mutter/cogl/cogl-context.h
Neil Roberts 1d88e6c8ac cogl-journal: Attempt to clip manually to avoid breaking up batches
Before flushing the journal there is now a separate iteration that
will try to determine if the matrix of the clip stack and the matrix
of the rectangle in each entry are on the same plane. If they are it
can completely avoid the clip stack and instead manually modify the
vertex and texture coordinates to implement the clip. The has the
advantage that it won't break up batching if a single clipped
rectangle is used in a scene.

The software clip is only used if there is no user program and no
texture matrices. There is a threshold to the size of the batch where
it is assumed that it is worth the cost to break up a batch and
program the GPU to do the clipping. Currently this is set to 8
although this figure is plucked out of thin air.

To check whether the two matrices are on the same plane it tries to
determine if one of the matrices is just a simple translation of the
other. In the process of this it also works out what the translation
would be. These values can be used to translate the clip rectangle
into the coordinate space of the rectangle to be logged. Then we can
do the clip directly in the rectangle's coordinate space.
2010-12-03 17:16:58 +00:00

230 lines
7.4 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/>.
*
*
*/
#ifndef __COGL_CONTEXT_H
#define __COGL_CONTEXT_H
#include "cogl-internal.h"
#if HAVE_COGL_GL
#include "cogl-context-driver-gl.h"
#endif
#if HAVE_COGL_GLES || HAVE_COGL_GLES2
#include "cogl-context-driver-gles.h"
#endif
#include "cogl-context-winsys.h"
#include "cogl-primitives.h"
#include "cogl-clip-stack.h"
#include "cogl-matrix-stack.h"
#include "cogl-pipeline-private.h"
#include "cogl-buffer-private.h"
#include "cogl-bitmask.h"
#include "cogl-atlas.h"
typedef struct
{
GLfloat v[3];
GLfloat t[2];
GLubyte c[4];
} CoglTextureGLVertex;
typedef struct
{
/* Features cache */
CoglFeatureFlags feature_flags;
CoglFeatureFlagsPrivate feature_flags_private;
CoglHandle default_pipeline;
CoglHandle default_layer_0;
CoglHandle default_layer_n;
CoglHandle dummy_layer_dependant;
/* Enable cache */
unsigned long enable_flags;
gboolean enable_backface_culling;
CoglFrontWinding flushed_front_winding;
gboolean indirect;
/* A few handy matrix constants */
CoglMatrix identity_matrix;
CoglMatrix y_flip_matrix;
/* Client-side matrix stack or NULL if none */
CoglMatrixMode flushed_matrix_mode;
GArray *texture_units;
int active_texture_unit;
CoglPipelineFogState legacy_fog_state;
/* Pipelines */
CoglPipeline *opaque_color_pipeline; /* used for set_source_color */
CoglPipeline *blended_color_pipeline; /* used for set_source_color */
CoglPipeline *texture_pipeline; /* used for set_source_texture */
GString *fragment_header_buffer;
GString *fragment_source_buffer;
GList *source_stack;
int legacy_state_set;
/* Textures */
CoglHandle default_gl_texture_2d_tex;
CoglHandle default_gl_texture_rect_tex;
/* Batching geometry... */
/* We journal the texture rectangles we want to submit to OpenGL so
* we have an oppertunity to optimise the final order so that we
* can batch things together. */
GArray *journal;
GArray *logged_vertices;
GArray *journal_flush_attributes_array;
size_t journal_needed_vbo_len;
GArray *journal_clip_bounds;
GArray *polygon_vertices;
/* Some simple caching, to minimize state changes... */
CoglPipeline *current_pipeline;
unsigned long current_pipeline_changes_since_flush;
gboolean current_pipeline_skip_gl_color;
unsigned long current_pipeline_age;
GArray *pipeline0_nodes;
GArray *pipeline1_nodes;
/* Bitmask of texture coordinates arrays that are enabled */
CoglBitmask texcoord_arrays_enabled;
/* These are temporary bitmasks that are used when disabling
texcoord arrays. They are here just to avoid allocating new ones
each time */
CoglBitmask texcoord_arrays_to_disable;
CoglBitmask temp_bitmask;
gboolean gl_blend_enable_cache;
gboolean depth_test_enabled_cache;
CoglDepthTestFunction depth_test_function_cache;
gboolean depth_writing_enabled_cache;
float depth_range_near_cache;
float depth_range_far_cache;
gboolean legacy_depth_test_enabled;
float point_size_cache;
CoglBuffer *current_buffer[COGL_BUFFER_BIND_TARGET_COUNT];
/* Framebuffers */
GSList *framebuffer_stack;
CoglHandle window_buffer;
gboolean dirty_bound_framebuffer;
gboolean dirty_gl_viewport;
/* Primitives */
CoglPath *current_path;
CoglPipeline *stencil_pipeline;
/* Pre-generated VBOs containing indices to generate GL_TRIANGLES
out of a vertex array of quads */
CoglHandle quad_buffer_indices_byte;
unsigned int quad_buffer_indices_len;
CoglHandle quad_buffer_indices;
CoglIndices *rectangle_byte_indices;
CoglIndices *rectangle_short_indices;
int rectangle_short_indices_len;
gboolean in_begin_gl_block;
CoglPipeline *texture_download_pipeline;
CoglAtlas *atlas;
/* This debugging variable is used to pick a colour for visually
displaying the quad batches. It needs to be global so that it can
be reset by cogl_clear. It needs to be reset to increase the
chances of getting the same colour during an animation */
guint8 journal_rectangles_color;
/* Cached values for GL_MAX_TEXTURE_[IMAGE_]UNITS to avoid calling
glGetInteger too often */
GLint max_texture_units;
GLint max_texture_image_units;
GLint max_activateable_texture_units;
/* Fragment processing programs */
CoglHandle current_program;
CoglPipelineProgramType current_use_program_type;
GLuint current_gl_program;
/* List of types that will be considered a subclass of CoglTexture in
cogl_is_texture */
GSList *texture_types;
/* List of types that will be considered a subclass of CoglBuffer in
cogl_is_buffer */
GSList *buffer_types;
/* Clipping */
/* TRUE if we have a valid clipping stack flushed. In that case
current_clip_stack will describe what the current state is. If
this is FALSE then the current clip stack is completely unknown
so it will need to be reflushed. In that case current_clip_stack
doesn't need to be a valid pointer. We can't just use NULL in
current_clip_stack to mark a dirty state because NULL is a valid
stack (meaning no clipping) */
gboolean current_clip_stack_valid;
/* The clip state that was flushed. This isn't intended to be used
as a stack to push and pop new entries. Instead the current stack
that the user wants is part of the framebuffer state. This is
just used to record the flush state so we can avoid flushing the
same state multiple times. When the clip state is flushed this
will hold a reference */
CoglClipStack *current_clip_stack;
/* Whether the stencil buffer was used as part of the current clip
state. If TRUE then any further use of the stencil buffer (such
as for drawing paths) would need to be merged with the existing
stencil buffer */
gboolean current_clip_stack_uses_stencil;
CoglContextDriver drv;
CoglContextWinsys winsys;
} CoglContext;
CoglContext *
_cogl_context_get_default ();
/* Obtains the context and returns retval if NULL */
#define _COGL_GET_CONTEXT(ctxvar, retval) \
CoglContext *ctxvar = _cogl_context_get_default (); \
if (ctxvar == NULL) return retval;
#define NO_RETVAL
#endif /* __COGL_CONTEXT_H */