mutter/cogl/driver/gl/gles/cogl-driver-gles.c
Neil Roberts ff11a2b207 Use GL_ARB_texture_swizzle to emulate GL_ALPHA textures
The core profile of GL3 has removed support for component-alpha
textures. Previously the GL3 driver would just ignore this and try to
create them anyway. This would generate a GL error on Mesa.

To fix this the GL texture driver will now create a GL_RED texture
when GL_ALPHA textures are not supported natively. It will then set a
texture swizzle using the GL_ARB_texture_swizzle extension so that the
alpha component will be taken from the red component of the texture.
The swizzle is part of the texture object state so it only needs to be
set once when the texture is created.

The ‘gen’ virtual function of the texture driver has been changed to
also take the internal format as a parameter. The GL driver will now
set the swizzle as appropriate here.

The GL3 driver now reports an error if the texture swizzle extension
is not available because Cogl can't really work properly without out
it. The extension is part of GL 3.3 so it is quite likely that it has
wide support from drivers. Eventually we could get rid of this
requirement if we have our own GLSL front-end and we could generate
the swizzle ourselves.

When uploading or downloading texture data to or from a
component-alpha texture, we can no longer rely on GL to do the
conversion. The swizzle doesn't have any effect on the texture data
functions. In these cases Cogl will now force an intermediate buffer
to be used and it will manually do the conversion as it does for the
GLES drivers.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

(cherry picked from commit 32bacf81ebaa3be21a8f26af07d8f6eed6607652)
2013-01-22 17:48:04 +00:00

400 lines
13 KiB
C

/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2007,2008,2009 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/>.
*
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "cogl-internal.h"
#include "cogl-context-private.h"
#include "cogl-feature-private.h"
#include "cogl-renderer-private.h"
#include "cogl-private.h"
#include "cogl-framebuffer-gl-private.h"
#include "cogl-texture-2d-gl-private.h"
#include "cogl-attribute-gl-private.h"
#include "cogl-clip-stack-gl-private.h"
#include "cogl-buffer-gl-private.h"
#ifndef GL_UNSIGNED_INT_24_8
#define GL_UNSIGNED_INT_24_8 0x84FA
#endif
#ifndef GL_DEPTH_STENCIL
#define GL_DEPTH_STENCIL 0x84F9
#endif
static CoglBool
_cogl_driver_pixel_format_from_gl_internal (CoglContext *context,
GLenum gl_int_format,
CoglPixelFormat *out_format)
{
return TRUE;
}
static CoglPixelFormat
_cogl_driver_pixel_format_to_gl (CoglContext *context,
CoglPixelFormat format,
GLenum *out_glintformat,
GLenum *out_glformat,
GLenum *out_gltype)
{
CoglPixelFormat required_format;
GLenum glintformat;
GLenum glformat = 0;
GLenum gltype;
required_format = format;
/* Find GL equivalents */
switch (format)
{
case COGL_PIXEL_FORMAT_A_8:
glintformat = GL_ALPHA;
glformat = GL_ALPHA;
gltype = GL_UNSIGNED_BYTE;
break;
case COGL_PIXEL_FORMAT_G_8:
glintformat = GL_LUMINANCE;
glformat = GL_LUMINANCE;
gltype = GL_UNSIGNED_BYTE;
break;
case COGL_PIXEL_FORMAT_BGRA_8888:
case COGL_PIXEL_FORMAT_BGRA_8888_PRE:
/* There is an extension to support this format */
if ((context->private_feature_flags &
COGL_PRIVATE_FEATURE_TEXTURE_FORMAT_BGRA8888))
{
/* For some reason the extension says you have to specify
BGRA for the internal format too */
glintformat = GL_BGRA_EXT;
glformat = GL_BGRA_EXT;
gltype = GL_UNSIGNED_BYTE;
required_format = format;
break;
}
/* flow through */
/* Just one 24-bit ordering supported */
case COGL_PIXEL_FORMAT_RGB_888:
case COGL_PIXEL_FORMAT_BGR_888:
glintformat = GL_RGB;
glformat = GL_RGB;
gltype = GL_UNSIGNED_BYTE;
required_format = COGL_PIXEL_FORMAT_RGB_888;
break;
/* Just one 32-bit ordering supported */
case COGL_PIXEL_FORMAT_RGBA_8888:
case COGL_PIXEL_FORMAT_RGBA_8888_PRE:
case COGL_PIXEL_FORMAT_ARGB_8888:
case COGL_PIXEL_FORMAT_ARGB_8888_PRE:
case COGL_PIXEL_FORMAT_ABGR_8888:
case COGL_PIXEL_FORMAT_ABGR_8888_PRE:
case COGL_PIXEL_FORMAT_RGBA_1010102:
case COGL_PIXEL_FORMAT_RGBA_1010102_PRE:
case COGL_PIXEL_FORMAT_BGRA_1010102:
case COGL_PIXEL_FORMAT_BGRA_1010102_PRE:
case COGL_PIXEL_FORMAT_ABGR_2101010:
case COGL_PIXEL_FORMAT_ABGR_2101010_PRE:
case COGL_PIXEL_FORMAT_ARGB_2101010:
case COGL_PIXEL_FORMAT_ARGB_2101010_PRE:
glintformat = GL_RGBA;
glformat = GL_RGBA;
gltype = GL_UNSIGNED_BYTE;
required_format = COGL_PIXEL_FORMAT_RGBA_8888;
required_format |= (format & COGL_PREMULT_BIT);
break;
/* The following three types of channel ordering
* are always defined using system word byte
* ordering (even according to GLES spec) */
case COGL_PIXEL_FORMAT_RGB_565:
glintformat = GL_RGB;
glformat = GL_RGB;
gltype = GL_UNSIGNED_SHORT_5_6_5;
break;
case COGL_PIXEL_FORMAT_RGBA_4444:
case COGL_PIXEL_FORMAT_RGBA_4444_PRE:
glintformat = GL_RGBA;
glformat = GL_RGBA;
gltype = GL_UNSIGNED_SHORT_4_4_4_4;
break;
case COGL_PIXEL_FORMAT_RGBA_5551:
case COGL_PIXEL_FORMAT_RGBA_5551_PRE:
glintformat = GL_RGBA;
glformat = GL_RGBA;
gltype = GL_UNSIGNED_SHORT_5_5_5_1;
break;
case COGL_PIXEL_FORMAT_DEPTH_16:
glintformat = GL_DEPTH_COMPONENT;
glformat = GL_DEPTH_COMPONENT;
gltype = GL_UNSIGNED_SHORT;
break;
case COGL_PIXEL_FORMAT_DEPTH_32:
glintformat = GL_DEPTH_COMPONENT;
glformat = GL_DEPTH_COMPONENT;
gltype = GL_UNSIGNED_INT;
break;
case COGL_PIXEL_FORMAT_DEPTH_24_STENCIL_8:
glintformat = GL_DEPTH_STENCIL;
glformat = GL_DEPTH_STENCIL;
gltype = GL_UNSIGNED_INT_24_8;
break;
case COGL_PIXEL_FORMAT_ANY:
case COGL_PIXEL_FORMAT_YUV:
g_assert_not_reached ();
break;
}
/* All of the pixel formats are handled above so if this hits then
we've been given an invalid pixel format */
g_assert (glformat != 0);
if (out_glintformat != NULL)
*out_glintformat = glintformat;
if (out_glformat != NULL)
*out_glformat = glformat;
if (out_gltype != NULL)
*out_gltype = gltype;
return required_format;
}
static CoglBool
_cogl_driver_update_features (CoglContext *context,
CoglError **error)
{
CoglPrivateFeatureFlags private_flags = 0;
CoglFeatureFlags flags = 0;
char **gl_extensions;
int num_stencil_bits = 0;
/* We have to special case getting the pointer to the glGetString
function because we need to use it to determine what functions we
can expect */
context->glGetString =
(void *) _cogl_renderer_get_proc_address (context->display->renderer,
"glGetString",
TRUE);
gl_extensions = _cogl_context_get_gl_extensions (context);
if (G_UNLIKELY (COGL_DEBUG_ENABLED (COGL_DEBUG_WINSYS)))
{
char *all_extensions = g_strjoinv (" ", gl_extensions);
COGL_NOTE (WINSYS,
"Checking features\n"
" GL_VENDOR: %s\n"
" GL_RENDERER: %s\n"
" GL_VERSION: %s\n"
" GL_EXTENSIONS: %s",
context->glGetString (GL_VENDOR),
context->glGetString (GL_RENDERER),
_cogl_context_get_gl_version (context),
all_extensions);
g_free (all_extensions);
}
context->glsl_major = 1;
context->glsl_minor = 0;
_cogl_gpu_info_init (context, &context->gpu);
_cogl_feature_check_ext_functions (context,
-1 /* GL major version */,
-1 /* GL minor version */,
gl_extensions);
GE( context, glGetIntegerv (GL_STENCIL_BITS, &num_stencil_bits) );
/* We need at least three stencil bits to combine clips */
if (num_stencil_bits > 2)
private_flags |= COGL_PRIVATE_FEATURE_STENCIL_BUFFER;
#ifdef HAVE_COGL_GLES
if (context->driver == COGL_DRIVER_GLES1)
{
int max_clip_planes;
GE( context, glGetIntegerv (GL_MAX_CLIP_PLANES, &max_clip_planes) );
if (max_clip_planes >= 4)
private_flags |= COGL_PRIVATE_FEATURE_FOUR_CLIP_PLANES;
}
#endif
if (context->driver == COGL_DRIVER_GLES2)
{
flags |= COGL_FEATURE_SHADERS_GLSL | COGL_FEATURE_OFFSCREEN;
/* Note GLES 2 core doesn't support mipmaps for npot textures or
* repeat modes other than CLAMP_TO_EDGE. */
flags |= COGL_FEATURE_TEXTURE_NPOT_BASIC;
flags |= COGL_FEATURE_DEPTH_RANGE;
COGL_FLAGS_SET (context->features, COGL_FEATURE_ID_GLSL, TRUE);
COGL_FLAGS_SET (context->features, COGL_FEATURE_ID_OFFSCREEN, TRUE);
COGL_FLAGS_SET (context->features,
COGL_FEATURE_ID_TEXTURE_NPOT_BASIC, TRUE);
COGL_FLAGS_SET (context->features, COGL_FEATURE_ID_DEPTH_RANGE, TRUE);
COGL_FLAGS_SET (context->features,
COGL_FEATURE_ID_MIRRORED_REPEAT, TRUE);
private_flags |= COGL_PRIVATE_FEATURE_BLEND_CONSTANT;
}
else if (context->driver == COGL_DRIVER_GLES1)
private_flags |= (COGL_PRIVATE_FEATURE_FIXED_FUNCTION |
COGL_PRIVATE_FEATURE_ALPHA_TEST |
COGL_PRIVATE_FEATURE_BUILTIN_POINT_SIZE_UNIFORM);
private_flags |= (COGL_PRIVATE_FEATURE_VBOS |
COGL_PRIVATE_FEATURE_ANY_GL |
COGL_PRIVATE_FEATURE_ALPHA_TEXTURES);
/* Both GLES 1.1 and GLES 2.0 support point sprites in core */
flags |= COGL_FEATURE_POINT_SPRITE;
COGL_FLAGS_SET (context->features, COGL_FEATURE_ID_POINT_SPRITE, TRUE);
if (context->glGenRenderbuffers)
{
flags |= COGL_FEATURE_OFFSCREEN;
COGL_FLAGS_SET (context->features, COGL_FEATURE_ID_OFFSCREEN, TRUE);
}
if (context->glBlitFramebuffer)
private_flags |= COGL_PRIVATE_FEATURE_OFFSCREEN_BLIT;
if (_cogl_check_extension ("GL_OES_element_index_uint", gl_extensions))
{
flags |= COGL_FEATURE_UNSIGNED_INT_INDICES;
COGL_FLAGS_SET (context->features,
COGL_FEATURE_ID_UNSIGNED_INT_INDICES, TRUE);
}
if (_cogl_check_extension ("GL_OES_depth_texture", gl_extensions))
{
flags |= COGL_FEATURE_DEPTH_TEXTURE;
COGL_FLAGS_SET (context->features, COGL_FEATURE_ID_DEPTH_TEXTURE, TRUE);
}
if (_cogl_check_extension ("GL_OES_texture_npot", gl_extensions))
{
flags |= (COGL_FEATURE_TEXTURE_NPOT |
COGL_FEATURE_TEXTURE_NPOT_BASIC |
COGL_FEATURE_TEXTURE_NPOT_MIPMAP |
COGL_FEATURE_TEXTURE_NPOT_REPEAT);
COGL_FLAGS_SET (context->features,
COGL_FEATURE_ID_TEXTURE_NPOT, TRUE);
COGL_FLAGS_SET (context->features,
COGL_FEATURE_ID_TEXTURE_NPOT_BASIC, TRUE);
COGL_FLAGS_SET (context->features,
COGL_FEATURE_ID_TEXTURE_NPOT_MIPMAP, TRUE);
COGL_FLAGS_SET (context->features,
COGL_FEATURE_ID_TEXTURE_NPOT_REPEAT, TRUE);
}
else if (_cogl_check_extension ("GL_IMG_texture_npot", gl_extensions))
{
flags |= (COGL_FEATURE_TEXTURE_NPOT_BASIC |
COGL_FEATURE_TEXTURE_NPOT_MIPMAP);
COGL_FLAGS_SET (context->features,
COGL_FEATURE_ID_TEXTURE_NPOT_BASIC, TRUE);
COGL_FLAGS_SET (context->features,
COGL_FEATURE_ID_TEXTURE_NPOT_MIPMAP, TRUE);
}
if (context->glTexImage3D)
{
flags |= COGL_FEATURE_TEXTURE_3D;
COGL_FLAGS_SET (context->features, COGL_FEATURE_ID_TEXTURE_3D, TRUE);
}
if (context->glMapBuffer)
{
/* The GL_OES_mapbuffer extension doesn't support mapping for
read */
flags |= COGL_FEATURE_MAP_BUFFER_FOR_WRITE;
COGL_FLAGS_SET (context->features,
COGL_FEATURE_ID_MAP_BUFFER_FOR_WRITE, TRUE);
}
if (context->glEGLImageTargetTexture2D)
private_flags |= COGL_PRIVATE_FEATURE_TEXTURE_2D_FROM_EGL_IMAGE;
if (_cogl_check_extension ("GL_OES_packed_depth_stencil", gl_extensions))
private_flags |= COGL_PRIVATE_FEATURE_OES_PACKED_DEPTH_STENCIL;
if (_cogl_check_extension ("GL_EXT_texture_format_BGRA8888", gl_extensions))
private_flags |= COGL_PRIVATE_FEATURE_TEXTURE_FORMAT_BGRA8888;
if (_cogl_check_extension ("GL_EXT_unpack_subimage", gl_extensions))
private_flags |= COGL_PRIVATE_FEATURE_UNPACK_SUBIMAGE;
/* Cache features */
context->private_feature_flags |= private_flags;
context->feature_flags |= flags;
g_strfreev (gl_extensions);
return TRUE;
}
const CoglDriverVtable
_cogl_driver_gles =
{
_cogl_driver_pixel_format_from_gl_internal,
_cogl_driver_pixel_format_to_gl,
_cogl_driver_update_features,
_cogl_offscreen_gl_allocate,
_cogl_offscreen_gl_free,
_cogl_framebuffer_gl_flush_state,
_cogl_framebuffer_gl_clear,
_cogl_framebuffer_gl_query_bits,
_cogl_framebuffer_gl_finish,
_cogl_framebuffer_gl_discard_buffers,
_cogl_framebuffer_gl_draw_attributes,
_cogl_framebuffer_gl_draw_indexed_attributes,
_cogl_texture_2d_gl_free,
_cogl_texture_2d_gl_can_create,
_cogl_texture_2d_gl_init,
_cogl_texture_2d_gl_new_with_size,
_cogl_texture_2d_gl_new_from_bitmap,
#if defined (COGL_HAS_EGL_SUPPORT) && defined (EGL_KHR_image_base)
_cogl_egl_texture_2d_gl_new_from_image,
#endif
_cogl_texture_2d_gl_copy_from_framebuffer,
_cogl_texture_2d_gl_get_gl_handle,
_cogl_texture_2d_gl_generate_mipmap,
_cogl_texture_2d_gl_copy_from_bitmap,
NULL, /* texture_2d_get_data */
_cogl_gl_flush_attributes_state,
_cogl_clip_stack_gl_flush,
_cogl_buffer_gl_create,
_cogl_buffer_gl_destroy,
_cogl_buffer_gl_map_range,
_cogl_buffer_gl_unmap,
_cogl_buffer_gl_set_data,
};