bb3a008318
Cogl's support for offscreen rendering was originally written just to support
the clutter_texture_new_from_actor API and due to lack of documentation and
several confusing - non orthogonal - side effects of using the API it wasn't
really possible to use directly.
This commit does a number of things:
- It removes {gl,gles}/cogl-fbo.{c,h} and adds shared cogl-draw-buffer.{c,h}
files instead which should be easier to maintain.
- internally CoglFbo objects are now called CoglDrawBuffers. A
CoglDrawBuffer is an abstract base class that is inherited from to
implement CoglOnscreen and CoglOffscreen draw buffers. CoglOffscreen draw
buffers will initially be used to support the
cogl_offscreen_new_to_texture API, and CoglOnscreen draw buffers will
start to be used internally to represent windows as we aim to migrate some
of Clutter's backend code to Cogl.
- It makes draw buffer objects the owners of the following state:
- viewport
- projection matrix stack
- modelview matrix stack
- clip state
(This means when you switch between draw buffers you will automatically be
switching to their associated viewport, matrix and clip state)
Aside from hopefully making cogl_offscreen_new_to_texture be more useful
short term by having simpler and well defined semantics for
cogl_set_draw_buffer, as mentioned above this is the first step for a couple
of other things:
- Its a step toward moving ownership for windows down from Clutter backends
into Cogl, by (internally at least) introducing the CoglOnscreen draw
buffer. Note: the plan is that cogl_set_draw_buffer will accept on or
offscreen draw buffer handles, and the "target" argument will become
redundant since we will instead query the type of the given draw buffer
handle.
- Because we have a common type for on and offscreen framebuffers we can
provide a unified API for framebuffer management. Things like:
- blitting between buffers
- managing ancillary buffers (e.g. attaching depth and stencil buffers)
- size requisition
- clearing
140 lines
3.9 KiB
C
140 lines
3.9 KiB
C
/*
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* Cogl
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*
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* An object oriented GL/GLES Abstraction/Utility Layer
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*
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* Copyright (C) 2007,2008,2009 Intel Corporation.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <string.h>
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#include "cogl.h"
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#include "cogl-internal.h"
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#include "cogl-context.h"
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typedef struct _CoglGLSymbolTableEntry
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{
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const char *name;
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void *ptr;
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} CoglGLSymbolTableEntry;
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gboolean
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cogl_check_extension (const gchar *name, const gchar *ext)
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{
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gchar *end;
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gint name_len, n;
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if (name == NULL || ext == NULL)
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return FALSE;
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end = (gchar*)(ext + strlen(ext));
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name_len = strlen(name);
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while (ext < end)
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{
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n = strcspn(ext, " ");
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if ((name_len == n) && (!strncmp(name, ext, n)))
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return TRUE;
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ext += (n + 1);
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}
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return FALSE;
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}
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gboolean
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_cogl_resolve_gl_symbols (CoglGLSymbolTableEntry *symbol_table,
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const char *suffix)
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{
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int i;
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gboolean status = TRUE;
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for (i = 0; symbol_table[i].name; i++)
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{
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char *full_name = g_strdup_printf ("%s%s", symbol_table[i].name, suffix);
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*((CoglFuncPtr *)symbol_table[i].ptr) = cogl_get_proc_address (full_name);
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g_free (full_name);
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if (!*((CoglFuncPtr *)symbol_table[i].ptr))
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{
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status = FALSE;
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break;
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}
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}
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return status;
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}
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void
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_cogl_features_init (void)
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{
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CoglFeatureFlags flags = 0;
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int max_clip_planes = 0;
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GLint num_stencil_bits = 0;
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const char *gl_extensions;
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_COGL_GET_CONTEXT (ctx, NO_RETVAL);
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gl_extensions = (const char*) glGetString (GL_EXTENSIONS);
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if (cogl_check_extension ("GL_OES_framebuffer_object", gl_extensions))
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{
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g_assert (0);
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CoglGLSymbolTableEntry symbol_table[] = {
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{"glGenRenderbuffers", &ctx->drv.pf_glGenRenderbuffers},
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{"glDeleteRenderbuffers", &ctx->drv.pf_glDeleteRenderbuffers},
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{"glBindRenderbuffer", &ctx->drv.pf_glBindRenderbuffer},
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{"glRenderbufferStorage", &ctx->drv.pf_glRenderbufferStorage},
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{"glGenFramebuffers", &ctx->drv.pf_glGenFramebuffers},
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{"glBindFramebuffer", &ctx->drv.pf_glBindFramebuffer},
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{"glFramebufferTexture2D", &ctx->drv.pf_glFramebufferTexture2D},
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{"glFramebufferRenderbuffer", &ctx->drv.pf_glFramebufferRenderbuffer},
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{"glCheckFramebufferStatus", &ctx->drv.pf_glCheckFramebufferStatus},
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{"glDeleteFramebuffers", &ctx->drv.pf_glDeleteFramebuffers},
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{"glGenerateMipmap", &ctx->drv.pf_glGenerateMipmap},
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{NULL, NULL}
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};
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if (_cogl_resolve_gl_symbols (symbol_table, "OES"))
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flags |= COGL_FEATURE_OFFSCREEN;
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}
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GE( glGetIntegerv (GL_STENCIL_BITS, &num_stencil_bits) );
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/* We need at least three stencil bits to combine clips */
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if (num_stencil_bits > 2)
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flags |= COGL_FEATURE_STENCIL_BUFFER;
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GE( glGetIntegerv (GL_MAX_CLIP_PLANES, &max_clip_planes) );
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if (max_clip_planes >= 4)
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flags |= COGL_FEATURE_FOUR_CLIP_PLANES;
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#ifdef HAVE_COGL_GLES2
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flags |= COGL_FEATURE_SHADERS_GLSL | COGL_FEATURE_OFFSCREEN;
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#endif
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flags |= COGL_FEATURE_VBOS;
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/* Cache features */
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ctx->feature_flags = flags;
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ctx->features_cached = TRUE;
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}
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