mirror of
https://github.com/brl/mutter.git
synced 2024-11-25 09:30:45 -05:00
df07edf83e
This adds a clarification that cogl_vertex_buffer_add can also be used to replace a previously added attribute with the same name.
410 lines
14 KiB
C
410 lines
14 KiB
C
/*
|
|
* Cogl
|
|
*
|
|
* An object oriented GL/GLES Abstraction/Utility Layer
|
|
*
|
|
* Copyright (C) 2008,2009 Intel Corporation.
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2 of the License, or (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
|
|
*
|
|
*
|
|
*
|
|
* Authors:
|
|
* Robert Bragg <robert@linux.intel.com>
|
|
*/
|
|
|
|
#if !defined(__COGL_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
|
|
#error "Only <cogl/cogl.h> can be included directly."
|
|
#endif
|
|
|
|
#ifndef __COGL_VERTEX_BUFFER_H__
|
|
#define __COGL_VERTEX_BUFFER_H__
|
|
|
|
#include <glib.h>
|
|
#include <cogl/cogl-defines.h>
|
|
#include <cogl/cogl-types.h>
|
|
|
|
G_BEGIN_DECLS
|
|
|
|
/**
|
|
* SECTION:cogl-vertex-buffer
|
|
* @short_description: An API for submitting extensible arrays of vertex
|
|
* attributes to be mapped into the GPU for fast drawing.
|
|
*
|
|
* For example to describe a textured triangle, you could create a new cogl
|
|
* vertex buffer with 3 vertices, and then you might add 2 attributes for each
|
|
* vertex:
|
|
* <orderedlist>
|
|
* <listitem>
|
|
* a "gl_Position" describing the (x,y,z) position for each vertex.
|
|
* </listitem>
|
|
* <listitem>
|
|
* a "gl_MultiTexCoord0" describing the (tx,ty) texture coordinates for each
|
|
* vertex.
|
|
* </listitem>
|
|
* </orderedlist>
|
|
*
|
|
* The Vertex Buffer API is designed to be a fairly raw mechanism for
|
|
* developers to be able to submit geometry to Cogl in a format that can be
|
|
* directly consumed by an OpenGL driver and mapped into your GPU for fast
|
|
* re-use. It is designed to avoid repeated validation of the attributes by the
|
|
* driver; to minimize transport costs (e.g. considering indirect GLX
|
|
* use-cases) and to potentially avoid repeated format conversions when
|
|
* attributes are supplied in a format that is not natively supported by the
|
|
* GPU.
|
|
*
|
|
* Although this API does allow you to modify attributes after they have been
|
|
* submitted to the GPU you should be aware that modification is not that
|
|
* cheap, since it implies validating the new data and potentially the
|
|
* OpenGL driver will need to reformat it for the GPU.
|
|
*
|
|
* If at all possible think of tricks that let you re-use static attributes,
|
|
* and if you do need to repeatedly update attributes (e.g. for some kind of
|
|
* morphing geometry) then only update and re-submit the specific attributes
|
|
* that have changed.
|
|
*/
|
|
|
|
/**
|
|
* cogl_vertex_buffer_new:
|
|
* @n_vertices: The number of vertices that your attributes will correspond to.
|
|
*
|
|
* Creates a new vertex buffer that you can use to add attributes.
|
|
*
|
|
* Return value: a new #CoglHandle
|
|
*/
|
|
CoglHandle
|
|
cogl_vertex_buffer_new (unsigned int n_vertices);
|
|
|
|
/**
|
|
* cogl_vertex_buffer_get_n_vertices:
|
|
* @handle: A vertex buffer handle
|
|
*
|
|
* Retrieves the number of vertices that @handle represents
|
|
*
|
|
* Return value: the number of vertices
|
|
*/
|
|
unsigned int
|
|
cogl_vertex_buffer_get_n_vertices (CoglHandle handle);
|
|
|
|
/**
|
|
* cogl_vertex_buffer_add:
|
|
* @handle: A vertex buffer handle
|
|
* @attribute_name: The name of your attribute. It should be a valid GLSL
|
|
* variable name and standard attribute types must use one of following
|
|
* built-in names: (Note: they correspond to the built-in names of GLSL)
|
|
* <itemizedlist>
|
|
* <listitem>"gl_Color"</listitem>
|
|
* <listitem>"gl_Normal"</listitem>
|
|
* <listitem>"gl_MultiTexCoord0, gl_MultiTexCoord1, ..."</listitem>
|
|
* <listitem>"gl_Vertex"</listitem>
|
|
* </itemizedlist>
|
|
* To support adding multiple variations of the same attribute the name
|
|
* can have a detail component, E.g. "gl_Color::active" or
|
|
* "gl_Color::inactive"
|
|
* @n_components: The number of components per attribute and must be 1, 2,
|
|
* 3 or 4
|
|
* @type: a #CoglAttributeType specifying the data type of each component.
|
|
* @normalized: If %TRUE, this specifies that values stored in an integer
|
|
* format should be mapped into the range [-1.0, 1.0] or [0.0, 1.0]
|
|
* for unsigned values. If %FALSE they are converted to floats
|
|
* directly.
|
|
* @stride: This specifies the number of bytes from the start of one attribute
|
|
* value to the start of the next value (for the same attribute). So, for
|
|
* example, with a position interleved with color like this:
|
|
* XYRGBAXYRGBAXYRGBA, then if each letter represents a byte, the
|
|
* stride for both attributes is 6. The special value 0 means the
|
|
* values are stored sequentially in memory.
|
|
* @pointer: This addresses the first attribute in the vertex array. This
|
|
* must remain valid until you either call cogl_vertex_buffer_submit() or
|
|
* issue a draw call.
|
|
*
|
|
* Adds an attribute to a buffer, or replaces a previously added
|
|
* attribute with the same name.
|
|
*
|
|
* You either can use one of the built-in names such as "gl_Vertex", or
|
|
* "gl_MultiTexCoord0" to add standard attributes, like positions, colors
|
|
* and normals, or you can add custom attributes for use in shaders.
|
|
*
|
|
* The number of vertices declared when calling cogl_vertex_buffer_new()
|
|
* determines how many attribute values will be read from the supplied
|
|
* @pointer.
|
|
*
|
|
* The data for your attribute isn't copied anywhere until you call
|
|
* cogl_vertex_buffer_submit(), or issue a draw call which automatically
|
|
* submits pending attribute changes. so the supplied pointer must remain
|
|
* valid until then. If you are updating an existing attribute (done by
|
|
* re-adding it) then you still need to re-call cogl_vertex_buffer_submit()
|
|
* to commit the changes to the GPU. Be carefull to minimize the number
|
|
* of calls to cogl_vertex_buffer_submit(), though.
|
|
*
|
|
* <note>If you are interleving attributes it is assumed that each interleaved
|
|
* attribute starts no farther than +- stride bytes from the other attributes
|
|
* it is interleved with. I.e. this is ok:
|
|
* <programlisting>
|
|
* |-0-0-0-0-0-0-0-0-0-0|
|
|
* </programlisting>
|
|
* This is not ok:
|
|
* <programlisting>
|
|
* |- - - - -0-0-0-0-0-0 0 0 0 0|
|
|
* </programlisting>
|
|
* (Though you can have multiple groups of interleved attributes)</note>
|
|
*/
|
|
void
|
|
cogl_vertex_buffer_add (CoglHandle handle,
|
|
const char *attribute_name,
|
|
guint8 n_components,
|
|
CoglAttributeType type,
|
|
gboolean normalized,
|
|
guint16 stride,
|
|
const void *pointer);
|
|
|
|
/**
|
|
* cogl_vertex_buffer_delete:
|
|
* @handle: A vertex buffer handle
|
|
* @attribute_name: The name of a previously added attribute
|
|
*
|
|
* Deletes an attribute from a buffer. You will need to call
|
|
* cogl_vertex_buffer_submit() or issue a draw call to commit this
|
|
* change to the GPU.
|
|
*/
|
|
void
|
|
cogl_vertex_buffer_delete (CoglHandle handle,
|
|
const char *attribute_name);
|
|
|
|
/**
|
|
* cogl_vertex_buffer_submit:
|
|
* @handle: A vertex buffer handle
|
|
*
|
|
* Submits all the user added attributes to the GPU; once submitted, the
|
|
* attributes can be used for drawing.
|
|
*
|
|
* You should aim to minimize calls to this function since it implies
|
|
* validating your data; it potentially incurs a transport cost (especially if
|
|
* you are using GLX indirect rendering) and potentially a format conversion
|
|
* cost if the GPU doesn't natively support any of the given attribute formats.
|
|
*/
|
|
void
|
|
cogl_vertex_buffer_submit (CoglHandle handle);
|
|
|
|
/**
|
|
* cogl_vertex_buffer_disable:
|
|
* @handle: A vertex buffer handle
|
|
* @attribute_name: The name of the attribute you want to disable
|
|
*
|
|
* Disables a previosuly added attribute.
|
|
*
|
|
* Since it can be costly to add and remove new attributes to buffers; to make
|
|
* individual buffers more reuseable it is possible to enable and disable
|
|
* attributes before using a buffer for drawing.
|
|
*
|
|
* You don't need to call cogl_vertex_buffer_submit() after using this
|
|
* function.
|
|
*/
|
|
void
|
|
cogl_vertex_buffer_disable (CoglHandle handle,
|
|
const char *attribute_name);
|
|
|
|
/**
|
|
* cogl_vertex_buffer_enable:
|
|
* @handle: A vertex buffer handle
|
|
* @attribute_name: The name of the attribute you want to enable
|
|
*
|
|
* Enables a previosuly disabled attribute.
|
|
*
|
|
* Since it can be costly to add and remove new attributes to buffers; to make
|
|
* individual buffers more reuseable it is possible to enable and disable
|
|
* attributes before using a buffer for drawing.
|
|
*
|
|
* You don't need to call cogl_vertex_buffer_submit() after using this function
|
|
*/
|
|
void
|
|
cogl_vertex_buffer_enable (CoglHandle handle,
|
|
const char *attribute_name);
|
|
|
|
/**
|
|
* cogl_vertex_buffer_draw:
|
|
* @handle: A vertex buffer handle
|
|
* @mode: A #CoglVerticesMode specifying how the vertices should be
|
|
* interpreted.
|
|
* @first: Specifies the index of the first vertex you want to draw with
|
|
* @count: Specifies the number of vertices you want to draw.
|
|
*
|
|
* Allows you to draw geometry using all or a subset of the
|
|
* vertices in a vertex buffer.
|
|
*
|
|
* Any un-submitted attribute changes are automatically submitted before
|
|
* drawing.
|
|
*/
|
|
void
|
|
cogl_vertex_buffer_draw (CoglHandle handle,
|
|
CoglVerticesMode mode,
|
|
int first,
|
|
int count);
|
|
|
|
/**
|
|
* cogl_vertex_buffer_indices_new:
|
|
* @indices_type: a #CoglIndicesType specifying the data type used for
|
|
* the indices.
|
|
* @indices_array: (array length=indices_len): Specifies the address of
|
|
* your array of indices
|
|
* @indices_len: The number of indices in indices_array
|
|
*
|
|
* Depending on how much geometry you are submitting it can be worthwhile
|
|
* optimizing the number of redundant vertices you submit. Using an index
|
|
* array allows you to reference vertices multiple times, for example
|
|
* during triangle strips.
|
|
*
|
|
* Return value: A CoglHandle for the indices which you can pass to
|
|
* cogl_vertex_buffer_draw_elements().
|
|
*/
|
|
CoglHandle
|
|
cogl_vertex_buffer_indices_new (CoglIndicesType indices_type,
|
|
const void *indices_array,
|
|
int indices_len);
|
|
|
|
/**
|
|
* cogl_vertex_buffer_indices_get_type:
|
|
* @indices: An indices handle
|
|
*
|
|
* Queries back the data type used for the given indices
|
|
*
|
|
* Returns: The CoglIndicesType used
|
|
*/
|
|
CoglIndicesType
|
|
cogl_vertex_buffer_indices_get_type (CoglHandle indices);
|
|
|
|
/**
|
|
* cogl_vertex_buffer_draw_elements:
|
|
* @handle: A vertex buffer handle
|
|
* @mode: A #CoglVerticesMode specifying how the vertices should be
|
|
* interpreted.
|
|
* @indices: A CoglHandle for a set of indices allocated via
|
|
* cogl_vertex_buffer_indices_new ()
|
|
* @min_index: Specifies the minimum vertex index contained in indices
|
|
* @max_index: Specifies the maximum vertex index contained in indices
|
|
* @indices_offset: An offset into named indices. The offset marks the first
|
|
* index to use for drawing.
|
|
* @count: Specifies the number of vertices you want to draw.
|
|
*
|
|
* This function lets you use an array of indices to specify the vertices
|
|
* within your vertex buffer that you want to draw. The indices themselves
|
|
* are created by calling cogl_vertex_buffer_indices_new ()
|
|
*
|
|
* Any un-submitted attribute changes are automatically submitted before
|
|
* drawing.
|
|
*/
|
|
void
|
|
cogl_vertex_buffer_draw_elements (CoglHandle handle,
|
|
CoglVerticesMode mode,
|
|
CoglHandle indices,
|
|
int min_index,
|
|
int max_index,
|
|
int indices_offset,
|
|
int count);
|
|
|
|
#ifndef COGL_DISABLE_DEPRECATED
|
|
|
|
/**
|
|
* cogl_vertex_buffer_ref:
|
|
* @handle: a @CoglHandle.
|
|
*
|
|
* Increment the reference count for a vertex buffer
|
|
*
|
|
* Return value: the @handle.
|
|
*
|
|
* Deprecated: 1.2: Use cogl_handle_ref() instead
|
|
*/
|
|
CoglHandle
|
|
cogl_vertex_buffer_ref (CoglHandle handle) G_GNUC_DEPRECATED;
|
|
|
|
/**
|
|
* cogl_vertex_buffer_unref:
|
|
* @handle: a @CoglHandle.
|
|
*
|
|
* Decrement the reference count for a vertex buffer
|
|
*
|
|
* Deprecated: 1.2: Use cogl_handle_unref() instead
|
|
*/
|
|
void
|
|
cogl_vertex_buffer_unref (CoglHandle handle) G_GNUC_DEPRECATED;
|
|
|
|
#endif /* COGL_DISABLE_DEPRECATED */
|
|
|
|
/**
|
|
* cogl_vertex_buffer_indices_get_for_quads:
|
|
* @n_indices: the number of indices in the vertex buffer.
|
|
*
|
|
* Creates a vertex buffer containing the indices needed to draw pairs
|
|
* of triangles from a list of vertices grouped as quads. There will
|
|
* be at least @n_indices entries in the buffer (but there may be
|
|
* more).
|
|
*
|
|
* The indices will follow this pattern:
|
|
*
|
|
* 0, 1, 2, 0, 2, 3, 4, 5, 6, 4, 6, 7 ... etc
|
|
*
|
|
* For example, if you submit vertices for a quad like like that shown
|
|
* in <xref linkend="quad-indices-order"/> then you can request 6
|
|
* indices to render two triangles like those shown in <xref
|
|
* linkend="quad-indices-triangles"/>.
|
|
*
|
|
* <figure id="quad-indices-order">
|
|
* <title>Example of vertices submitted to form a quad</title>
|
|
* <graphic fileref="quad-indices-order.png" format="PNG"/>
|
|
* </figure>
|
|
*
|
|
* <figure id="quad-indices-triangles">
|
|
* <title>Illustration of the triangle indices that will be generated</title>
|
|
* <graphic fileref="quad-indices-triangles.png" format="PNG"/>
|
|
* </figure>
|
|
*
|
|
* Returns: A %CoglHandle containing the indices. The handled is
|
|
* owned by Cogl and should not be modified or unref'd.
|
|
*/
|
|
CoglHandle
|
|
cogl_vertex_buffer_indices_get_for_quads (unsigned int n_indices);
|
|
|
|
/**
|
|
* cogl_is_vertex_buffer:
|
|
* @handle: a #CoglHandle for a vertex buffer object
|
|
*
|
|
* Checks whether @handle is a Vertex Buffer Object
|
|
*
|
|
* Return value: %TRUE if the handle is a VBO, and %FALSE
|
|
* otherwise
|
|
*
|
|
* Since: 1.0
|
|
*/
|
|
gboolean
|
|
cogl_is_vertex_buffer (CoglHandle handle);
|
|
|
|
/**
|
|
* cogl_is_vertex_buffer_indices:
|
|
* @handle: a #CoglHandle
|
|
*
|
|
* Checks whether @handle is a handle to the indices for a vertex
|
|
* buffer object
|
|
*
|
|
* Return value: %TRUE if the handle is indices, and %FALSE
|
|
* otherwise
|
|
*
|
|
* Since: 1.4
|
|
*/
|
|
gboolean
|
|
cogl_is_vertex_buffer_indices (CoglHandle handle);
|
|
|
|
G_END_DECLS
|
|
|
|
#endif /* __COGL_VERTEX_BUFFER_H__ */
|