gtk/gdk/gdkgltexture.c
Benjamin Otte c9f54ca371 texture: Export gdk_texture_get_format()
The API docs outline why quite well.

This should make it possible to do saving of textures to image files
without any private API with the same featureset that GTK uses.

Also remove the gsktextureprivate.h include where
gdk_texture_get_format() was the only reason for it.
2023-02-15 00:39:18 +01:00

465 lines
13 KiB
C

/* gdkgltexture.c
*
* Copyright 2016 Benjamin Otte
*
* 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/>.
*/
#include "config.h"
#include "gdkgltextureprivate.h"
#include "gdkdisplayprivate.h"
#include "gdkglcontextprivate.h"
#include "gdkmemoryformatprivate.h"
#include "gdkmemorytextureprivate.h"
#include <epoxy/gl.h>
/**
* GdkGLTexture:
*
* A GdkTexture representing a GL texture object.
*/
struct _GdkGLTexture {
GdkTexture parent_instance;
GdkGLContext *context;
guint id;
GdkTexture *saved;
GDestroyNotify destroy;
gpointer data;
};
struct _GdkGLTextureClass {
GdkTextureClass parent_class;
};
G_DEFINE_TYPE (GdkGLTexture, gdk_gl_texture, GDK_TYPE_TEXTURE)
static void
drop_gl_resources (GdkGLTexture *self)
{
if (self->destroy)
{
self->destroy (self->data);
self->destroy = NULL;
self->data = NULL;
}
g_clear_object (&self->context);
self->id = 0;
}
static void
gdk_gl_texture_dispose (GObject *object)
{
GdkGLTexture *self = GDK_GL_TEXTURE (object);
drop_gl_resources (self);
g_clear_object (&self->saved);
G_OBJECT_CLASS (gdk_gl_texture_parent_class)->dispose (object);
}
typedef void (* GLFunc) (GdkGLTexture *self,
GdkGLContext *context,
gpointer data);
typedef struct _InvokeData
{
GdkGLTexture *self;
volatile int spinlock;
GLFunc func;
gpointer data;
} InvokeData;
static gboolean
gdk_gl_texture_invoke_callback (gpointer data)
{
InvokeData *invoke = data;
GdkGLContext *context;
context = gdk_display_get_gl_context (gdk_gl_context_get_display (invoke->self->context));
gdk_gl_context_make_current (context);
glBindTexture (GL_TEXTURE_2D, invoke->self->id);
invoke->func (invoke->self, context, invoke->data);
g_atomic_int_set (&invoke->spinlock, 1);
return FALSE;
}
static void
gdk_gl_texture_run (GdkGLTexture *self,
GLFunc func,
gpointer data)
{
InvokeData invoke = { self, 0, func, data };
g_main_context_invoke (NULL, gdk_gl_texture_invoke_callback, &invoke);
while (g_atomic_int_get (&invoke.spinlock) == 0);
}
typedef struct _Download Download;
struct _Download
{
GdkMemoryFormat format;
guchar *data;
gsize stride;
};
static gboolean
gdk_gl_texture_find_format (gboolean use_es,
GLint gl_format,
GLint gl_type,
GdkMemoryFormat *out_format)
{
GdkMemoryFormat format;
for (format = 0; format < GDK_MEMORY_N_FORMATS; format++)
{
GLenum q_internal_format, q_format, q_type;
if (!gdk_memory_format_gl_format (format, use_es, &q_internal_format, &q_format, &q_type))
continue;
if (q_format != gl_format || q_type != gl_type)
continue;
*out_format = format;
return TRUE;
}
return FALSE;
}
static inline void
gdk_gl_texture_do_download (GdkGLTexture *self,
GdkGLContext *context,
gpointer download_)
{
GdkTexture *texture = GDK_TEXTURE (self);
gsize expected_stride;
Download *download = download_;
GLenum gl_internal_format, gl_format, gl_type;
expected_stride = texture->width * gdk_memory_format_bytes_per_pixel (download->format);
if (download->stride == expected_stride &&
!gdk_gl_context_get_use_es (context) &&
gdk_memory_format_gl_format (download->format, TRUE, &gl_internal_format, &gl_format, &gl_type))
{
glGetTexImage (GL_TEXTURE_2D,
0,
gl_format,
gl_type,
download->data);
}
else
{
GdkMemoryFormat actual_format;
GLint gl_read_format, gl_read_type;
GLuint fbo;
glGenFramebuffers (1, &fbo);
glBindFramebuffer (GL_FRAMEBUFFER, fbo);
glFramebufferTexture2D (GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, self->id, 0);
if (gdk_gl_context_check_version (context, 4, 3, 3, 1))
{
glGetFramebufferParameteriv (GL_FRAMEBUFFER, GL_IMPLEMENTATION_COLOR_READ_FORMAT, &gl_read_format);
glGetFramebufferParameteriv (GL_FRAMEBUFFER, GL_IMPLEMENTATION_COLOR_READ_TYPE, &gl_read_type);
if (!gdk_gl_texture_find_format (gdk_gl_context_get_use_es (context), gl_read_format, gl_read_type, &actual_format))
actual_format = GDK_MEMORY_R8G8B8A8_PREMULTIPLIED; /* pray */
}
else
{
gl_read_format = GL_RGBA;
gl_read_type = GL_UNSIGNED_BYTE;
actual_format = GDK_MEMORY_R8G8B8A8_PREMULTIPLIED;
}
if (download->format == actual_format &&
(download->stride == expected_stride))
{
glReadPixels (0, 0,
texture->width, texture->height,
gl_read_format,
gl_read_type,
download->data);
}
else
{
gsize actual_bpp = gdk_memory_format_bytes_per_pixel (actual_format);
guchar *pixels = g_malloc_n (texture->width * actual_bpp, texture->height);
glReadPixels (0, 0,
texture->width, texture->height,
gl_read_format,
gl_read_type,
pixels);
gdk_memory_convert (download->data,
download->stride,
download->format,
pixels,
texture->width * actual_bpp,
actual_format,
texture->width,
texture->height);
g_free (pixels);
}
glBindFramebuffer (GL_FRAMEBUFFER, 0);
glDeleteFramebuffers (1, &fbo);
}
}
static void
gdk_gl_texture_download (GdkTexture *texture,
GdkMemoryFormat format,
guchar *data,
gsize stride)
{
GdkGLTexture *self = GDK_GL_TEXTURE (texture);
Download download;
if (self->saved)
{
gdk_texture_do_download (self->saved, format, data, stride);
return;
}
download.format = format;
download.data = data;
download.stride = stride;
gdk_gl_texture_run (self, gdk_gl_texture_do_download, &download);
}
static void
gdk_gl_texture_class_init (GdkGLTextureClass *klass)
{
GdkTextureClass *texture_class = GDK_TEXTURE_CLASS (klass);
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
texture_class->download = gdk_gl_texture_download;
gobject_class->dispose = gdk_gl_texture_dispose;
}
static void
gdk_gl_texture_init (GdkGLTexture *self)
{
}
GdkGLContext *
gdk_gl_texture_get_context (GdkGLTexture *self)
{
return self->context;
}
guint
gdk_gl_texture_get_id (GdkGLTexture *self)
{
return self->id;
}
/**
* gdk_gl_texture_release:
* @self: a `GdkTexture` wrapping a GL texture
*
* Releases the GL resources held by a `GdkGLTexture`.
*
* The texture contents are still available via the
* [method@Gdk.Texture.download] function, after this
* function has been called.
*/
void
gdk_gl_texture_release (GdkGLTexture *self)
{
GdkTexture *texture;
g_return_if_fail (GDK_IS_GL_TEXTURE (self));
g_return_if_fail (self->saved == NULL);
texture = GDK_TEXTURE (self);
self->saved = GDK_TEXTURE (gdk_memory_texture_from_texture (texture,
gdk_texture_get_format (texture)));
drop_gl_resources (self);
}
static void
gdk_gl_texture_determine_format (GdkGLTexture *self)
{
GdkTexture *texture = GDK_TEXTURE (self);
GLint active_texture;
GLint internal_format;
/* Abort if somebody else is GL-ing here... */
if (self->context != gdk_gl_context_get_current () ||
/* ... or glGetTexLevelParameter() isn't supported */
!gdk_gl_context_check_version (self->context, 0, 0, 3, 1))
{
texture->format = GDK_MEMORY_DEFAULT;
return;
}
/* We need to be careful about modifying the GL context, as this is not
* expected during construction */
glGetIntegerv (GL_TEXTURE_BINDING_2D, &active_texture);
glBindTexture (GL_TEXTURE_2D, self->id);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_INTERNAL_FORMAT, &internal_format);
switch (internal_format)
{
case GL_RGB8:
texture->format = GDK_MEMORY_R8G8B8;
break;
case GL_RGBA8:
texture->format = GDK_MEMORY_R8G8B8A8_PREMULTIPLIED;
break;
case GL_RGB16:
texture->format = GDK_MEMORY_R16G16B16;
break;
case GL_RGBA16:
texture->format = GDK_MEMORY_R16G16B16A16_PREMULTIPLIED;
break;
case GL_RGB16F:
texture->format = GDK_MEMORY_R16G16B16_FLOAT;
break;
case GL_RGBA16F:
texture->format = GDK_MEMORY_R16G16B16A16_FLOAT_PREMULTIPLIED;
break;
case GL_RGB32F:
texture->format = GDK_MEMORY_R32G32B32_FLOAT;
break;
case GL_RGBA32F:
texture->format = GDK_MEMORY_R32G32B32A32_FLOAT_PREMULTIPLIED;
break;
case GL_RGBA:
{
GLint red_size = 0;
GLint green_size = 0;
GLint blue_size = 0;
GLint alpha_size = 0;
GLint red_type = 0;
GLint green_type = 0;
GLint blue_type = 0;
GLint alpha_type = 0;
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_RED_TYPE, &red_type);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_GREEN_TYPE, &green_type);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_BLUE_TYPE, &blue_type);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_ALPHA_TYPE, &alpha_type);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_RED_SIZE, &red_size);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_GREEN_SIZE, &green_size);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_BLUE_SIZE, &blue_size);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_ALPHA_SIZE, &alpha_size);
#define CHECK_RGBA(rt,gt,bt,at,rs,gs,bs,as) \
(red_type == rt && green_type == gt && blue_type == bt && alpha_type == at && \
red_size == rs && green_size == gs && blue_size == bs && alpha_size == as)
if (CHECK_RGBA (GL_UNSIGNED_NORMALIZED, GL_UNSIGNED_NORMALIZED, GL_UNSIGNED_NORMALIZED, GL_UNSIGNED_NORMALIZED, 8, 8, 8, 8))
{
texture->format = GDK_MEMORY_R8G8B8A8_PREMULTIPLIED;
break;
}
#undef CHECK_RGBA
}
G_GNUC_FALLTHROUGH;
default:
g_warning ("Texture in unexpected format 0x%X (%d). File a bug about adding it to GTK", internal_format, internal_format);
/* fallback to the dumbest possible format
* so that even age old GLES can do it */
texture->format = GDK_MEMORY_R8G8B8A8_PREMULTIPLIED;
break;
}
glBindTexture (GL_TEXTURE_2D, active_texture);
}
/**
* gdk_gl_texture_new:
* @context: a `GdkGLContext`
* @id: the ID of a texture that was created with @context
* @width: the nominal width of the texture
* @height: the nominal height of the texture
* @destroy: a destroy notify that will be called when the GL resources
* are released
* @data: data that gets passed to @destroy
*
* Creates a new texture for an existing GL texture.
*
* Note that the GL texture must not be modified until @destroy is called,
* which will happen when the GdkTexture object is finalized, or due to
* an explicit call of [method@Gdk.GLTexture.release].
*
* Return value: (transfer full) (type GdkGLTexture): A newly-created
* `GdkTexture`
*/
GdkTexture *
gdk_gl_texture_new (GdkGLContext *context,
guint id,
int width,
int height,
GDestroyNotify destroy,
gpointer data)
{
GdkGLTexture *self;
g_return_val_if_fail (GDK_IS_GL_CONTEXT (context), NULL);
g_return_val_if_fail (id != 0, NULL);
g_return_val_if_fail (width > 0, NULL);
g_return_val_if_fail (height > 0, NULL);
self = g_object_new (GDK_TYPE_GL_TEXTURE,
"width", width,
"height", height,
NULL);
self->context = g_object_ref (context);
self->id = id;
self->destroy = destroy;
self->data = data;
gdk_gl_texture_determine_format (self);
return GDK_TEXTURE (self);
}