mir::compositor::GLRenderer Class Reference

#include <gl_renderer.h>

Inheritance diagram for mir::compositor::GLRenderer:

Classes
struct	Program

Public Member Functions
	GLRenderer (std::unique_ptr< graphics::GLTextureCache > &&texture_cache, geometry::Rectangle const &display_area, DestinationAlpha dest_alpha)
void	set_viewport (geometry::Rectangle const &rect) override
void	set_rotation (float degrees) override
void	render (graphics::RenderableList const &) const override
void	suspend () override
Public Member Functions inherited from mir::compositor::Renderer
virtual	~Renderer ()=default

Protected Member Functions
virtual void	tessellate (std::vector< graphics::GLPrimitive > &primitives, graphics::Renderable const &renderable) const
	tessellate defines the list of triangles that will be used to render the surface. More...
DestinationAlpha	destination_alpha () const
virtual void	draw (graphics::Renderable const &renderable, GLRenderer::Program const &prog) const
Protected Member Functions inherited from mir::compositor::Renderer
	Renderer ()=default
	Renderer (const Renderer &)=delete
Renderer &	operator= (const Renderer &)=delete

Protected Attributes
GLfloat	clear_color [4]
long long	frameno = 0
GLProgramFamily	family
Program	default_program
Program	alpha_program

Static Protected Attributes
static const GLchar *const	vshader
static const GLchar *const	default_fshader
static const GLchar *const	alpha_fshader

Constructor & Destructor Documentation

mir::compositor::GLRenderer::GLRenderer	(	std::unique_ptr< graphics::GLTextureCache > &&	texture_cache,
		geometry::Rectangle const &	display_area,
		DestinationAlpha	dest_alpha
	)

Member Function Documentation

mc::DestinationAlpha mir::compositor::GLRenderer::destination_alpha ( ) const

protected

void mir::compositor::GLRenderer::draw ( graphics::Renderable const &  renderable, GLRenderer::Program const &  prog  ) const

protectedvirtual

void mir::compositor::GLRenderer::render ( graphics::RenderableList const &  renderables ) const

overridevirtual

Implements mir::compositor::Renderer.

void mir::compositor::GLRenderer::set_rotation ( float  degrees )

overridevirtual

Implements mir::compositor::Renderer.

void mir::compositor::GLRenderer::set_viewport ( geometry::Rectangle const &  rect )

overridevirtual

Implements mir::compositor::Renderer.

void mir::compositor::GLRenderer::suspend ( )

overridevirtual

Implements mir::compositor::Renderer.

void mir::compositor::GLRenderer::tessellate ( std::vector< graphics::GLPrimitive > &  primitives, graphics::Renderable const &  renderable  ) const

protectedvirtual

tessellate defines the list of triangles that will be used to render the surface.

By default it just returns 4 vertices for a rectangle. However you can override its behaviour to tessellate more finely and deform freely for effects like wobbly windows.

Parameters

[in,out]	primitives	The list of rendering primitives to be grown and/or modified.
[in]	renderable	The renderable surface being tessellated.

Note

The cohesion of this function to GLRenderer is quite loose and it does not strictly need to reside here. However it seems a good choice under GLRenderer while this remains the only OpenGL-specific class in the display server, and tessellation is very much OpenGL-specific.

Member Data Documentation

const GLchar *const mir::compositor::GLRenderer::alpha_fshader

staticprotected

Initial value:

=
{
    "precision mediump float;\n"
    "uniform sampler2D tex;\n"
    "uniform float alpha;\n"
    "varying vec2 v_texcoord;\n"
    "void main() {\n"
    "   vec4 frag = texture2D(tex, v_texcoord);\n"
    "   gl_FragColor = alpha*frag;\n"
    "}\n"
}

Program mir::compositor::GLRenderer::alpha_program

protected

GLfloat mir::compositor::GLRenderer::clear_color[4]

protected

const GLchar *const mir::compositor::GLRenderer::default_fshader

staticprotected

Initial value:

=
{   
    "precision mediump float;\n"
    "uniform sampler2D tex;\n"
    "varying vec2 v_texcoord;\n"
    "void main() {\n"
    "   gl_FragColor = texture2D(tex, v_texcoord);\n"
    "}\n"
}

Program mir::compositor::GLRenderer::default_program

protected

GLProgramFamily mir::compositor::GLRenderer::family

protected

long long mir::compositor::GLRenderer::frameno = 0

mutableprotected

const GLchar *const mir::compositor::GLRenderer::vshader

staticprotected

Initial value:

=
{
    "attribute vec3 position;\n"
    "attribute vec2 texcoord;\n"
    "uniform mat4 screen_to_gl_coords;\n"
    "uniform mat4 display_transform;\n"
    "uniform mat4 transform;\n"
    "uniform vec2 centre;\n"
    "varying vec2 v_texcoord;\n"
    "void main() {\n"
    "   vec4 mid = vec4(centre, 0.0, 0.0);\n"
    "   vec4 transformed = (transform * (vec4(position, 1.0) - mid)) + mid;\n"
    "   gl_Position = display_transform * screen_to_gl_coords * transformed;\n"
    "   v_texcoord = texcoord;\n"
    "}\n"
}

---

The documentation for this class was generated from the following files:

• src/include/server/mir/compositor/gl_renderer.h
• src/server/compositor/gl_renderer.cpp