gtk2/gsk/ngl/gsknglcommandqueueprivate.h
Christian Hergert 2a38cecd33 gsk: add OpenGL based GskNglRenderer
The primary goal here was to cleanup the current GL renderer to make
maintenance easier going forward. Furthermore, it tracks state to allow
us to implement more advanced renderer features going forward.

Reordering

This renderer will reorder batches by render target to reduce the number
of times render targets are changed.

In the future, we could also reorder by program within the render target
if we can determine that vertices do not overlap.

Uniform Snapshots

To allow for reordering of batches all uniforms need to be tracked for
the programs. This allows us to create the full uniform state when the
batch has been moved into a new position.

Some care was taken as it can be performance sensitive.

Attachment Snapshots

Similar to uniform snapshots, we need to know all of the texture
attachments so that we can rebind them when necessary.

Render Jobs

To help isolate the process of creating GL commands from the renderer
abstraction a render job abstraction was added. This could be extended
in the future if we decided to do tiling.

Command Queue

Render jobs create batches using the command queue. The command queue
will snapshot uniform and attachment state so that it can reorder
batches right before executing them.

Currently, the only reordering done is to ensure that we only visit
each render target once. We could extend this by tracking vertices,
attachments, and others.

This code currently uses an inline array helper to reduce overhead
from GArray which was showing up on profiles. It could be changed to
use GdkArray without too much work, but had roughly double the
instructions. Cycle counts have not yet been determined.

GLSL Programs

This was simplified to use XMACROS so that we can just extend one file
(gskglprograms.defs) instead of multiple places. The programs are added
as fields in the driver for easy access.

Driver

The driver manages textures, render targets, access to atlases,
programs, and more. There is one driver per display, by using the
shared GL context.

Some work could be done here to batch uploads so that we make fewer
calls to upload when sending icon theme data to the GPU. We'd need
to keep a copy of the atlas data for such purposes.
2021-02-23 14:41:52 -08:00

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C

/* gsknglcommandqueueprivate.h
*
* Copyright 2020 Christian Hergert <chergert@redhat.com>
*
* 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 2.1 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 program. If not, see <http://www.gnu.org/licenses/>.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*/
#ifndef __GSK_NGL_COMMAND_QUEUE_PRIVATE_H__
#define __GSK_NGL_COMMAND_QUEUE_PRIVATE_H__
#include <gsk/gskprofilerprivate.h>
#include "gskngltypesprivate.h"
#include "gsknglbufferprivate.h"
#include "gsknglattachmentstateprivate.h"
#include "gskngluniformstateprivate.h"
#include "inlinearray.h"
#include "../gl/gskglprofilerprivate.h"
G_BEGIN_DECLS
#define GSK_TYPE_GL_COMMAND_QUEUE (gsk_ngl_command_queue_get_type())
G_DECLARE_FINAL_TYPE (GskNglCommandQueue, gsk_ngl_command_queue, GSK, NGL_COMMAND_QUEUE, GObject)
typedef enum _GskNglCommandKind
{
/* The batch will perform a glClear() */
GSK_NGL_COMMAND_KIND_CLEAR,
/* The batch will perform a glDrawArrays() */
GSK_NGL_COMMAND_KIND_DRAW,
} GskNglCommandKind;
typedef struct _GskNglCommandBind
{
/* @texture is the value passed to glActiveTexture(), the "slot" the
* texture will be placed into. We always use GL_TEXTURE_2D so we don't
* waste any bits here to indicate that.
*/
guint texture : 5;
/* The identifier for the texture created with glGenTextures(). */
guint id : 27;
} GskNglCommandBind;
G_STATIC_ASSERT (sizeof (GskNglCommandBind) == 4);
typedef struct _GskNglCommandBatchAny
{
/* A GskNglCommandKind indicating what the batch will do */
guint kind : 8;
/* The program's identifier to use for determining if we can merge two
* batches together into a single set of draw operations. We put this
* here instead of the GskNglCommandDraw so that we can use the extra
* bits here without making the structure larger.
*/
guint program : 24;
/* The index of the next batch following this one. This is used
* as a sort of integer-based linked list to simplify out-of-order
* batching without moving memory around. -1 indicates last batch.
*/
gint16 next_batch_index;
/* Same but for reverse direction as we sort in reverse to get the
* batches ordered by framebuffer.
*/
gint16 prev_batch_index;
/* The viewport size of the batch. We check this as we process
* batches to determine if we need to resize the viewport.
*/
struct {
guint16 width;
guint16 height;
} viewport;
} GskNglCommandBatchAny;
G_STATIC_ASSERT (sizeof (GskNglCommandBatchAny) == 12);
typedef struct _GskNglCommandDraw
{
GskNglCommandBatchAny head;
/* There doesn't seem to be a limit on the framebuffer identifier that
* can be returned, so we have to use a whole unsigned for the framebuffer
* we are drawing to. When processing batches, we check to see if this
* changes and adjust the render target accordingly. Some sorting is
* performed to reduce the amount we change framebuffers.
*/
guint framebuffer;
/* The number of uniforms to change. This must be less than or equal to
* GL_MAX_UNIFORM_LOCATIONS but only guaranteed up to 1024 by any OpenGL
* implementation to be conformant.
*/
guint uniform_count : 11;
/* The number of textures to bind, which is only guaranteed up to 16
* by the OpenGL specification to be conformant.
*/
guint bind_count : 5;
/* GL_MAX_ELEMENTS_VERTICES specifies 33000 for this which requires 16-bit
* to address all possible counts <= GL_MAX_ELEMENTS_VERTICES.
*/
guint vbo_count : 16;
/* The offset within the VBO containing @vbo_count vertices to send with
* glDrawArrays().
*/
guint vbo_offset;
/* The offset within the array of uniform changes to be made containing
* @uniform_count #GskNglCommandUniform elements to apply.
*/
guint uniform_offset;
/* The offset within the array of bind changes to be made containing
* @bind_count #GskNglCommandBind elements to apply.
*/
guint bind_offset;
} GskNglCommandDraw;
G_STATIC_ASSERT (sizeof (GskNglCommandDraw) == 32);
typedef struct _GskNglCommandClear
{
GskNglCommandBatchAny any;
guint bits;
guint framebuffer;
} GskNglCommandClear;
G_STATIC_ASSERT (sizeof (GskNglCommandClear) == 20);
typedef struct _GskNglCommandUniform
{
GskNglUniformInfo info;
guint location;
} GskNglCommandUniform;
G_STATIC_ASSERT (sizeof (GskNglCommandUniform) == 8);
typedef union _GskNglCommandBatch
{
GskNglCommandBatchAny any;
GskNglCommandDraw draw;
GskNglCommandClear clear;
} GskNglCommandBatch;
G_STATIC_ASSERT (sizeof (GskNglCommandBatch) == 32);
DEFINE_INLINE_ARRAY (GskNglCommandBatches, gsk_ngl_command_batches, GskNglCommandBatch)
DEFINE_INLINE_ARRAY (GskNglCommandBinds, gsk_ngl_command_binds, GskNglCommandBind)
DEFINE_INLINE_ARRAY (GskNglCommandUniforms, gsk_ngl_command_uniforms, GskNglCommandUniform)
struct _GskNglCommandQueue
{
GObject parent_instance;
/* The GdkGLContext we make current before executing GL commands. */
GdkGLContext *context;
/* Array of GskNglCommandBatch which is a fixed size structure that will
* point into offsets of other arrays so that all similar data is stored
* together. The idea here is that we reduce the need for pointers so that
* using g_realloc()'d arrays is fine.
*/
GskNglCommandBatches batches;
/* Contains array of vertices and some wrapper code to help upload them
* to the GL driver. We can also tweak this to use double buffered arrays
* if we find that to be faster on some hardware and/or drivers.
*/
GskNglBuffer vertices;
/* The GskNglAttachmentState contains information about our FBO and texture
* attachments as we process incoming operations. We snapshot them into
* various batches so that we can compare differences between merge
* candidates.
*/
GskNglAttachmentState *attachments;
/* The uniform state across all programs. We snapshot this into batches so
* that we can compare uniform state between batches to give us more
* chances at merging draw commands.
*/
GskNglUniformState *uniforms;
/* Current program if we are in a draw so that we can send commands
* to the uniform state as needed.
*/
GskNglUniformProgram *program_info;
/* The profiler instance to deliver timing/etc data */
GskProfiler *profiler;
GskGLProfiler *gl_profiler;
/* Array of GskNglCommandBind which denote what textures need to be attached
* to which slot. GskNglCommandDraw.bind_offset and bind_count reference this
* array to determine what to attach.
*/
GskNglCommandBinds batch_binds;
/* Array of GskNglCommandUniform denoting which uniforms must be updated
* before the glDrawArrays() may be called. These are referenced from the
* GskNglCommandDraw.uniform_offset and uniform_count fields.
*/
GskNglCommandUniforms batch_uniforms;
/* String storage for debug groups */
GStringChunk *debug_groups;
/* Discovered max texture size when loading the command queue so that we
* can either scale down or slice textures to fit within this size. Assumed
* to be both height and width.
*/
int max_texture_size;
/* The index of the last batch in @batches, which may not be the element
* at the end of the array, as batches can be reordered. This is used to
* update the "next" index when adding a new batch.
*/
gint16 tail_batch_index;
gint16 head_batch_index;
/* Max framebuffer we used, so we can sort items faster */
guint fbo_max;
/* Various GSK and GDK metric counter ids */
struct {
GQuark n_frames;
GQuark cpu_time;
GQuark gpu_time;
guint n_binds;
guint n_fbos;
guint n_uniforms;
guint n_uploads;
guint queue_depth;
} metrics;
/* Counter for uploads on the frame */
guint n_uploads;
/* If we're inside a begin/end_frame pair */
guint in_frame : 1;
/* If we're inside of a begin_draw()/end_draw() pair. */
guint in_draw : 1;
/* If we've warned about truncating batches */
guint have_truncated : 1;
};
GskNglCommandQueue *gsk_ngl_command_queue_new (GdkGLContext *context,
GskNglUniformState *uniforms);
void gsk_ngl_command_queue_set_profiler (GskNglCommandQueue *self,
GskProfiler *profiler);
GdkGLContext *gsk_ngl_command_queue_get_context (GskNglCommandQueue *self);
void gsk_ngl_command_queue_make_current (GskNglCommandQueue *self);
void gsk_ngl_command_queue_begin_frame (GskNglCommandQueue *self);
void gsk_ngl_command_queue_end_frame (GskNglCommandQueue *self);
void gsk_ngl_command_queue_execute (GskNglCommandQueue *self,
guint surface_height,
guint scale_factor,
const cairo_region_t *scissor);
int gsk_ngl_command_queue_upload_texture (GskNglCommandQueue *self,
GdkTexture *texture,
guint x_offset,
guint y_offset,
guint width,
guint height,
int min_filter,
int mag_filter);
int gsk_ngl_command_queue_create_texture (GskNglCommandQueue *self,
int width,
int height,
int min_filter,
int mag_filter);
guint gsk_ngl_command_queue_create_framebuffer (GskNglCommandQueue *self);
gboolean gsk_ngl_command_queue_create_render_target (GskNglCommandQueue *self,
int width,
int height,
int min_filter,
int mag_filter,
guint *out_fbo_id,
guint *out_texture_id);
void gsk_ngl_command_queue_delete_program (GskNglCommandQueue *self,
guint program_id);
void gsk_ngl_command_queue_clear (GskNglCommandQueue *self,
guint clear_bits,
const graphene_rect_t *viewport);
void gsk_ngl_command_queue_begin_draw (GskNglCommandQueue *self,
GskNglUniformProgram *program_info,
guint width,
guint height);
void gsk_ngl_command_queue_end_draw (GskNglCommandQueue *self);
void gsk_ngl_command_queue_split_draw (GskNglCommandQueue *self);
static inline GskNglCommandBatch *
gsk_ngl_command_queue_get_batch (GskNglCommandQueue *self)
{
return gsk_ngl_command_batches_tail (&self->batches);
}
static inline GskNglDrawVertex *
gsk_ngl_command_queue_add_vertices (GskNglCommandQueue *self)
{
gsk_ngl_command_queue_get_batch (self)->draw.vbo_count += GSK_NGL_N_VERTICES;
return gsk_ngl_buffer_advance (&self->vertices, GSK_NGL_N_VERTICES);
}
static inline GskNglDrawVertex *
gsk_ngl_command_queue_add_n_vertices (GskNglCommandQueue *self,
guint count)
{
/* This is a batch form of gsk_ngl_command_queue_add_vertices(). Note that
* it does *not* add the count to .draw.vbo_count as the caller is responsible
* for that.
*/
return gsk_ngl_buffer_advance (&self->vertices, GSK_NGL_N_VERTICES * count);
}
static inline void
gsk_ngl_command_queue_retract_n_vertices (GskNglCommandQueue *self,
guint count)
{
/* Like gsk_ngl_command_queue_add_n_vertices(), this does not tweak
* the draw vbo_count.
*/
gsk_ngl_buffer_retract (&self->vertices, GSK_NGL_N_VERTICES * count);
}
static inline guint
gsk_ngl_command_queue_bind_framebuffer (GskNglCommandQueue *self,
guint framebuffer)
{
guint ret = self->attachments->fbo.id;
gsk_ngl_attachment_state_bind_framebuffer (self->attachments, framebuffer);
return ret;
}
G_END_DECLS
#endif /* __GSK_NGL_COMMAND_QUEUE_PRIVATE_H__ */