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mutter/cogl/cogl-framebuffer.h
Jasper St. Pierre e98f279712 Fix some doc issues 
Reviewed-by: Neil Roberts <neil@linux.intel.com>
2012-02-14 20:42:10 +00:00

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/*
* Cogl
*
* An object oriented GL/GLES Abstraction/Utility Layer
*
* Copyright (C) 2011 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/>.
*
*
*
* Authors:
* Robert Bragg <robert@linux.intel.com>
*/
#ifndef __COGL_FRAMEBUFFER_H
#define __COGL_FRAMEBUFFER_H
#include <cogl/cogl.h>
#include <glib.h>
#ifdef COGL_HAS_WIN32_SUPPORT
#include <windows.h>
#endif /* COGL_HAS_WIN32_SUPPORT */
#if defined (COGL_HAS_EGL_PLATFORM_WAYLAND_SUPPORT)
#include <wayland-client.h>
#endif /* COGL_HAS_EGL_PLATFORM_WAYLAND_SUPPORT */
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_to_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.
*/
#ifdef COGL_ENABLE_EXPERIMENTAL_API
#define COGL_FRAMEBUFFER(X) ((CoglFramebuffer *)(X))
/**
* 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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
float
cogl_framebuffer_get_viewport_height (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_get_viewport4fv:
* @framebuffer: A #CoglFramebuffer
* @viewport: 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
*/
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
*/
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
*/
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
*/
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
*/
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
*/
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 vertex specified by @x, @y and @z. The rotation
* follows the right-hand thumb rule so for example rotating by 10
* degrees about the vertex (0, 0, 1) causes a small counter-clockwise
* rotation.
*
* Since: 1.10
* Stability: unstable
*/
void
cogl_framebuffer_rotate (CoglFramebuffer *framebuffer,
float angle,
float x,
float y,
float z);
/**
* 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
*/
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
*/
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
*/
void
cogl_framebuffer_set_modelview_matrix (CoglFramebuffer *framebuffer,
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 wont be enough precision to identify the depth of
* objects near to each other.</note>
*
* Since: 1.10
* Stability: unstable
*/
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
*/
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: 1.0
* Stability: unstable
*/
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
*/
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
*/
void
cogl_framebuffer_set_projection_matrix (CoglFramebuffer *framebuffer,
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
*/
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
*/
void
cogl_framebuffer_push_rectangle_clip (CoglFramebuffer *framebuffer,
float x_1,
float y_1,
float x_2,
float y_2);
/**
* cogl_framebuffer_push_path_clip:
* @framebuffer: A #CoglFramebuffer pointer
* @path: The path to clip with.
*
* Sets a new clipping area using the silhouette of the specified,
* filled @path. The clipping area is intersected with the previous
* clipping area. To restore the previous clipping area, call
* cogl_framebuffer_pop_clip().
*
* Since: 1.0
* Stability: unstable
*/
void
cogl_framebuffer_push_path_clip (CoglFramebuffer *framebuffer,
CoglPath *path);
/**
* cogl_framebuffer_push_primitive_clip:
* @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 top-left corner of the primitives
* bounds
* @bounds_y2: x coordinate for the bottom-right corner of the
* primitives bounds.
* @bounds_x1: 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
*/
void
cogl_framebuffer_push_primitive_clip (CoglFramebuffer *framebuffer,
CoglPrimitive *primitive,
float bounds_x1,
float bounds_y1,
float bounds_x2,
float bounds_y2);
/**
* cogl_framebuffer_pop_clip:
* @framebuffer: A #CoglFramebuffer pointer
*
* Reverts the clipping region to the state before the last call to
* cogl_framebuffer_push_clip().
*
* Since: 1.10
* Stability: unstable
*/
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
*/
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
*/
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
*/
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
*/
int
cogl_framebuffer_get_alpha_bits (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
*/
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
*/
void
cogl_framebuffer_set_dither_enabled (CoglFramebuffer *framebuffer,
gboolean dither_enabled);
/**
* cogl_framebuffer_get_color_mask:
* @framebuffer: a pointer to a #CoglFramebuffer
*
* Gets the current #CoglColorMask of which channels would be written to the
* current framebuffer. Each bit set in the mask means that the
* corresponding color would be written.
*
* Returns: A #CoglColorMask
* Since: 1.8
* Stability: unstable
*/
CoglColorMask
cogl_framebuffer_get_color_mask (CoglFramebuffer *framebuffer);
/**
* cogl_framebuffer_set_color_mask:
* @framebuffer: a pointer to a #CoglFramebuffer
* @color_mask: A #CoglColorMask of which color channels to write to
* the current framebuffer.
*
* Defines a bit mask of which color channels should be written to the
* given @framebuffer. If a bit is set in @color_mask that means that
* color will be written.
*
* Since: 1.8
* Stability: unstable
*/
void
cogl_framebuffer_set_color_mask (CoglFramebuffer *framebuffer,
CoglColorMask color_mask);
/**
* cogl_framebuffer_get_color_format:
* @framebuffer: A #CoglFramebuffer framebuffer
*
* Queries the common #CoglPixelFormat of all color buffers attached
* to this framebuffer. For an offscreen framebuffer created with
* cogl_offscreen_new_to_texture() this will correspond to the format
* of the texture.
*
* Since: 1.8
* Stability: unstable
*/
CoglPixelFormat
cogl_framebuffer_get_color_format (CoglFramebuffer *framebuffer);
/**
* 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
*/
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
*/
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
*/
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
*/
void
cogl_framebuffer_resolve_samples_region (CoglFramebuffer *framebuffer,
int x,
int y,
int width,
int height);
/**
* @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: The #CoglContext that the given @framebuffer was
* instantiated within.
* Since: 1.8
* Stability: unstable
*/
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
*/
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
*/
void
cogl_framebuffer_clear4f (CoglFramebuffer *framebuffer,
unsigned long buffers,
float red,
float green,
float blue,
float alpha);
/**
* cogl_framebuffer_draw_primitive:
* @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 pipeline described by @pipeline.
*
* <note>This api doesn't support any of the legacy global state options such
* as cogl_set_depth_test_enabled(), cogl_set_backface_culling_enabled() or
* cogl_program_use()</note>
*
* Stability: unstable
* Since: 1.10
*/
void
cogl_framebuffer_draw_primitive (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
CoglPrimitive *primitive);
/**
* cogl_framebuffer_vdraw_attributes:
* @framebuffer: A destination #CoglFramebuffer
* @pipeline: A #CoglPipeline state object
* @mode: The #CoglVerticesMode defining the topology of vertices
* @first_vertex: The vertex offset within the given attributes to draw from
* @n_vertices: The number of vertices to draw from the given attributes
* @...: A set of vertex #CoglAttribute<!-- -->s defining vertex geometry
*
* First defines a geometry primitive by grouping a set of vertex attributes;
* specifying a @first_vertex; a number of vertices (@n_vertices) and
* specifying what kind of topology the vertices have via @mode.
*
* Then the function draws the given @primitive geometry to the specified
* destination @framebuffer using the graphics processing pipeline described by
* @pipeline.
*
* The list of #CoglAttribute<!-- -->s define the attributes of the vertices to
* be drawn, such as positions, colors and normals and should be %NULL
* terminated.
*
* Stability: unstable
* Since: 1.10
*/
void
cogl_framebuffer_vdraw_attributes (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
CoglVerticesMode mode,
int first_vertex,
int n_vertices,
...) G_GNUC_NULL_TERMINATED;
/**
* cogl_framebuffer_draw_attributes:
* @framebuffer: A destination #CoglFramebuffer
* @pipeline: A #CoglPipeline state object
* @mode: The #CoglVerticesMode defining the topology of vertices
* @first_vertex: The vertex offset within the given attributes to draw from
* @n_vertices: The number of vertices to draw from the given attributes
* @attributes: An array of pointers to #CoglAttribute<-- -->s defining vertex
* geometry
* @n_attributes: The number of attributes in the @attributes array.
*
* First defines a geometry primitive by grouping a set of vertex @attributes;
* specifying a @first_vertex; a number of vertices (@n_vertices) and
* specifying what kind of topology the vertices have via @mode.
*
* Then the function draws the given @primitive geometry to the specified
* destination @framebuffer using the graphics processing pipeline described by
* @pipeline.
*
* The list of #CoglAttribute<!-- -->s define the attributes of the vertices to
* be drawn, such as positions, colors and normals and the number of attributes
* is given as @n_attributes.
*
* <note>This api doesn't support any of the legacy global state options such
* as cogl_set_depth_test_enabled(), cogl_set_backface_culling_enabled() or
* cogl_program_use()</note>
*
* Stability: unstable
* Since: 1.10
*/
void
cogl_framebuffer_draw_attributes (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
CoglVerticesMode mode,
int first_vertex,
int n_vertices,
CoglAttribute **attributes,
int n_attributes);
/**
* cogl_framebuffer_vdraw_indexed_attributes:
* @framebuffer: A destination #CoglFramebuffer
* @pipeline: A #CoglPipeline state object
* @mode: The #CoglVerticesMode defining the topology of vertices
* @first_vertex: The vertex offset within the given attributes to draw from
* @n_vertices: The number of vertices to draw from the given attributes
* @indices: The array of indices used by the GPU to lookup attribute
* data for each vertex.
* @...: A set of vertex #CoglAttribute<!-- -->s defining vertex geometry
*
* Behaves the same as cogl_framebuffer_vdraw_attributes() except that
* instead of reading vertex data sequentially from the specified
* attributes the @indices provide an indirection for how the data
* should be indexed allowing a random access order to be
* specified.
*
* For example an indices array of [0, 1, 2, 0, 2, 3] could be used
* used to draw two triangles (@mode = %COGL_VERTICES_MODE_TRIANGLES +
* @n_vertices = 6) but only provide attribute data for the 4 corners
* of a rectangle. When the GPU needs to read in each of the 6
* vertices it will read the @indices array for each vertex in
* sequence and use the index to look up the vertex attribute data. So
* here you can see that first and fourth vertex will point to the
* same data and third and fifth vertex will also point to shared
* data.
*
* Drawing with indices can be a good way of minimizing the size of a
* mesh by allowing you to avoid data for duplicate vertices because
* multiple entries in the index array can refer back to a single
* shared vertex.
*
* <note>The @indices array must at least be as long @first_vertex +
* @n_vertices otherwise the GPU will overrun the indices array when
* looking up vertex data.</note>
*
* Since it's very common to want to draw a run of rectangles using
* indices to avoid duplicating vertex data you can use
* cogl_get_rectangle_indices() to get a set of indices that can be
* shared.
*
* <note>This api doesn't support any of the legacy global state
* options such as cogl_set_depth_test_enabled(),
* cogl_set_backface_culling_enabled() or cogl_program_use()</note>
*
* Stability: unstable
* Since: 1.10
*/
void
cogl_framebuffer_vdraw_indexed_attributes (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
CoglVerticesMode mode,
int first_vertex,
int n_vertices,
CoglIndices *indices,
...) G_GNUC_NULL_TERMINATED;
/**
* cogl_framebuffer_draw_indexed_attributes:
* @framebuffer: A destination #CoglFramebuffer
* @pipeline: A #CoglPipeline state object
* @mode: The #CoglVerticesMode defining the topology of vertices
* @first_vertex: The vertex offset within the given attributes to draw from
* @n_vertices: The number of vertices to draw from the given attributes
* @indices: The array of indices used by the GPU to lookup attribute
* data for each vertex.
* @attributes: An array of pointers to #CoglAttribute<-- -->s defining vertex
* geometry
* @n_attributes: The number of attributes in the @attributes array.
*
* Behaves the same as cogl_framebuffer_draw_attributes() except that
* instead of reading vertex data sequentially from the specified
* @attributes the @indices provide an indirection for how the data
* should be indexed allowing a random access order to be
* specified.
*
* For example an indices array of [0, 1, 2, 0, 2, 3] could be used
* used to draw two triangles (@mode = %COGL_VERTICES_MODE_TRIANGLES +
* @n_vertices = 6) but only provide attribute data for the 4 corners
* of a rectangle. When the GPU needs to read in each of the 6
* vertices it will read the @indices array for each vertex in
* sequence and use the index to look up the vertex attribute data. So
* here you can see that first and fourth vertex will point to the
* same data and third and fifth vertex will also point to shared
* data.
*
* Drawing with indices can be a good way of minimizing the size of a
* mesh by allowing you to avoid data for duplicate vertices because
* multiple entries in the index array can refer back to a single
* shared vertex.
*
* <note>The @indices array must at least be as long @first_vertex +
* @n_vertices otherwise the GPU will overrun the indices array when
* looking up vertex data.</note>
*
* Since it's very common to want to draw a run of rectangles using
* indices to avoid duplicating vertex data you can use
* cogl_get_rectangle_indices() to get a set of indices that can be
* shared.
*
* <note>This api doesn't support any of the legacy global state
* options such as cogl_set_depth_test_enabled(),
* cogl_set_backface_culling_enabled() or cogl_program_use()</note>
*
* Stability: unstable
* Since: 1.10
*/
void
cogl_framebuffer_draw_indexed_attributes (CoglFramebuffer *framebuffer,
CoglPipeline *pipeline,
CoglVerticesMode mode,
int first_vertex,
int n_vertices,
CoglIndices *indices,
CoglAttribute **attributes,
int n_attributes);
/* 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
*/
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
*/
void
cogl_framebuffer_finish (CoglFramebuffer *framebuffer);
/**
* cogl_get_draw_framebuffer:
*
* Gets the current #CoglFramebuffer as set using
* cogl_push_framebuffer()
*
* Return value: The current #CoglFramebuffer
* Stability: unstable
* Since: 1.8
*/
CoglFramebuffer *
cogl_get_draw_framebuffer (void);
#endif /* COGL_ENABLE_EXPERIMENTAL_API */
/* XXX: Note these are defined outside the COGL_ENABLE_EXPERIMENTAL_API guard since
* otherwise the glib-mkenums stuff will get upset. */
GQuark
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;
G_END_DECLS
#endif /* __COGL_FRAMEBUFFER_H */
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