/* Copyright (c) 2011 The Chromium Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#ifndef PPAPI_C_PPB_GRAPHICS_3D_H_
#define PPAPI_C_PPB_GRAPHICS_3D_H_

#include "ppapi/c/pp_graphics_3d.h"

#include "ppapi/c/pp_bool.h"
#include "ppapi/c/pp_instance.h"
#include "ppapi/c/pp_resource.h"

// Example usage from plugin code:
//
// // Setup.
// PP_Resource context;
// int32_t attribs[] = {PP_GRAPHICS3DATTRIB_WIDTH, 800,
//                      PP_GRAPHICS3DATTRIB_HEIGHT, 800,
//                      PP_GRAPHICS3DATTRIB_NONE};
// context = g3d->Create(instance, attribs, &context);
// inst->BindGraphics(instance, context);
//
// // Present one frame.
// gles2->Clear(context, GL_COLOR_BUFFER);
// g3d->SwapBuffers(context);
//
// // Shutdown.
// core->ReleaseResource(context);

#define PPB_GRAPHICS_3D_INTERFACE_1_0 "PPB_Graphics3D;1.0"
#define PPB_GRAPHICS_3D_INTERFACE PPB_GRAPHICS_3D_INTERFACE_1_0

struct PPB_Graphics3D {
  // Retrieves the maximum supported value for the given attribute.
  //
  // This function may be used to check if a particular attribute value is
  // supported before attempting to create a context.
  // Attributes that can be queried for include:
  // - PP_GRAPHICS3DATTRIB_ALPHA_SIZE
  // - PP_GRAPHICS3DATTRIB_BLUE_SIZE
  // - PP_GRAPHICS3DATTRIB_GREEN_SIZE
  // - PP_GRAPHICS3DATTRIB_RED_SIZE
  // - PP_GRAPHICS3DATTRIB_DEPTH_SIZE
  // - PP_GRAPHICS3DATTRIB_STENCIL_SIZE
  // - PP_GRAPHICS3DATTRIB_SAMPLES
  // - PP_GRAPHICS3DATTRIB_SAMPLE_BUFFERS
  // - PP_GRAPHICS3DATTRIB_WIDTH
  // - PP_GRAPHICS3DATTRIB_HEIGHT
  //
  // On failure the following error codes may be returned:
  // - PP_ERROR_BADRESOURCE if instance is invalid.
  // - PP_ERROR_BADARGUMENT if attribute is invalid or value is NULL
  int32_t (*GetAttribMaxValue)(PP_Resource instance,
                               int32_t attribute, int32_t* value);

  // Creates and initializes a rendering context and returns a handle to it.
  // The returned context is off-screen to start with. It must be attached to
  // a plugin instance using PPB_Instance::BindGraphics to draw on the web page.
  //
  // If share_context is not NULL, then all shareable data, as defined
  // by the client API (note that for OpenGL and OpenGL ES, shareable data
  // excludes texture objects named 0) will be shared by share_context, all
  // other contexts share_context already shares with, and the newly created
  // context. An arbitrary number of PPB_Graphics3D_Dev can share data in
  // this fashion.
  //
  // attrib_list specifies a list of attributes for the context. It is a list
  // of attribute name-value pairs in which each attribute is immediately
  // followed by the corresponding desired value. The list is terminated with
  // PP_GRAPHICS3DATTRIB_NONE. The attrib_list may be NULL or empty
  // (first attribute is PP_GRAPHICS3DATTRIB_NONE). If an attribute is not
  // specified in attrib_list, then the default value is used (it is said to
  // be specified implicitly).
  //
  // Attributes for the context are chosen according to an attribute-specific
  // criteria. Attributes can be classified into two categories:
  // - AtLeast: The attribute value in the returned context meets or exceeds
  //            the value specified in attrib_list.
  // - Exact: The attribute value in the returned context is equal to
  //          the value specified in attrib_list.
  //
  // Attributes that can be specified in attrib_list include:
  // - PP_GRAPHICS3DATTRIB_ALPHA_SIZE: Category: AtLeast Default: 0.
  // - PP_GRAPHICS3DATTRIB_BLUE_SIZE: Category: AtLeast Default: 0.
  // - PP_GRAPHICS3DATTRIB_GREEN_SIZE: Category: AtLeast Default: 0.
  // - PP_GRAPHICS3DATTRIB_RED_SIZE: Category: AtLeast Default: 0.
  // - PP_GRAPHICS3DATTRIB_DEPTH_SIZE: Category: AtLeast Default: 0.
  // - PP_GRAPHICS3DATTRIB_STENCIL_SIZE: Category: AtLeast Default: 0.
  // - PP_GRAPHICS3DATTRIB_SAMPLES: Category: AtLeast Default: 0.
  // - PP_GRAPHICS3DATTRIB_SAMPLE_BUFFERS: Category: AtLeast Default: 0.
  // - PP_GRAPHICS3DATTRIB_WIDTH: Category: Exact Default: 0.
  // - PP_GRAPHICS3DATTRIB_HEIGHT: Category: Exact Default: 0.
  // - PP_GRAPHICS3DATTRIB_SWAP_BEHAVIOR:
  //   Category: Exact Default: Implementation defined.
  //
  // On failure NULL resource is returned.
  PP_Resource (*Create)(PP_Instance instance,
                        PP_Resource share_context,
                        const int32_t* attrib_list);

  // Returns PP_TRUE if the given resource is a valid PPB_Graphics3D_Dev,
  // PP_FALSE if it is an invalid resource or is a resource of another type.
  PP_Bool (*IsGraphics3D)(PP_Resource resource);

  // Retrieves the value for each attribute in attrib_list. The list
  // has the same structure as described for PPB_Graphics3D_Dev::Create.
  // It is both input and output structure for this function.
  //
  // All attributes specified in PPB_Graphics3D_Dev::Create can be queried for.
  // On failure the following error codes may be returned:
  // - PP_ERROR_BADRESOURCE if context is invalid.
  // - PP_ERROR_BADARGUMENT if attrib_list is NULL or any attribute in the
  //   attrib_list is not a valid attribute.
  //
  // Example usage: To get the values for rgb bits in the color buffer,
  // this function must be called as following:
  // int attrib_list[] = {PP_GRAPHICS3DATTRIB_RED_SIZE, 0,
  //                      PP_GRAPHICS3DATTRIB_GREEN_SIZE, 0,
  //                      PP_GRAPHICS3DATTRIB_BLUE_SIZE, 0,
  //                      PP_GRAPHICS3DATTRIB_NONE};
  // GetAttribs(context, attrib_list);
  // int red_bits = attrib_list[1];
  // int green_bits = attrib_list[3];
  // int blue_bits = attrib_list[5];
  int32_t (*GetAttribs)(PP_Resource context, int32_t* attrib_list);

  // Sets the values for each attribute in attrib_list. The list
  // has the same structure as described for PPB_Graphics3D_Dev::Create.
  //
  // Attributes that can be specified are:
  // - PP_GRAPHICS3DATTRIB_SWAP_BEHAVIOR
  //
  // On failure the following error codes may be returned:
  // - PP_ERROR_BADRESOURCE if context is invalid.
  // - PP_ERROR_BADARGUMENT if attrib_list is NULL or any attribute in the
  //   attrib_list is not a valid attribute.
  int32_t (*SetAttribs)(PP_Resource context, int32_t* attrib_list);

  // The recoverable error conditions that have no side effect are
  // detected and returned immediately by all functions in this interface.
  // In addition the implementation may get into a fatal state while
  // processing a command. In this case the application must detroy the
  // context and reinitialize client API state and objects to continue
  // rendering.
  //
  // Note that the same error code is also returned in the SwapBuffers callback.
  // It is recommended to handle error in the SwapBuffers callback because
  // GetError is synchronous. This function may be useful in rare cases where
  // drawing a frame is expensive and you want to verify the result of
  // ResizeBuffers before attemptimg to draw a frame.
  //
  // The following error codes may be returned:
  // - PP_ERROR_NOMEMORY
  // - PP_ERROR_CONTEXT_LOST
  int32_t (*GetError)(PP_Resource context);

  // Resizes the backing surface for context.
  //
  // On failure the following error codes may be returned:
  // - PP_ERROR_BADRESOURCE if context is invalid.
  // - PP_ERROR_BADARGUMENT if the value specified for width or height
  //   is less than zero.
  //
  // If the surface could not be resized due to insufficient resources,
  // PP_ERROR_NOMEMORY error is returned on the next SwapBuffers callback.
  int32_t (*ResizeBuffers)(PP_Resource context,
                           int32_t width, int32_t height);

  // Makes the contents of the color buffer available for compositing.
  // This function has no effect on off-screen surfaces - ones not bound
  // to any plugin instance. The contents of ancillary buffers are always
  // undefined after calling SwapBuffers. The contents of the color buffer are
  // undefined if the value of the PP_GRAPHICS3DATTRIB_SWAP_BEHAVIOR attribute
  // of context is not PP_GRAPHICS3DATTRIB_BUFFER_PRESERVED.
  //
  // SwapBuffers runs in asynchronous mode. Specify a callback function and the
  // argument for that callback function. The callback function will be executed
  // on the calling thread after the color buffer has been composited with
  // rest of the html page. While you are waiting for a SwapBuffers callback,
  // additional calls to SwapBuffers will fail.
  //
  // Because the callback is executed (or thread unblocked) only when the
  // plugin's current state is actually on the screen, this function provides a
  // way to rate limit animations. By waiting until the image is on the screen
  // before painting the next frame, you can ensure you're not generating
  // updates faster than the screen can be updated.
  //
  // SwapBuffers performs an implicit flush operation on context.
  // If the context gets into an unrecoverable error condition while
  // processing a command, the error code will be returned as the argument
  // for the callback. The callback may return the following error codes:
  // - PP_ERROR_NOMEMORY
  // - PP_ERROR_CONTEXT_LOST
  // Note that the same error code may also be obtained by calling GetError.
  //
  // On failure SwapBuffers may return the following error codes:
  // - PP_ERROR_BADRESOURCE if context is invalid.
  // - PP_ERROR_BADARGUMENT if callback is invalid.
  int32_t (*SwapBuffers)(PP_Resource context,
                         struct PP_CompletionCallback callback);
};

#endif  /* PPAPI_C_PPB_GRAPHICS_3D_H_ */