## GstGLFilter GstGLFilter — GstBaseTransform subclass for dealing with RGBA textures |

## Functions

gboolean | gst_gl_filter_render_to_target ()
void | gst_gl_filter_render_to_target_with_shader ()
gboolean | gst_gl_filter_filter_texture ()
void | gst_gl_filter_draw_fullscreen_quad ()

## Types and Values

| GstGLFilter
| GstGLFilterClass

## Object Hierarchy

        GObject
        ╰── GInitiallyUnowned
            ╰── GstObject
                ╰── GstElement
                    ╰── GstBaseTransform
                        ╰── GstGLBaseFilter
                            ╰── GstGLFilter

## Description

GstGLFilter helps to implement simple OpenGL filter elements taking a single input and producing a single output with a GstGLFramebuffer

## Functions

### gst_gl_filter_render_to_target ()

    gboolean
    gst_gl_filter_render_to_target (GstGLFilter *filter,
                                    GstGLMemory *input,
                                    GstGLMemory *output,
                                    GstGLFilterRenderFunc func,
                                    gpointer data);

Transforms `input` into `output` using `func` on through FBO.

#### Parameters

filter | a GstGLFilter |
input | the input texture |
output | the output texture |
func | the function to transform `input` into `output` . called with `data` . | [scope call]
data | the data associated with `func` . | [allow-none]

#### Returns

the return value of `func`

Since: 1.10

### gst_gl_filter_render_to_target_with_shader ()

    void
    gst_gl_filter_render_to_target_with_shader
                                   (GstGLFilter *filter,
                                    GstGLMemory *input,
                                    GstGLMemory *output,
                                    GstGLShader *shader);

Transforms `input` into `output` using `shader` with a FBO.

See also: `gst_gl_filter_render_to_target()`

#### Parameters

filter | a GstGLFilter |
input | the input texture |
output | the output texture |
shader | the shader to use. |

Since: 1.4

### gst_gl_filter_filter_texture ()

    gboolean
    gst_gl_filter_filter_texture (GstGLFilter *filter,
                                  GstBuffer *inbuf,
                                  GstBuffer *outbuf);

Perform automatic upload if needed, call filter_texture vfunc and then an automatic download if needed.

#### Parameters

filter | a GstGLFilter |
inbuf | an input buffer |
outbuf | an output buffer |

#### Returns

whether the transformation succeeded

Since: 1.4

### gst_gl_filter_draw_fullscreen_quad ()

    void
    gst_gl_filter_draw_fullscreen_quad (GstGLFilter *filter);

Render a fullscreen quad using the current GL state. The only GL state this modifies is the necessary vertex/index buffers and, if necessary, a Vertex Array Object for drawing a fullscreen quad. Framebuffer state, any shaders, viewport state, etc must be setup by the caller.

#### Parameters

filter | a GstGLFilter |

Since: 1.10

## Types and Values

### GstGLFilter

    typedef struct _GstGLFilter GstGLFilter;

#### Members

### GstGLFilterClass

    typedef struct {
      GstGLBaseFilterClass parent_class;

      gboolean (*set_caps)          (GstGLFilter* filter, GstCaps* incaps, GstCaps* outcaps);
      gboolean (*filter)            (GstGLFilter *filter, GstBuffer *inbuf, GstBuffer *outbuf);
      gboolean (*filter_texture)    (GstGLFilter *filter, GstGLMemory *in_tex, GstGLMemory *out_tex);
      gboolean (*init_fbo)          (GstGLFilter *filter);

      GstCaps *(*transform_internal_caps) (GstGLFilter *filter,
        GstPadDirection direction, GstCaps * caps, GstCaps * filter_caps);

      /* useful to init and cleanup custom gl resources */
      void (*display_init_cb)       (GstGLFilter *filter);
      void (*display_reset_cb)      (GstGLFilter *filter);
    } GstGLFilterClass;

#### Members

`set_caps` () | mirror from GstBaseTransform |
`filter` () | perform operations on the input and output buffers. In general, you should avoid using this method if at all possible. One valid use-case for using this is keeping previous buffers for future calculations. Note: If `filter` exists, then `filter_texture` is not run |
`filter_texture` () | given `in_tex` , transform it into `out_tex` . Not used if `filter` exists |
`init_fbo` () | perform initialization when the Framebuffer object is created |
`transform_internal_caps` () | Perform sub-class specific modifications of the caps to be processed between upload on input and before download for output. |
`display_init_cb` () | execute arbitrary gl code on start |
`display_reset_cb` () | execute arbitrary gl code at stop |

## See Also

GstBaseTransform, GstGLContext, GstGLFramebuffer