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 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #ifndef WEBGLTYPES_H_

 #define WEBGLTYPES_H_

 #include "mozilla/TypedEnum.h"

 // Most WebIDL typedefs are identical to their OpenGL counterparts.

 #include "GLTypes.h"

 // Manual reflection of WebIDL typedefs that are different from their

 // OpenGL counterparts.

 typedef int64_t WebGLsizeiptr;

 typedef int64_t WebGLintptr;

 typedef bool WebGLboolean;

 namespace mozilla {

 /*

  * WebGLContextFakeBlackStatus and WebGLTextureFakeBlackStatus are enums to

  * track what needs to use a dummy 1x1 black texture, which we refer to as a

  * 'fake black' texture.

  *

  * There are generally two things that can cause us to use such 'fake black'

  * textures:

  *

  *   (1) OpenGL ES rules on sampling incomplete textures specify that they

  *       must be sampled as RGBA(0, 0, 0, 1) (opaque black). We have to implement these rules

  *       ourselves, if only because we do not always run on OpenGL ES, and also

  *       because this is dangerously close to the kind of case where we don't

  *       want to trust the driver with corner cases of texture memory accesses.

  *

  *   (2) OpenGL has cases where a renderbuffer, or a texture image, can contain

  *       uninitialized image data. See below the comment about WebGLImageDataStatus.

  *       WebGL must never have access to uninitialized image data. The WebGL 1 spec,

  *       section 4.1 'Resource Restrictions', specifies that in any such case, the

  *       uninitialized image data must be exposed to WebGL as if it were filled

  *       with zero bytes, which means it's either opaque or transparent black

  *       depending on whether the image format has alpha.

  *

  * Why are there _two_ separate enums there, WebGLContextFakeBlackStatus

  * and WebGLTextureFakeBlackStatus? That's because each texture must know the precise

  * reason why it needs to be faked (incomplete texture vs. uninitialized image data),

  * whereas the WebGL context can only know whether _any_ faking is currently needed at all.

  */

 MOZ_BEGIN_ENUM_CLASS(WebGLContextFakeBlackStatus, int)

   Unknown,

   NotNeeded,

   Needed

 MOZ_END_ENUM_CLASS(WebGLContextFakeBlackStatus)

 MOZ_BEGIN_ENUM_CLASS(WebGLTextureFakeBlackStatus, int)

   Unknown,

   NotNeeded,

   IncompleteTexture,

   UninitializedImageData

 MOZ_END_ENUM_CLASS(WebGLTextureFakeBlackStatus)

 /*

  * Implementing WebGL (or OpenGL ES 2.0) on top of desktop OpenGL requires

  * emulating the vertex attrib 0 array when it's not enabled. Indeed,

  * OpenGL ES 2.0 allows drawing without vertex attrib 0 array enabled, but

  * desktop OpenGL does not allow that.

  */

 MOZ_BEGIN_ENUM_CLASS(WebGLVertexAttrib0Status, int)

     Default, // default status - no emulation needed

     EmulatedUninitializedArray, // need an artificial attrib 0 array, but contents may be left uninitialized

     EmulatedInitializedArray // need an artificial attrib 0 array, and contents must be initialized

 MOZ_END_ENUM_CLASS(WebGLVertexAttrib0Status)

 /*

  * Enum to track the status of image data (renderbuffer or texture image) presence

  * and initialization.

  *

  * - NoImageData is the initial state before any image data is allocated.

  * - InitializedImageData is the state after image data is allocated and initialized.

  * - UninitializedImageData is an intermediate state where data is allocated but not

  *   initialized. It is the state that renderbuffers are in after a renderbufferStorage call,

  *   and it is the state that texture images are in after a texImage2D call with null data.

  */

 MOZ_BEGIN_ENUM_CLASS(WebGLImageDataStatus, int)

     NoImageData,

     UninitializedImageData,

     InitializedImageData

 MOZ_END_ENUM_CLASS(WebGLImageDataStatus)

 /*

  * The formats that may participate, either as source or destination formats,

  * in WebGL texture conversions. This includes:

  *  - all the formats accepted by WebGL.texImage2D, e.g. RGBA4444

  *  - additional formats provided by extensions, e.g. RGB32F

  *  - additional source formats, depending on browser details, used when uploading

  *    textures from DOM elements. See gfxImageSurface::Format().

  */

 MOZ_BEGIN_ENUM_CLASS(WebGLTexelFormat, int)

     // returned by SurfaceFromElementResultToImageSurface to indicate absence of image data

     None,

     // dummy error code returned by GetWebGLTexelFormat in error cases,

     // after assertion failure (so this never happens in debug builds)

     BadFormat,

     // dummy pseudo-format meaning "use the other format".

     // For example, if SrcFormat=Auto and DstFormat=RGB8, then the source

     // is implicitly treated as being RGB8 itself.

     Auto,

     // 1-channel formats

     R8,

     A8,

     D16, // WEBGL_depth_texture

     D32, // WEBGL_depth_texture

     R16F, // OES_texture_half_float

     A16F, // OES_texture_half_float

     R32F, // OES_texture_float

     A32F, // OES_texture_float

     // 2-channel formats

     RA8,

     RA16F, // OES_texture_half_float

     RA32F, // OES_texture_float

     D24S8, // WEBGL_depth_texture

     // 3-channel formats

     RGB8,

     BGRX8, // used for DOM elements. Source format only.

     RGB565,

     RGB16F, // OES_texture_half_float

     RGB32F, // OES_texture_float

     // 4-channel formats

     RGBA8,

     BGRA8, // used for DOM elements

     RGBA5551,

     RGBA4444,

     RGBA16F, // OES_texture_half_float

     RGBA32F // OES_texture_float

 MOZ_END_ENUM_CLASS(WebGLTexelFormat)

 MOZ_BEGIN_ENUM_CLASS(WebGLTexImageFunc, int)

     TexImage,

     TexSubImage,

     CopyTexImage,

     CopyTexSubImage,

     CompTexImage,

     CompTexSubImage,

 MOZ_END_ENUM_CLASS(WebGLTexImageFunc)

 // Please keep extensions in alphabetic order.

 MOZ_BEGIN_ENUM_CLASS(WebGLExtensionID, uint8_t)

     ANGLE_instanced_arrays,

     EXT_color_buffer_half_float,

     EXT_frag_depth,

     EXT_sRGB,

     EXT_texture_filter_anisotropic,

     OES_element_index_uint,

     OES_standard_derivatives,

     OES_texture_float,

     OES_texture_float_linear,

     OES_texture_half_float,

     OES_texture_half_float_linear,

     OES_vertex_array_object,

     WEBGL_color_buffer_float,

     WEBGL_compressed_texture_atc,

     WEBGL_compressed_texture_etc1,

     WEBGL_compressed_texture_pvrtc,

     WEBGL_compressed_texture_s3tc,

     WEBGL_debug_renderer_info,

     WEBGL_debug_shaders,

     WEBGL_depth_texture,

     WEBGL_draw_buffers,

     WEBGL_lose_context,

     Max,

     Unknown

 MOZ_END_ENUM_CLASS(WebGLExtensionID)

 } // namespace mozilla

 #endif