010d16f647
This makes it possible to integrate existing GLES2 code with applications using Cogl as the rendering api. Currently all GLES2 usage is handled with separate GLES2 contexts to ensure that GLES2 api usage doesn't interfere with Cogl's own use of OpenGL[ES]. The api has been designed though so we can provide tighter integration later. The api would allow us to support GLES2 virtualized on top of an OpenGL/GLX driver as well as GLES2 virtualized on the core rendering api of Cogl itself. Virtualizing the GLES2 support on Cogl will allow us to take advantage of Cogl debugging facilities as well as let us optimize the cost of allocating multiple GLES2 contexts and switching between them which can both be very expensive with many drivers. As as a side effect of this patch Cogl can also now be used as a portable window system binding API for GLES2 as an alternative to EGL. Parts of this patch are based on work done by Tomeu Vizoso <tomeu.vizoso@collabora.com> who did the first iteration of adding GLES2 API support to Cogl so that WebGL support could be added to webkit-clutter. This patch adds a very minimal cogl-gles2-context example that shows how to create a gles2 context, clear the screen to a random color and also draw a triangle with the cogl api. Reviewed-by: Neil Roberts <neil@linux.intel.com> (cherry picked from commit 4bb6eff3dbd50d8fef7d6bdbed55c5aaa70036a8)
369 lines
12 KiB
C
369 lines
12 KiB
C
/*
|
|
* Cogl
|
|
*
|
|
* An object oriented GL/GLES Abstraction/Utility Layer
|
|
*
|
|
* Copyright (C) 2011 Collabora Ltd.
|
|
* Copyright (C) 2012 Intel Corporation.
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2 of the License, or (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library. If not, see
|
|
* <http://www.gnu.org/licenses/>.
|
|
*
|
|
* Authors:
|
|
* Tomeu Vizoso <tomeu.vizoso@collabora.com>
|
|
* Robert Bragg <robert@linux.intel.com>
|
|
*
|
|
*/
|
|
|
|
#ifndef __COGL_GLES2_H__
|
|
#define __COGL_GLES2_H__
|
|
|
|
#define __COGL_H_INSIDE__
|
|
#include <cogl/cogl-defines.h>
|
|
#include <cogl/cogl-context.h>
|
|
#include <cogl/cogl-framebuffer.h>
|
|
#include <cogl/cogl-texture.h>
|
|
#include <cogl/cogl-texture-2d.h>
|
|
|
|
/* CoglGLES2Vtable depends on GLES 2.0 typedefs being available but we
|
|
* want to be careful that the public api doesn't expose arbitrary
|
|
* system GL headers as part of the Cogl API so although when building
|
|
* internally we consistently refer to the system headers to avoid
|
|
* conflicts we only expose the minimal set of GLES 2.0 types and enums
|
|
* publicly.
|
|
*/
|
|
#ifdef CLUTTER_COMPILATION
|
|
#include "cogl-gl-header.h"
|
|
#else
|
|
#include <cogl/cogl-gles2-types.h>
|
|
#endif
|
|
|
|
G_BEGIN_DECLS
|
|
|
|
/**
|
|
* SECTION:cogl-gles2
|
|
* @short_description: A portable api to access OpenGLES 2.0
|
|
*
|
|
* Cogl provides portable access to the OpenGLES api through a single
|
|
* library that is able to smooth over inconsistencies between the
|
|
* different vendor drivers for OpenGLES in a single place.
|
|
*
|
|
* The api is designed to allow Cogl to transparently implement the
|
|
* api on top of other drivers, such as OpenGL, D3D or on Cogl's own
|
|
* drawing api so even if your platform doesn't come with an
|
|
* OpenGLES 2.0 api Cogl may still be able to expose the api to your
|
|
* application.
|
|
*
|
|
* Since Cogl is a library and not an api specification it is possible
|
|
* to add OpenGLES 2.0 api features to Cogl which can immidiately
|
|
* benefit developers regardless of what platform they are running on.
|
|
*
|
|
* With this api it's possible to re-use existing OpenGLES 2.0 code
|
|
* within applications that are rendering with the Cogl API and also
|
|
* it's possible for applications that render using OpenGLES 2.0 to
|
|
* incorporate content rendered with Cogl.
|
|
*
|
|
* Applications can check for OpenGLES 2.0 api support by checking for
|
|
* %COGL_FEATURE_ID_GLES2_CONTEXT support with cogl_has_feature().
|
|
*
|
|
* Since: 1.12
|
|
* Stability: unstable
|
|
*/
|
|
|
|
/**
|
|
* CoglGLES2Context:
|
|
*
|
|
* Represents an OpenGLES 2.0 api context used as a sandbox for
|
|
* OpenGLES 2.0 state. This is comparable to an EGLContext for those
|
|
* who have used OpenGLES 2.0 with EGL before.
|
|
*
|
|
* Since: 1.12
|
|
* Stability: unstable
|
|
*/
|
|
typedef struct _CoglGLES2Context CoglGLES2Context;
|
|
|
|
/**
|
|
* CoglGLES2Vtable:
|
|
*
|
|
* Provides function pointers for the full OpenGLES 2.0 api. The
|
|
* api must be accessed this way and not by directly calling
|
|
* symbols of any system OpenGLES 2.0 api.
|
|
*
|
|
* Since: 1.12
|
|
* Stability: unstable
|
|
*/
|
|
typedef struct _CoglGLES2Vtable CoglGLES2Vtable;
|
|
|
|
struct _CoglGLES2Vtable
|
|
{
|
|
#define COGL_EXT_BEGIN(name, \
|
|
min_gl_major, min_gl_minor, \
|
|
gles_availability, \
|
|
extension_suffixes, extension_names)
|
|
|
|
#define COGL_EXT_FUNCTION(ret, name, args) \
|
|
ret (* name) args;
|
|
|
|
#define COGL_EXT_END()
|
|
|
|
#include <cogl/gl-prototypes/cogl-gles2-functions.h>
|
|
|
|
#undef COGL_EXT_BEGIN
|
|
#undef COGL_EXT_FUNCTION
|
|
#undef COGL_EXT_END
|
|
};
|
|
|
|
GQuark
|
|
_cogl_gles2_context_error_quark (void);
|
|
|
|
/**
|
|
* COGL_GLES2_CONTEXT_ERROR:
|
|
*
|
|
* An error domain for runtime exceptions relating to the
|
|
* cogl_gles2_context api.
|
|
*
|
|
* Since: 2.0
|
|
* Stability: unstable
|
|
*/
|
|
#define COGL_GLES2_CONTEXT_ERROR (_cogl_gles2_context_error_quark ())
|
|
|
|
/**
|
|
* CoglGLES2ContextError:
|
|
* @COGL_GLES2_CONTEXT_ERROR_UNSUPPORTED: Creating GLES2 contexts
|
|
* isn't supported. Applications should use cogl_has_feature() to
|
|
* check for the %COGL_FEATURE_ID_GLES2_CONTEXT.
|
|
* @COGL_GLES2_CONTEXT_ERROR_DRIVER: An underlying driver error
|
|
* occured.
|
|
*
|
|
* Error codes that relate to the cogl_gles2_context api.
|
|
*/
|
|
typedef enum { /*< prefix=COGL_GLES2_CONTEXT_ERROR >*/
|
|
COGL_GLES2_CONTEXT_ERROR_UNSUPPORTED,
|
|
COGL_GLES2_CONTEXT_ERROR_DRIVER
|
|
} CoglGLES2ContextError;
|
|
|
|
/**
|
|
* cogl_gles2_context_new:
|
|
* @ctx: A #CoglContext
|
|
* @error: A pointer to a #GError for returning exceptions
|
|
*
|
|
* Allocates a new OpenGLES 2.0 context that can be used to render to
|
|
* #CoglOffscreen framebuffers (Rendering to #CoglOnscreen
|
|
* framebuffers is not currently supported).
|
|
*
|
|
* To actually access the OpenGLES 2.0 api itself you need to use
|
|
* cogl_gles2_context_get_vtable(). You should not try to directly link
|
|
* to and use the symbols provided by the a system OpenGLES 2.0
|
|
* driver.
|
|
*
|
|
* Once you have allocated an OpenGLES 2.0 context you can make it
|
|
* current using cogl_push_gles2_context(). For those familiar with
|
|
* using the EGL api, this serves a similar purpose to eglMakeCurrent.
|
|
*
|
|
* <note>Before using this api applications can check for OpenGLES 2.0
|
|
* api support by checking for %COGL_FEATURE_ID_GLES2_CONTEXT support
|
|
* with cogl_has_feature(). This function will return %FALSE and
|
|
* return an %COGL_GLES2_CONTEXT_ERROR_UNSUPPORTED error if the
|
|
* feature isn't available.</note>
|
|
*
|
|
* Since: 2.0
|
|
* Return value: A newly allocated #CoglGLES2Context or %NULL if there
|
|
* was an error and @error will be updated in that case.
|
|
* Stability: unstable
|
|
*/
|
|
CoglGLES2Context *
|
|
cogl_gles2_context_new (CoglContext *ctx, GError **error);
|
|
|
|
/**
|
|
* cogl_gles2_context_get_vtable:
|
|
* @gles2_ctx: A #CoglGLES2Context allocated with
|
|
* cogl_gles2_context_new()
|
|
*
|
|
* Queries the OpenGLES 2.0 api function pointers that should be
|
|
* used for rendering with the given @gles2_ctx.
|
|
*
|
|
* <note>You should not try to directly link to and use the symbols
|
|
* provided by any system OpenGLES 2.0 driver.</note>
|
|
*
|
|
* Since: 2.0
|
|
* Return value: A pointer to a #CoglGLES2Vtable providing pointers
|
|
* to functions for the full OpenGLES 2.0 api.
|
|
* Stability: unstable
|
|
*/
|
|
const CoglGLES2Vtable *
|
|
cogl_gles2_context_get_vtable (CoglGLES2Context *gles2_ctx);
|
|
|
|
/**
|
|
* cogl_push_gles2_context:
|
|
* @ctx: A #CoglContext
|
|
* @gles2_ctx: A #CoglGLES2Context allocated with
|
|
* cogl_gles2_context_new()
|
|
* @read_buffer: A #CoglFramebuffer to access to read operations
|
|
* such as glReadPixels. (must be a #CoglOffscreen
|
|
* framebuffer currently)
|
|
* @write_buffer: A #CoglFramebuffer to access for drawing operations
|
|
* such as glDrawArrays. (must be a #CoglOffscreen
|
|
* framebuffer currently)
|
|
* @error: A pointer to a #GError for returning exceptions
|
|
*
|
|
* Pushes the given @gles2_ctx onto a stack associated with @ctx so
|
|
* that the OpenGLES 2.0 api can be used instead of the Cogl
|
|
* rendering apis to read and write to the specified framebuffers.
|
|
*
|
|
* Usage of the api available through a #CoglGLES2Vtable is only
|
|
* allowed between cogl_push_gles2_context() and
|
|
* cogl_pop_gles2_context() calls.
|
|
*
|
|
* If there is a runtime problem with switching over to the given
|
|
* @gles2_ctx then this function will return %FALSE and return
|
|
* an error through @error.
|
|
*
|
|
* Since: 2.0
|
|
* Return value: %TRUE if operation was successfull or %FALSE
|
|
* otherwise and @error will be updated.
|
|
* Stability: unstable
|
|
*/
|
|
CoglBool
|
|
cogl_push_gles2_context (CoglContext *ctx,
|
|
CoglGLES2Context *gles2_ctx,
|
|
CoglFramebuffer *read_buffer,
|
|
CoglFramebuffer *write_buffer,
|
|
GError **error);
|
|
|
|
/**
|
|
* cogl_pop_gles2_context:
|
|
* @ctx: A #CoglContext
|
|
*
|
|
* Restores the previously active #CoglGLES2Context if there
|
|
* were nested calls to cogl_push_gles2_context() or otherwise
|
|
* restores the ability to render with the Cogl api instead
|
|
* of OpenGLES 2.0.
|
|
*
|
|
* The behaviour is undefined if calls to cogl_pop_gles2_context()
|
|
* are not balenced with the number of corresponding calls to
|
|
* cogl_push_gles2_context().
|
|
*
|
|
* Since: 2.0
|
|
* Stability: unstable
|
|
*/
|
|
void
|
|
cogl_pop_gles2_context (CoglContext *ctx);
|
|
|
|
/**
|
|
* cogl_gles2_get_current_vtable:
|
|
*
|
|
* Returns the OpenGL ES 2.0 api vtable for the currently pushed
|
|
* #CoglGLES2Context (last pushed with cogl_push_gles2_context()) or
|
|
* %NULL if no #CoglGLES2Context has been pushed.
|
|
*
|
|
* Return value: The #CoglGLES2Vtable for the currently pushed
|
|
* #CoglGLES2Context or %NULL if none has been pushed.
|
|
* Since: 2.0
|
|
* Stability: unstable
|
|
*/
|
|
CoglGLES2Vtable *
|
|
cogl_gles2_get_current_vtable (void);
|
|
|
|
/**
|
|
* cogl_gles2_texture_2d_new_from_handle:
|
|
* @ctx: A #CoglContext
|
|
* @gles2_ctx: A #CoglGLES2Context allocated with
|
|
* cogl_gles2_context_new()
|
|
* @handle: An OpenGL ES 2.0 texture handle created with
|
|
* glGenTextures()
|
|
*
|
|
* Creates a #CoglTexture2D from an OpenGL ES 2.0 texture handle that
|
|
* was created within the given @gles2_ctx via glGenTextures(). The
|
|
* texture needs to have been associated with the GL_TEXTURE_2D target.
|
|
*
|
|
* <note>This interface is only intended for sharing textures to read
|
|
* from. The behaviour is undefined if the texture is modified using
|
|
* the Cogl api.</note>
|
|
*
|
|
* <note>Applications should only pass this function handles that were
|
|
* created via a #CoglGLES2Vtable or via libcogl-gles2 and not pass
|
|
* handles created directly using the system's native libGLESv2
|
|
* api.</note>
|
|
*
|
|
* Since: 2.0
|
|
* Stability: unstable
|
|
*/
|
|
CoglTexture2D *
|
|
cogl_gles2_texture_2d_new_from_handle (CoglContext *ctx,
|
|
CoglGLES2Context *gles2_ctx,
|
|
unsigned int handle,
|
|
int width,
|
|
int height,
|
|
CoglPixelFormat internal_format,
|
|
GError **error);
|
|
|
|
/**
|
|
* cogl_gles2_texture_get_handle:
|
|
* @handle: A return location for an OpenGL ES 2.0 texture handle
|
|
* @target: A return location for an OpenGL ES 2.0 texture target
|
|
*
|
|
* Gets an OpenGL ES 2.0 texture handle for a #CoglTexture that can
|
|
* then be referenced by a #CoglGLES2Context. As well as returning
|
|
* a texture handle the texture's target (such as GL_TEXTURE_2D) is
|
|
* also returned.
|
|
*
|
|
* If the #CoglTexture can not be shared with a #CoglGLES2Context then
|
|
* this function will return %FALSE.
|
|
*
|
|
* This api does not affect the lifetime of the CoglTexture and you
|
|
* must take care not to reference the returned handle after the
|
|
* original texture has been freed.
|
|
*
|
|
* <note>This interface is only intended for sharing textures to read
|
|
* from. The behaviour is undefined if the texture is modified by a
|
|
* GLES2 context.</note>
|
|
*
|
|
* <note>This function will only return %TRUE for low-level
|
|
* #CoglTexture<!-- -->s such as #CoglTexture2D or #CoglTexture3D but
|
|
* not for high level meta textures such as
|
|
* #CoglTexture2DSliced</note>
|
|
*
|
|
* <note>The handle returned should not be passed directly to a system
|
|
* OpenGL ES 2.0 library, the handle is only intended to be used via
|
|
* a #CoglGLES2Vtable or via libcogl-gles2.</note>
|
|
*
|
|
* Return value: %TRUE if a handle and target could be returned
|
|
* otherwise %FALSE is returned.
|
|
* Since: 2.0
|
|
* Stability: unstable
|
|
*/
|
|
CoglBool
|
|
cogl_gles2_texture_get_handle (CoglTexture *texture,
|
|
unsigned int *handle,
|
|
unsigned int *target);
|
|
|
|
/**
|
|
* cogl_is_gles2_context:
|
|
* @object: A #CoglObject pointer
|
|
*
|
|
* Gets whether the given object references a #CoglGLES2Context.
|
|
*
|
|
* Return value: %TRUE if the object references a #CoglGLES2Context
|
|
* and %FALSE otherwise.
|
|
* Since: 2.0
|
|
* Stability: unstable
|
|
*/
|
|
CoglBool
|
|
cogl_is_gles2_context (void *object);
|
|
|
|
G_END_DECLS
|
|
|
|
#endif /* __COGL_GLES2_H__ */
|
|
|