULL;

	// Simple Starboard window event handling to kick off our color animating
	// application.
	void SbEventHandle(const SbEvent* event) {
	switch (event->type) {
	case kSbEventTypeStart: {
	// Create the application, after which it will use SbEventSchedule()
	// on itself to trigger a frame update until the application is
	// terminated.
	s_application = new Application();
	} break;

	case kSbEventTypeStop: {
	// Shutdown the application.
	delete s_application;
	} break;

	default: {}
	}
	}
	#endif // SB_API_VERSION < 11