mutter/cogl/cogl/cogl-framebuffer.h

1574 lines
57 KiB
C

/*
* Cogl
*
* A Low Level GPU Graphics and Utilities API
*
* Copyright (C) 2007,2008,2009,2011 Intel Corporation.
* Copyright (C) 2019 DisplayLink (UK) Ltd.
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*
*
* Authors:
* Robert Bragg <robert@linux.intel.com>
*/
#ifndef __COGL_FRAMEBUFFER_H
#define __COGL_FRAMEBUFFER_H
/* We forward declare the CoglFramebuffer type here to avoid some circular
* dependency issues with the following headers.
*/
#if defined(__COGL_H_INSIDE__) && !defined(COGL_ENABLE_MUTTER_API) && \
!defined(COGL_GIR_SCANNING)
/* For the public C api we typedef interface types as void to avoid needing
* lots of casting in code and instead we will rely on runtime type checking
* for these objects. */
typedef void CoglFramebuffer;
#else
typedef struct _CoglFramebuffer CoglFramebuffer;
#define COGL_FRAMEBUFFER(X) ((CoglFramebuffer *)(X))
#endif
#include <cogl/cogl-pipeline.h>
#include <cogl/cogl-indices.h>
#include <cogl/cogl-bitmap.h>
#include <cogl/cogl-texture.h>
#include <glib-object.h>
#include <cairo.h>
#include <graphene.h>
G_BEGIN_DECLS
/**
* SECTION:cogl-framebuffer
* @short_description: A common interface for manipulating framebuffers
*
* Framebuffers are a collection of buffers that can be rendered too.
* A framebuffer may be comprised of one or more color buffers, an
* optional depth buffer and an optional stencil buffer. Other
* configuration parameters are associated with framebuffers too such
* as whether the framebuffer supports multi-sampling (an anti-aliasing
* technique) or dithering.
*
* There are two kinds of framebuffer in Cogl, #CoglOnscreen
* framebuffers and #CoglOffscreen framebuffers. As the names imply
* offscreen framebuffers are for rendering something offscreen
* (perhaps to a texture which is bound as one of the color buffers).
* The exact semantics of onscreen framebuffers depends on the window
* system backend that you are using, but typically you can expect
* rendering to a #CoglOnscreen framebuffer will be immediately
* visible to the user.
*
* If you want to create a new framebuffer then you should start by
* looking at the #CoglOnscreen and #CoglOffscreen constructor
* functions, such as cogl_offscreen_new_with_texture() or
* cogl_onscreen_new(). The #CoglFramebuffer interface deals with
* all aspects that are common between those two types of framebuffer.
*
* Setup of a new CoglFramebuffer happens in two stages. There is a
* configuration stage where you specify all the options and ancillary
* buffers you want associated with your framebuffer and then when you
* are happy with the configuration you can "allocate" the framebuffer
* using cogl_framebuffer_allocate(). Technically explicitly calling
* cogl_framebuffer_allocate() is optional for convenience and the
* framebuffer will automatically be allocated when you first try to
* draw to it, but if you do the allocation manually then you can
* also catch any possible errors that may arise from your
* configuration.
*/
/**
* cogl_framebuffer_get_gtype:
*
* Returns: a #GType that can be used with the GLib type system.
*/
COGL_EXPORT
GType cogl_framebuffer_get_gtype (void);
/**
* cogl_framebuffer_allocate:
* @framebuffer: A #CoglFramebuffer
* @error: A pointer to a #GError for returning exceptions.
*
* Explicitly allocates a configured #CoglFramebuffer allowing developers to
* check and handle any errors that might arise from an unsupported
* configuration so that fallback configurations may be tried.
*
* <note>Many applications don't support any fallback options at least when
* they are initially developed and in that case the don't need to use this API
* since Cogl will automatically allocate a framebuffer when it first gets
* used. The disadvantage of relying on automatic allocation is that the
* program will abort with an error message if there is an error during
* automatic allocation.</note>
*
* Return value: %TRUE if there were no error allocating the framebuffer, else %FALSE.
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT gboolean
cogl_framebuffer_allocate (CoglFramebuffer *framebuffer,
GError **error);
/**
* cogl_framebuffer_get_width:
* @framebuffer: A #CoglFramebuffer
*
* Queries the current width of the given @framebuffer.
*
* Return value: The width of @framebuffer.
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT int
cogl_framebuffer_get_width (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_height:
* @framebuffer: A #CoglFramebuffer
*
* Queries the current height of the given @framebuffer.
*
* Return value: The height of @framebuffer.
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT int
cogl_framebuffer_get_height (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_set_viewport:
* @framebuffer: A #CoglFramebuffer
* @x: The top-left x coordinate of the viewport origin (only integers
* supported currently)
* @y: The top-left y coordinate of the viewport origin (only integers
* supported currently)
* @width: The width of the viewport (only integers supported currently)
* @height: The height of the viewport (only integers supported currently)
*
* Defines a scale and offset for everything rendered relative to the
* top-left of the destination framebuffer.
*
* By default the viewport has an origin of (0,0) and width and height
* that match the framebuffer's size. Assuming a default projection and
* modelview matrix then you could translate the contents of a window
* down and right by leaving the viewport size unchanged by moving the
* offset to (10,10). The viewport coordinates are measured in pixels.
* If you left the x and y origin as (0,0) you could scale the windows
* contents down by specify and width and height that's half the real
* size of the framebuffer.
*
* <note>Although the function takes floating point arguments, existing
* drivers only allow the use of integer values. In the future floating
* point values will be exposed via a checkable feature.</note>
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_set_viewport (CoglFramebuffer *framebuffer,
float x,
float y,
float width,
float height);
/**
* cogl_framebuffer_get_viewport_x:
* @framebuffer: A #CoglFramebuffer
*
* Queries the x coordinate of the viewport origin as set using cogl_framebuffer_set_viewport()
* or the default value which is 0.
*
* Return value: The x coordinate of the viewport origin.
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT float
cogl_framebuffer_get_viewport_x (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_viewport_y:
* @framebuffer: A #CoglFramebuffer
*
* Queries the y coordinate of the viewport origin as set using cogl_framebuffer_set_viewport()
* or the default value which is 0.
*
* Return value: The y coordinate of the viewport origin.
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT float
cogl_framebuffer_get_viewport_y (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_viewport_width:
* @framebuffer: A #CoglFramebuffer
*
* Queries the width of the viewport as set using cogl_framebuffer_set_viewport()
* or the default value which is the width of the framebuffer.
*
* Return value: The width of the viewport.
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT float
cogl_framebuffer_get_viewport_width (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_viewport_height:
* @framebuffer: A #CoglFramebuffer
*
* Queries the height of the viewport as set using cogl_framebuffer_set_viewport()
* or the default value which is the height of the framebuffer.
*
* Return value: The height of the viewport.
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT float
cogl_framebuffer_get_viewport_height (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_viewport4fv:
* @framebuffer: A #CoglFramebuffer
* @viewport: (out caller-allocates) (array fixed-size=4): A pointer to an
* array of 4 floats to receive the (x, y, width, height)
* components of the current viewport.
*
* Queries the x, y, width and height components of the current viewport as set
* using cogl_framebuffer_set_viewport() or the default values which are 0, 0,
* framebuffer_width and framebuffer_height. The values are written into the
* given @viewport array.
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_get_viewport4fv (CoglFramebuffer *framebuffer,
float *viewport);
/**
* cogl_framebuffer_push_matrix:
* @framebuffer: A #CoglFramebuffer pointer
*
* Copies the current model-view matrix onto the matrix stack. The matrix
* can later be restored with cogl_framebuffer_pop_matrix().
*
* Since: 1.10
*/
COGL_EXPORT void
cogl_framebuffer_push_matrix (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_pop_matrix:
* @framebuffer: A #CoglFramebuffer pointer
*
* Restores the model-view matrix on the top of the matrix stack.
*
* Since: 1.10
*/
COGL_EXPORT void
cogl_framebuffer_pop_matrix (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_identity_matrix:
* @framebuffer: A #CoglFramebuffer pointer
*
* Resets the current model-view matrix to the identity matrix.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_identity_matrix (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_scale:
* @framebuffer: A #CoglFramebuffer pointer
* @x: Amount to scale along the x-axis
* @y: Amount to scale along the y-axis
* @z: Amount to scale along the z-axis
*
* Multiplies the current model-view matrix by one that scales the x,
* y and z axes by the given values.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_scale (CoglFramebuffer *framebuffer,
float x,
float y,
float z);
/**
* cogl_framebuffer_translate:
* @framebuffer: A #CoglFramebuffer pointer
* @x: Distance to translate along the x-axis
* @y: Distance to translate along the y-axis
* @z: Distance to translate along the z-axis
*
* Multiplies the current model-view matrix by one that translates the
* model along all three axes according to the given values.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_translate (CoglFramebuffer *framebuffer,
float x,
float y,
float z);
/**
* cogl_framebuffer_rotate:
* @framebuffer: A #CoglFramebuffer pointer
* @angle: Angle in degrees to rotate.
* @x: X-component of vertex to rotate around.
* @y: Y-component of vertex to rotate around.
* @z: Z-component of vertex to rotate around.
*
* Multiplies the current model-view matrix by one that rotates the
* model around the axis-vector specified by @x, @y and @z. The
* rotation follows the right-hand thumb rule so for example rotating
* by 10 degrees about the axis-vector (0, 0, 1) causes a small
* counter-clockwise rotation.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_rotate (CoglFramebuffer *framebuffer,
float angle,
float x,
float y,
float z);
/**
* cogl_framebuffer_rotate_euler:
* @framebuffer: A #CoglFramebuffer pointer
* @euler: A #graphene_euler_t
*
* Multiplies the current model-view matrix by one that rotates
* according to the rotation described by @euler.
*
* Since: 2.0
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_rotate_euler (CoglFramebuffer *framebuffer,
const graphene_euler_t *euler);
/**
* cogl_framebuffer_transform:
* @framebuffer: A #CoglFramebuffer pointer
* @matrix: the matrix to multiply with the current model-view
*
* Multiplies the current model-view matrix by the given matrix.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_transform (CoglFramebuffer *framebuffer,
const CoglMatrix *matrix);
/**
* cogl_framebuffer_get_modelview_matrix:
* @framebuffer: A #CoglFramebuffer pointer
* @matrix: (out): return location for the model-view matrix
*
* Stores the current model-view matrix in @matrix.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_get_modelview_matrix (CoglFramebuffer *framebuffer,
CoglMatrix *matrix);
/**
* cogl_framebuffer_set_modelview_matrix:
* @framebuffer: A #CoglFramebuffer pointer
* @matrix: the new model-view matrix
*
* Sets @matrix as the new model-view matrix.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_set_modelview_matrix (CoglFramebuffer *framebuffer,
const CoglMatrix *matrix);
/**
* cogl_framebuffer_perspective:
* @framebuffer: A #CoglFramebuffer pointer
* @fov_y: Vertical field of view angle in degrees.
* @aspect: The (width over height) aspect ratio for display
* @z_near: The distance to the near clipping plane (Must be positive,
* and must not be 0)
* @z_far: The distance to the far clipping plane (Must be positive)
*
* Replaces the current projection matrix with a perspective matrix
* based on the provided values.
*
* <note>You should be careful not to have to great a @z_far / @z_near
* ratio since that will reduce the effectiveness of depth testing
* since there won't be enough precision to identify the depth of
* objects near to each other.</note>
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_perspective (CoglFramebuffer *framebuffer,
float fov_y,
float aspect,
float z_near,
float z_far);
/**
* cogl_framebuffer_frustum:
* @framebuffer: A #CoglFramebuffer pointer
* @left: X position of the left clipping plane where it
* intersects the near clipping plane
* @right: X position of the right clipping plane where it
* intersects the near clipping plane
* @bottom: Y position of the bottom clipping plane where it
* intersects the near clipping plane
* @top: Y position of the top clipping plane where it intersects
* the near clipping plane
* @z_near: The distance to the near clipping plane (Must be positive)
* @z_far: The distance to the far clipping plane (Must be positive)
*
* Replaces the current projection matrix with a perspective matrix
* for a given viewing frustum defined by 4 side clip planes that
* all cross through the origin and 2 near and far clip planes.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_frustum (CoglFramebuffer *framebuffer,
float left,
float right,
float bottom,
float top,
float z_near,
float z_far);
/**
* cogl_framebuffer_orthographic:
* @framebuffer: A #CoglFramebuffer pointer
* @x_1: The x coordinate for the first vertical clipping plane
* @y_1: The y coordinate for the first horizontal clipping plane
* @x_2: The x coordinate for the second vertical clipping plane
* @y_2: The y coordinate for the second horizontal clipping plane
* @near: The <emphasis>distance</emphasis> to the near clipping
* plane (will be <emphasis>negative</emphasis> if the plane is
* behind the viewer)
* @far: The <emphasis>distance</emphasis> to the far clipping
* plane (will be <emphasis>negative</emphasis> if the plane is
* behind the viewer)
*
* Replaces the current projection matrix with an orthographic projection
* matrix.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_orthographic (CoglFramebuffer *framebuffer,
float x_1,
float y_1,
float x_2,
float y_2,
float near,
float far);
/**
* cogl_framebuffer_get_projection_matrix:
* @framebuffer: A #CoglFramebuffer pointer
* @matrix: (out): return location for the projection matrix
*
* Stores the current projection matrix in @matrix.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_get_projection_matrix (CoglFramebuffer *framebuffer,
CoglMatrix *matrix);
/**
* cogl_framebuffer_set_projection_matrix:
* @framebuffer: A #CoglFramebuffer pointer
* @matrix: the new projection matrix
*
* Sets @matrix as the new projection matrix.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_set_projection_matrix (CoglFramebuffer *framebuffer,
const CoglMatrix *matrix);
/**
* cogl_framebuffer_push_scissor_clip:
* @framebuffer: A #CoglFramebuffer pointer
* @x: left edge of the clip rectangle in window coordinates
* @y: top edge of the clip rectangle in window coordinates
* @width: width of the clip rectangle
* @height: height of the clip rectangle
*
* Specifies a rectangular clipping area for all subsequent drawing
* operations. Any drawing commands that extend outside the rectangle
* will be clipped so that only the portion inside the rectangle will
* be displayed. The rectangle dimensions are not transformed by the
* current model-view matrix.
*
* The rectangle is intersected with the current clip region. To undo
* the effect of this function, call cogl_framebuffer_pop_clip().
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_push_scissor_clip (CoglFramebuffer *framebuffer,
int x,
int y,
int width,
int height);
/**
* cogl_framebuffer_push_rectangle_clip:
* @framebuffer: A #CoglFramebuffer pointer
* @x_1: x coordinate for top left corner of the clip rectangle
* @y_1: y coordinate for top left corner of the clip rectangle
* @x_2: x coordinate for bottom right corner of the clip rectangle
* @y_2: y coordinate for bottom right corner of the clip rectangle
*
* Specifies a modelview transformed rectangular clipping area for all
* subsequent drawing operations. Any drawing commands that extend
* outside the rectangle will be clipped so that only the portion
* inside the rectangle will be displayed. The rectangle dimensions
* are transformed by the current model-view matrix.
*
* The rectangle is intersected with the current clip region. To undo
* the effect of this function, call cogl_framebuffer_pop_clip().
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_push_rectangle_clip (CoglFramebuffer *framebuffer,
float x_1,
float y_1,
float x_2,
float y_2);
/**
* cogl_framebuffer_push_primitive_clip: (skip)
* @framebuffer: A #CoglFramebuffer pointer
* @primitive: A #CoglPrimitive describing a flat 2D shape
* @bounds_x1: x coordinate for the top-left corner of the primitives
* bounds
* @bounds_y1: y coordinate for the top-left corner of the primitives
* bounds
* @bounds_x2: x coordinate for the bottom-right corner of the
* primitives bounds.
* @bounds_y2: y coordinate for the bottom-right corner of the
* primitives bounds.
*
* Sets a new clipping area using a 2D shaped described with a
* #CoglPrimitive. The shape must not contain self overlapping
* geometry and must lie on a single 2D plane. A bounding box of the
* 2D shape in local coordinates (the same coordinates used to
* describe the shape) must be given. It is acceptable for the bounds
* to be larger than the true bounds but behaviour is undefined if the
* bounds are smaller than the true bounds.
*
* The primitive is transformed by the current model-view matrix and
* the silhouette is intersected with the previous clipping area. To
* restore the previous clipping area, call
* cogl_framebuffer_pop_clip().
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_push_primitive_clip (CoglFramebuffer *framebuffer,
CoglPrimitive *primitive,
float bounds_x1,
float bounds_y1,
float bounds_x2,
float bounds_y2);
COGL_EXPORT void
cogl_framebuffer_push_region_clip (CoglFramebuffer *framebuffer,
cairo_region_t *region);
/**
* cogl_framebuffer_pop_clip:
* @framebuffer: A #CoglFramebuffer pointer
*
* Reverts the clipping region to the state before the last call to
* cogl_framebuffer_push_scissor_clip(), cogl_framebuffer_push_rectangle_clip()
* cogl_framebuffer_push_path_clip(), or cogl_framebuffer_push_primitive_clip().
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_pop_clip (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_red_bits:
* @framebuffer: a pointer to a #CoglFramebuffer
*
* Retrieves the number of red bits of @framebuffer
*
* Return value: the number of bits
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT int
cogl_framebuffer_get_red_bits (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_green_bits:
* @framebuffer: a pointer to a #CoglFramebuffer
*
* Retrieves the number of green bits of @framebuffer
*
* Return value: the number of bits
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT int
cogl_framebuffer_get_green_bits (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_blue_bits:
* @framebuffer: a pointer to a #CoglFramebuffer
*
* Retrieves the number of blue bits of @framebuffer
*
* Return value: the number of bits
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT int
cogl_framebuffer_get_blue_bits (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_alpha_bits:
* @framebuffer: a pointer to a #CoglFramebuffer
*
* Retrieves the number of alpha bits of @framebuffer
*
* Return value: the number of bits
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT int
cogl_framebuffer_get_alpha_bits (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_depth_bits:
* @framebuffer: a pointer to a #CoglFramebuffer
*
* Retrieves the number of depth bits of @framebuffer
*
* Return value: the number of bits
*
* Since: 2.0
* Stability: unstable
*/
COGL_EXPORT int
cogl_framebuffer_get_depth_bits (CoglFramebuffer *framebuffer);
/*
* cogl_framebuffer_get_is_stereo:
* @framebuffer: a pointer to a #CoglFramebuffer
*
* Retrieves whether @framebuffer has separate left and right
* buffers for use with stereo drawing. See
* cogl_framebuffer_set_stereo_mode().
*
* Return value: %TRUE if @framebuffer has separate left and
* right buffers.
*
* Since: 1.20
* Stability: unstable
*/
COGL_EXPORT gboolean
cogl_framebuffer_get_is_stereo (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_dither_enabled:
* @framebuffer: a pointer to a #CoglFramebuffer
*
* Returns whether dithering has been requested for the given @framebuffer.
* See cogl_framebuffer_set_dither_enabled() for more details about dithering.
*
* <note>This may return %TRUE even when the underlying @framebuffer
* display pipeline does not support dithering. This value only represents
* the user's request for dithering.</note>
*
* Return value: %TRUE if dithering has been requested or %FALSE if not.
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT gboolean
cogl_framebuffer_get_dither_enabled (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_set_dither_enabled:
* @framebuffer: a pointer to a #CoglFramebuffer
* @dither_enabled: %TRUE to enable dithering or %FALSE to disable
*
* Enables or disabled dithering if supported by the hardware.
*
* Dithering is a hardware dependent technique to increase the visible
* color resolution beyond what the underlying hardware supports by playing
* tricks with the colors placed into the framebuffer to give the illusion
* of other colors. (For example this can be compared to half-toning used
* by some news papers to show varying levels of grey even though their may
* only be black and white are available).
*
* If the current display pipeline for @framebuffer does not support dithering
* then this has no affect.
*
* Dithering is enabled by default.
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_set_dither_enabled (CoglFramebuffer *framebuffer,
gboolean dither_enabled);
/**
* cogl_framebuffer_get_depth_write_enabled:
* @framebuffer: a pointer to a #CoglFramebuffer
*
* Queries whether depth buffer writing is enabled for @framebuffer. This
* can be controlled via cogl_framebuffer_set_depth_write_enabled().
*
* Return value: %TRUE if depth writing is enabled or %FALSE if not.
* Since: 1.18
* Stability: unstable
*/
COGL_EXPORT gboolean
cogl_framebuffer_get_depth_write_enabled (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_set_depth_write_enabled:
* @framebuffer: a pointer to a #CoglFramebuffer
* @depth_write_enabled: %TRUE to enable depth writing or %FALSE to disable
*
* Enables or disables depth buffer writing when rendering to @framebuffer.
* If depth writing is enabled for both the framebuffer and the rendering
* pipeline, and the framebuffer has an associated depth buffer, depth
* information will be written to this buffer during rendering.
*
* Depth buffer writing is enabled by default.
*
* Since: 1.18
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_set_depth_write_enabled (CoglFramebuffer *framebuffer,
gboolean depth_write_enabled);
/**
* cogl_framebuffer_get_stereo_mode:
* @framebuffer: a pointer to a #CoglFramebuffer
*
* Gets the current #CoglStereoMode, which defines which stereo buffers
* should be drawn to. See cogl_framebuffer_set_stereo_mode().
*
* Returns: A #CoglStereoMode
* Since: 1.20
* Stability: unstable
*/
COGL_EXPORT CoglStereoMode
cogl_framebuffer_get_stereo_mode (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_set_stereo_mode:
* @framebuffer: a pointer to a #CoglFramebuffer
* @stereo_mode: A #CoglStereoMode specifying which stereo buffers
* should be drawn tow.
*
* Sets which stereo buffers should be drawn to. The default
* is %COGL_STEREO_BOTH, which means that both the left and
* right buffers will be affected by drawing. For this to have
* an effect, the display system must support stereo drawables,
* and the framebuffer must have been created with stereo
* enabled. (See cogl_onscreen_template_set_stereo_enabled(),
* cogl_framebuffer_get_is_stereo().)
*
* Since: 1.20
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_set_stereo_mode (CoglFramebuffer *framebuffer,
CoglStereoMode stereo_mode);
/**
* cogl_framebuffer_set_samples_per_pixel:
* @framebuffer: A #CoglFramebuffer framebuffer
* @samples_per_pixel: The minimum number of samples per pixel
*
* Requires that when rendering to @framebuffer then @n point samples
* should be made per pixel which will all contribute to the final
* resolved color for that pixel. The idea is that the hardware aims
* to get quality similar to what you would get if you rendered
* everything twice as big (for 4 samples per pixel) and then scaled
* that image back down with filtering. It can effectively remove the
* jagged edges of polygons and should be more efficient than if you
* were to manually render at a higher resolution and downscale
* because the hardware is often able to take some shortcuts. For
* example the GPU may only calculate a single texture sample for all
* points of a single pixel, and for tile based architectures all the
* extra sample data (such as depth and stencil samples) may be
* handled on-chip and so avoid increased demand on system memory
* bandwidth.
*
* By default this value is usually set to 0 and that is referred to
* as "single-sample" rendering. A value of 1 or greater is referred
* to as "multisample" rendering.
*
* <note>There are some semantic differences between single-sample
* rendering and multisampling with just 1 point sample such as it
* being redundant to use the cogl_framebuffer_resolve_samples() and
* cogl_framebuffer_resolve_samples_region() apis with single-sample
* rendering.</note>
*
* <note>It's recommended that
* cogl_framebuffer_resolve_samples_region() be explicitly used at the
* end of rendering to a point sample buffer to minimize the number of
* samples that get resolved. By default Cogl will implicitly resolve
* all framebuffer samples but if only a small region of a
* framebuffer has changed this can lead to redundant work being
* done.</note>
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_set_samples_per_pixel (CoglFramebuffer *framebuffer,
int samples_per_pixel);
/**
* cogl_framebuffer_get_samples_per_pixel:
* @framebuffer: A #CoglFramebuffer framebuffer
*
* Gets the number of points that are sampled per-pixel when
* rasterizing geometry. Usually by default this will return 0 which
* means that single-sample not multisample rendering has been chosen.
* When using a GPU supporting multisample rendering it's possible to
* increase the number of samples per pixel using
* cogl_framebuffer_set_samples_per_pixel().
*
* Calling cogl_framebuffer_get_samples_per_pixel() before the
* framebuffer has been allocated will simply return the value set
* using cogl_framebuffer_set_samples_per_pixel(). After the
* framebuffer has been allocated the value will reflect the actual
* number of samples that will be made by the GPU.
*
* Returns: The number of point samples made per pixel when
* rasterizing geometry or 0 if single-sample rendering
* has been chosen.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT int
cogl_framebuffer_get_samples_per_pixel (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_resolve_samples:
* @framebuffer: A #CoglFramebuffer framebuffer
*
* When point sample rendering (also known as multisample rendering)
* has been enabled via cogl_framebuffer_set_samples_per_pixel()
* then you can optionally call this function (or
* cogl_framebuffer_resolve_samples_region()) to explicitly resolve
* the point samples into values for the final color buffer.
*
* Some GPUs will implicitly resolve the point samples during
* rendering and so this function is effectively a nop, but with other
* architectures it is desirable to defer the resolve step until the
* end of the frame.
*
* Since Cogl will automatically ensure samples are resolved if the
* target color buffer is used as a source this API only needs to be
* used if explicit control is desired - perhaps because you want to
* ensure that the resolve is completed in advance to avoid later
* having to wait for the resolve to complete.
*
* If you are performing incremental updates to a framebuffer you
* should consider using cogl_framebuffer_resolve_samples_region()
* instead to avoid resolving redundant pixels.
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_resolve_samples (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_resolve_samples_region:
* @framebuffer: A #CoglFramebuffer framebuffer
* @x: top-left x coordinate of region to resolve
* @y: top-left y coordinate of region to resolve
* @width: width of region to resolve
* @height: height of region to resolve
*
* When point sample rendering (also known as multisample rendering)
* has been enabled via cogl_framebuffer_set_samples_per_pixel()
* then you can optionally call this function (or
* cogl_framebuffer_resolve_samples()) to explicitly resolve the point
* samples into values for the final color buffer.
*
* Some GPUs will implicitly resolve the point samples during
* rendering and so this function is effectively a nop, but with other
* architectures it is desirable to defer the resolve step until the
* end of the frame.
*
* Use of this API is recommended if incremental, small updates to
* a framebuffer are being made because by default Cogl will
* implicitly resolve all the point samples of the framebuffer which
* can result in redundant work if only a small number of samples have
* changed.
*
* Because some GPUs implicitly resolve point samples this function
* only guarantees that at-least the region specified will be resolved
* and if you have rendered to a larger region then it's possible that
* other samples may be implicitly resolved.
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_resolve_samples_region (CoglFramebuffer *framebuffer,
int x,
int y,
int width,
int height);
/**
* cogl_framebuffer_get_context:
* @framebuffer: A #CoglFramebuffer
*
* Can be used to query the #CoglContext a given @framebuffer was
* instantiated within. This is the #CoglContext that was passed to
* cogl_onscreen_new() for example.
*
* Return value: (transfer none): The #CoglContext that the given
* @framebuffer was instantiated within.
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT CoglContext *
cogl_framebuffer_get_context (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_clear:
* @framebuffer: A #CoglFramebuffer
* @buffers: A mask of #CoglBufferBit<!-- -->'s identifying which auxiliary
* buffers to clear
* @color: The color to clear the color buffer too if specified in
* @buffers.
*
* Clears all the auxiliary buffers identified in the @buffers mask, and if
* that includes the color buffer then the specified @color is used.
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_clear (CoglFramebuffer *framebuffer,
unsigned long buffers,
const CoglColor *color);
/**
* cogl_framebuffer_clear4f:
* @framebuffer: A #CoglFramebuffer
* @buffers: A mask of #CoglBufferBit<!-- -->'s identifying which auxiliary
* buffers to clear
* @red: The red component of color to clear the color buffer too if
* specified in @buffers.
* @green: The green component of color to clear the color buffer too if
* specified in @buffers.
* @blue: The blue component of color to clear the color buffer too if
* specified in @buffers.
* @alpha: The alpha component of color to clear the color buffer too if
* specified in @buffers.
*
* Clears all the auxiliary buffers identified in the @buffers mask, and if
* that includes the color buffer then the specified @color is used.
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_clear4f (CoglFramebuffer *framebuffer,
unsigned long buffers,
float red,
float green,
float blue,
float alpha);
/**
* cogl_framebuffer_draw_primitive: (skip)
* @framebuffer: A destination #CoglFramebuffer
* @pipeline: A #CoglPipeline state object
* @primitive: A #CoglPrimitive geometry object
*
* Draws the given @primitive geometry to the specified destination
* @framebuffer using the graphics processing state described by @pipeline.
*
* This drawing api doesn't support high-level meta texture types such
* as #CoglTexture2DSliced so it is the user's responsibility to
* ensure that only low-level textures that can be directly sampled by
* a GPU such as #CoglTexture2D are associated with layers of the given
* @pipeline.
*
* <note>This api doesn't support any of the legacy global state options such
* as cogl_set_depth_test_enabled() or
* cogl_set_backface_culling_enabled().</note>
*
* Stability: unstable
* Since: 1.10
* Deprecated: 1.16: Use #CoglPrimitive<!-- -->s and
* cogl_primitive_draw() instead
*/
COGL_DEPRECATED_FOR (cogl_primitive_draw)
COGL_EXPORT void
cogl_framebuffer_draw_primitive (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
CoglPrimitive *primitive);
/**
* cogl_framebuffer_draw_rectangle:
* @framebuffer: A destination #CoglFramebuffer
* @pipeline: A #CoglPipeline state object
* @x_1: X coordinate of the top-left corner
* @y_1: Y coordinate of the top-left corner
* @x_2: X coordinate of the bottom-right corner
* @y_2: Y coordinate of the bottom-right corner
*
* Draws a rectangle to @framebuffer with the given @pipeline state
* and with the top left corner positioned at (@x_1, @y_1) and the
* bottom right corner positioned at (@x_2, @y_2).
*
* <note>The position is the position before the rectangle has been
* transformed by the model-view matrix and the projection
* matrix.</note>
*
* <note>If you want to describe a rectangle with a texture mapped on
* it then you can use
* cogl_framebuffer_draw_textured_rectangle().</note>
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_draw_rectangle (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
float x_1,
float y_1,
float x_2,
float y_2);
/**
* cogl_framebuffer_draw_textured_rectangle:
* @framebuffer: A destination #CoglFramebuffer
* @pipeline: A #CoglPipeline state object
* @x_1: x coordinate upper left on screen.
* @y_1: y coordinate upper left on screen.
* @x_2: x coordinate lower right on screen.
* @y_2: y coordinate lower right on screen.
* @s_1: S texture coordinate of the top-left coorner
* @t_1: T texture coordinate of the top-left coorner
* @s_2: S texture coordinate of the bottom-right coorner
* @t_2: T texture coordinate of the bottom-right coorner
*
* Draws a textured rectangle to @framebuffer using the given
* @pipeline state with the top left corner positioned at (@x_1, @y_1)
* and the bottom right corner positioned at (@x_2, @y_2). The top
* left corner will have texture coordinates of (@s_1, @t_1) and the
* bottom right corner will have texture coordinates of (@s_2, @t_2).
*
* <note>The position is the position before the rectangle has been
* transformed by the model-view matrix and the projection
* matrix.</note>
*
* This is a high level drawing api that can handle any kind of
* #CoglMetaTexture texture such as #CoglTexture2DSliced textures
* which may internally be comprised of multiple low-level textures.
* This is unlike low-level drawing apis such as cogl_primitive_draw()
* which only support low level texture types that are directly
* supported by GPUs such as #CoglTexture2D.
*
* <note>The given texture coordinates will only be used for the first
* texture layer of the pipeline and if your pipeline has more than
* one layer then all other layers will have default texture
* coordinates of @s_1=0.0 @t_1=0.0 @s_2=1.0 @t_2=1.0 </note>
*
* The given texture coordinates should always be normalized such that
* (0, 0) corresponds to the top left and (1, 1) corresponds to the
* bottom right. To map an entire texture across the rectangle pass
* in @s_1=0, @t_1=0, @s_2=1, @t_2=1.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_draw_textured_rectangle (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
float x_1,
float y_1,
float x_2,
float y_2,
float s_1,
float t_1,
float s_2,
float t_2);
/**
* cogl_framebuffer_draw_multitextured_rectangle:
* @framebuffer: A destination #CoglFramebuffer
* @pipeline: A #CoglPipeline state object
* @x_1: x coordinate upper left on screen.
* @y_1: y coordinate upper left on screen.
* @x_2: x coordinate lower right on screen.
* @y_2: y coordinate lower right on screen.
* @tex_coords: (in) (array) (transfer none): An array containing groups of
* 4 float values: [s_1, t_1, s_2, t_2] that are interpreted as two texture
* coordinates; one for the top left texel, and one for the bottom right
* texel. Each value should be between 0.0 and 1.0, where the coordinate
* (0.0, 0.0) represents the top left of the texture, and (1.0, 1.0) the
* bottom right.
* @tex_coords_len: The length of the @tex_coords array. (For one layer
* and one group of texture coordinates, this would be 4)
*
* Draws a textured rectangle to @framebuffer with the given @pipeline
* state with the top left corner positioned at (@x_1, @y_1) and the
* bottom right corner positioned at (@x_2, @y_2). As a pipeline may
* contain multiple texture layers this interface lets you supply
* texture coordinates for each layer of the pipeline.
*
* <note>The position is the position before the rectangle has been
* transformed by the model-view matrix and the projection
* matrix.</note>
*
* This is a high level drawing api that can handle any kind of
* #CoglMetaTexture texture for the first layer such as
* #CoglTexture2DSliced textures which may internally be comprised of
* multiple low-level textures. This is unlike low-level drawing apis
* such as cogl_primitive_draw() which only support low level texture
* types that are directly supported by GPUs such as #CoglTexture2D.
*
* <note>This api can not currently handle multiple high-level meta
* texture layers. The first layer may be a high level meta texture
* such as #CoglTexture2DSliced but all other layers much be low
* level textures such as #CoglTexture2D.
*
* The top left texture coordinate for layer 0 of any pipeline will be
* (tex_coords[0], tex_coords[1]) and the bottom right coordinate will
* be (tex_coords[2], tex_coords[3]). The coordinates for layer 1
* would be (tex_coords[4], tex_coords[5]) (tex_coords[6],
* tex_coords[7]) and so on...
*
* The given texture coordinates should always be normalized such that
* (0, 0) corresponds to the top left and (1, 1) corresponds to the
* bottom right. To map an entire texture across the rectangle pass
* in tex_coords[0]=0, tex_coords[1]=0, tex_coords[2]=1,
* tex_coords[3]=1.
*
* The first pair of coordinates are for the first layer (with the
* smallest layer index) and if you supply less texture coordinates
* than there are layers in the current source material then default
* texture coordinates (0.0, 0.0, 1.0, 1.0) are generated.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_draw_multitextured_rectangle (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
float x_1,
float y_1,
float x_2,
float y_2,
const float *tex_coords,
int tex_coords_len);
/**
* cogl_framebuffer_draw_rectangles:
* @framebuffer: A destination #CoglFramebuffer
* @pipeline: A #CoglPipeline state object
* @coordinates: (in) (array) (transfer none): an array of coordinates
* containing groups of 4 float values: [x_1, y_1, x_2, y_2] that are
* interpreted as two position coordinates; one for the top left of
* the rectangle (x1, y1), and one for the bottom right of the
* rectangle (x2, y2).
* @n_rectangles: number of rectangles defined in @coordinates.
*
* Draws a series of rectangles to @framebuffer with the given
* @pipeline state in the same way that
* cogl_framebuffer_draw_rectangle() does.
*
* The top left corner of the first rectangle is positioned at
* (coordinates[0], coordinates[1]) and the bottom right corner is
* positioned at (coordinates[2], coordinates[3]). The positions for
* the second rectangle are (coordinates[4], coordinates[5]) and
* (coordinates[6], coordinates[7]) and so on...
*
* <note>The position is the position before the rectangle has been
* transformed by the model-view matrix and the projection
* matrix.</note>
*
* As a general rule for better performance its recommended to use
* this this API instead of calling
* cogl_framebuffer_draw_textured_rectangle() separately for multiple
* rectangles if all of the rectangles will be drawn together with the
* same @pipeline state.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_draw_rectangles (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
const float *coordinates,
unsigned int n_rectangles);
/**
* cogl_framebuffer_draw_textured_rectangles:
* @framebuffer: A destination #CoglFramebuffer
* @pipeline: A #CoglPipeline state object
* @coordinates: (in) (array) (transfer none): an array containing
* groups of 8 float values: [x_1, y_1, x_2, y_2, s_1, t_1, s_2, t_2]
* that have the same meaning as the arguments for
* cogl_framebuffer_draw_textured_rectangle().
* @n_rectangles: number of rectangles to @coordinates to draw
*
* Draws a series of rectangles to @framebuffer with the given
* @pipeline state in the same way that
* cogl_framebuffer_draw_textured_rectangle() does.
*
* <note>The position is the position before the rectangle has been
* transformed by the model-view matrix and the projection
* matrix.</note>
*
* This is a high level drawing api that can handle any kind of
* #CoglMetaTexture texture such as #CoglTexture2DSliced textures
* which may internally be comprised of multiple low-level textures.
* This is unlike low-level drawing apis such as cogl_primitive_draw()
* which only support low level texture types that are directly
* supported by GPUs such as #CoglTexture2D.
*
* The top left corner of the first rectangle is positioned at
* (coordinates[0], coordinates[1]) and the bottom right corner is
* positioned at (coordinates[2], coordinates[3]). The top left
* texture coordinate is (coordinates[4], coordinates[5]) and the
* bottom right texture coordinate is (coordinates[6],
* coordinates[7]). The coordinates for subsequent rectangles
* are defined similarly by the subsequent coordinates.
*
* As a general rule for better performance its recommended to use
* this this API instead of calling
* cogl_framebuffer_draw_textured_rectangle() separately for multiple
* rectangles if all of the rectangles will be drawn together with the
* same @pipeline state.
*
* The given texture coordinates should always be normalized such that
* (0, 0) corresponds to the top left and (1, 1) corresponds to the
* bottom right. To map an entire texture across the rectangle pass
* in tex_coords[0]=0, tex_coords[1]=0, tex_coords[2]=1,
* tex_coords[3]=1.
*
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_draw_textured_rectangles (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
const float *coordinates,
unsigned int n_rectangles);
/* XXX: Should we take an n_buffers + buffer id array instead of using
* the CoglBufferBits type which doesn't seem future proof? */
/**
* cogl_framebuffer_discard_buffers:
* @framebuffer: A #CoglFramebuffer
* @buffers: A #CoglBufferBit mask of which ancillary buffers you want
* to discard.
*
* Declares that the specified @buffers no longer need to be referenced
* by any further rendering commands. This can be an important
* optimization to avoid subsequent frames of rendering depending on
* the results of a previous frame.
*
* For example; some tile-based rendering GPUs are able to avoid allocating and
* accessing system memory for the depth and stencil buffer so long as these
* buffers are not required as input for subsequent frames and that can save a
* significant amount of memory bandwidth used to save and restore their
* contents to system memory between frames.
*
* It is currently considered an error to try and explicitly discard the color
* buffer by passing %COGL_BUFFER_BIT_COLOR. This is because the color buffer is
* already implicitly discard when you finish rendering to a #CoglOnscreen
* framebuffer, and it's not meaningful to try and discard the color buffer of
* a #CoglOffscreen framebuffer since they are single-buffered.
*
*
* Since: 1.8
* Stability: unstable
*/
COGL_EXPORT void
cogl_framebuffer_discard_buffers (CoglFramebuffer *framebuffer,
unsigned long buffers);
/**
* cogl_framebuffer_finish:
* @framebuffer: A #CoglFramebuffer pointer
*
* This blocks the CPU until all pending rendering associated with the
* specified framebuffer has completed. It's very rare that developers should
* ever need this level of synchronization with the GPU and should never be
* used unless you clearly understand why you need to explicitly force
* synchronization.
*
* One example might be for benchmarking purposes to be sure timing
* measurements reflect the time that the GPU is busy for not just the time it
* takes to queue rendering commands.
*
* Stability: unstable
* Since: 1.10
*/
COGL_EXPORT void
cogl_framebuffer_finish (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_read_pixels_into_bitmap:
* @framebuffer: A #CoglFramebuffer
* @x: The x position to read from
* @y: The y position to read from
* @source: Identifies which auxiliary buffer you want to read
* (only COGL_READ_PIXELS_COLOR_BUFFER supported currently)
* @bitmap: The bitmap to store the results in.
*
* This reads a rectangle of pixels from the given framebuffer where
* position (0, 0) is the top left. The pixel at (x, y) is the first
* read, and a rectangle of pixels with the same size as the bitmap is
* read right and downwards from that point.
*
* Currently Cogl assumes that the framebuffer is in a premultiplied
* format so if the format of @bitmap is non-premultiplied it will
* convert it. To read the pixel values without any conversion you
* should either specify a format that doesn't use an alpha channel or
* use one of the formats ending in PRE.
*
* Return value: %TRUE if the read succeeded or %FALSE otherwise. The
* function is only likely to fail if the bitmap points to a pixel
* buffer and it could not be mapped.
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT gboolean
cogl_framebuffer_read_pixels_into_bitmap (CoglFramebuffer *framebuffer,
int x,
int y,
CoglReadPixelsFlags source,
CoglBitmap *bitmap);
/**
* cogl_framebuffer_read_pixels:
* @framebuffer: A #CoglFramebuffer
* @x: The x position to read from
* @y: The y position to read from
* @width: The width of the region of rectangles to read
* @height: The height of the region of rectangles to read
* @format: The pixel format to store the data in
* @pixels: The address of the buffer to store the data in
*
* This is a convenience wrapper around
* cogl_framebuffer_read_pixels_into_bitmap() which allocates a
* temporary #CoglBitmap to read pixel data directly into the given
* buffer. The rowstride of the buffer is assumed to be the width of
* the region times the bytes per pixel of the format. The source for
* the data is always taken from the color buffer. If you want to use
* any other rowstride or source, please use the
* cogl_framebuffer_read_pixels_into_bitmap() function directly.
*
* The implementation of the function looks like this:
*
* |[
* bitmap = cogl_bitmap_new_for_data (context,
* width, height,
* format,
* /<!-- -->* rowstride *<!-- -->/
* bpp * width,
* pixels);
* cogl_framebuffer_read_pixels_into_bitmap (framebuffer,
* x, y,
* COGL_READ_PIXELS_COLOR_BUFFER,
* bitmap);
* cogl_object_unref (bitmap);
* ]|
*
* Return value: %TRUE if the read succeeded or %FALSE otherwise.
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT gboolean
cogl_framebuffer_read_pixels (CoglFramebuffer *framebuffer,
int x,
int y,
int width,
int height,
CoglPixelFormat format,
uint8_t *pixels);
COGL_EXPORT uint32_t
cogl_framebuffer_error_quark (void);
/**
* COGL_FRAMEBUFFER_ERROR:
*
* An error domain for reporting #CoglFramebuffer exceptions
*/
#define COGL_FRAMEBUFFER_ERROR (cogl_framebuffer_error_quark ())
typedef enum /*< prefix=COGL_FRAMEBUFFER_ERROR >*/
{
COGL_FRAMEBUFFER_ERROR_ALLOCATE
} CoglFramebufferError;
/**
* cogl_is_framebuffer:
* @object: A #CoglObject pointer
*
* Gets whether the given object references a #CoglFramebuffer.
*
* Return value: %TRUE if the object references a #CoglFramebuffer
* and %FALSE otherwise.
* Since: 1.10
* Stability: unstable
*/
COGL_EXPORT gboolean
cogl_is_framebuffer (void *object);
/**
* cogl_blit_framebuffer:
* @src: The source #CoglFramebuffer
* @dest: The destination #CoglFramebuffer
* @src_x: Source x position
* @src_y: Source y position
* @dst_x: Destination x position
* @dst_y: Destination y position
* @width: Width of region to copy
* @height: Height of region to copy
* @error: optional error object
*
* @return FALSE for an immediately detected error, TRUE otherwise.
*
* This blits a region of the color buffer of the source buffer
* to the destination buffer. This function should only be
* called if the COGL_FEATURE_ID_BLIT_FRAMEBUFFER feature is
* advertised.
*
* The source and destination rectangles are defined in offscreen
* framebuffer orientation. When copying between an offscreen and
* onscreen framebuffers, the image is y-flipped accordingly.
*
* The two buffers must have the same value types (e.g. floating-point,
* unsigned int, signed int, or fixed-point), but color formats do not
* need to match. This limitation comes from OpenGL ES 3.0 definition
* of glBlitFramebuffer.
*
* Note that this function differs a lot from the glBlitFramebuffer
* function provided by the GL_EXT_framebuffer_blit extension. Notably
* it doesn't support having different sizes for the source and
* destination rectangle. This doesn't seem
* like a particularly useful feature. If the application wanted to
* scale the results it may make more sense to draw a primitive
* instead.
*
* The GL function is documented to be affected by the scissor. This
* function therefore ensure that an empty clip stack is flushed
* before performing the blit which means the scissor is effectively
* ignored.
*
* The function also doesn't support specifying the buffers to copy
* and instead only the color buffer is copied. When copying the depth
* or stencil buffers the extension on GLES2.0 only supports copying
* the full buffer which would be awkward to document with this
* API. If we wanted to support that feature it may be better to have
* a separate function to copy the entire buffer for a given mask.
*
* The @c error argument is optional, it can be NULL. If it is not NULL
* and this function returns FALSE, an error object with a code from
* COGL_SYSTEM_ERROR will be created.
*/
COGL_EXPORT gboolean
cogl_blit_framebuffer (CoglFramebuffer *src,
CoglFramebuffer *dest,
int src_x,
int src_y,
int dst_x,
int dst_y,
int width,
int height,
GError **error);
/**
* cogl_framebuffer_flush:
* @framebuffer: A #CoglFramebuffer pointer
*
* Flushes @framebuffer to ensure the current batch of commands is
* submitted to the GPU.
*
* Unlike cogl_framebuffer_finish(), this does not block the CPU.
*/
void
cogl_framebuffer_flush (CoglFramebuffer *framebuffer);
G_END_DECLS
#endif /* __COGL_FRAMEBUFFER_H */