Platform-independent back-end class for OpenGL video drivers. More...

#include <opengl.h>

Inheritance diagram for OpenGLBackend:

Public Member Functions
void	PrepareContext ()

std::string	GetDriverName ()

void	UpdatePalette (const Colour *pal, uint first, uint length)
	Update the stored palette.

bool	Resize (int w, int h, bool force=false)
	Change the size of the drawing window and allocate matching resources.

void	Paint ()
	Render video buffer to the screen.

void	DrawMouseCursor ()
	Draw mouse cursor on screen.

void	PopulateCursorCache ()

void	ClearCursorCache ()
	Queue a request for cursor cache clear.

void *	GetVideoBuffer ()
	Get a pointer to the memory for the video driver to draw to.

uint8_t *	GetAnimBuffer ()
	Get a pointer to the memory for the separate animation buffer.

void	ReleaseVideoBuffer (const Rect &update_rect)
	Update video buffer texture after the video buffer was filled.

void	ReleaseAnimBuffer (const Rect &update_rect)
	Update animation buffer texture after the animation buffer was filled.

bool	Is32BppSupported () override
	Can the sprite encoder make use of RGBA sprites?

uint	GetSpriteAlignment () override
	Get the value which the height and width on a sprite have to be aligned by.

Sprite *	Encode (const SpriteLoader::SpriteCollection &sprite, SpriteAllocator &allocator) override
	Convert a sprite from the loader to our own format.

Static Public Member Functions
static OpenGLBackend *	Get ()
	Get singleton instance of this class.

static std::optional< std::string_view >	Create (GetOGLProcAddressProc get_proc, const Dimension &screen_res)
	Create and initialize the singleton back-end class.

static void	Destroy ()
	Free resources and destroy singleton back-end class.

Private Member Functions
	OpenGLBackend ()
	Construct OpenGL back-end class.

	~OpenGLBackend ()
	Free allocated resources.

std::optional< std::string_view >	Init (const Dimension &screen_res)
	Check for the needed OpenGL functionality and allocate all resources.

bool	InitShaders ()
	Create all needed shader programs.

void	InternalClearCursorCache ()
	Clear all cached cursor sprites.

void	RenderOglSprite (OpenGLSprite *gl_sprite, PaletteID pal, int x, int y, ZoomLevel zoom)
	Render a sprite to the back buffer.

Private Attributes
bool	persistent_mapping_supported = false
	Persistent pixel buffer mapping supported.

GLsync	sync_vid_mapping {}
	Sync object for the persistently mapped video buffer.

GLsync	sync_anim_mapping {}
	Sync object for the persistently mapped animation buffer.

void *	vid_buffer = nullptr
	Pointer to the mapped video buffer.

GLuint	vid_pbo = 0
	Pixel buffer object storing the memory used for the video driver to draw to.

GLuint	vid_texture = 0
	Texture handle for the video buffer texture.

GLuint	vid_program = 0
	Shader program for rendering a RGBA video buffer.

GLuint	pal_program = 0
	Shader program for rendering a paletted video buffer.

GLuint	vao_quad = 0
	Vertex array object storing the rendering state for the fullscreen quad.

GLuint	vbo_quad = 0
	Vertex buffer with a fullscreen quad.

GLuint	pal_texture = 0
	Palette lookup texture.

void *	anim_buffer = nullptr
	Pointer to the mapped animation buffer.

GLuint	anim_pbo = 0
	Pixel buffer object storing the memory used for the animation buffer.

GLuint	anim_texture = 0
	Texture handle for the animation buffer texture.

GLuint	remap_program = 0
	Shader program for blending and rendering a RGBA + remap texture.

GLint	remap_sprite_loc = 0
	Uniform location for sprite parameters.

GLint	remap_screen_loc = 0
	Uniform location for screen size.

GLint	remap_zoom_loc = 0
	Uniform location for sprite zoom.

GLint	remap_rgb_loc = 0
	Uniform location for RGB mode flag.

GLuint	sprite_program = 0
	Shader program for blending and rendering a sprite to the video buffer.

GLint	sprite_sprite_loc = 0
	Uniform location for sprite parameters.

GLint	sprite_screen_loc = 0
	Uniform location for screen size.

GLint	sprite_zoom_loc = 0
	Uniform location for sprite zoom.

GLint	sprite_rgb_loc = 0
	Uniform location for RGB mode flag.

GLint	sprite_crash_loc = 0
	Uniform location for crash remap mode flag.

LRUCache< SpriteID, OpenGLSprite >	cursor_cache
	Cache of encoded cursor sprites.

PaletteID	last_sprite_pal = (PaletteID)-1
	Last uploaded remap palette.

bool	clear_cursor_cache = false
	A clear of the cursor cache is pending.

Point	cursor_pos {}
	Cursor position.

bool	cursor_in_window = false
	Cursor inside this window.

std::vector< CursorSprite >	cursor_sprites {}
	Sprites comprising cursor.

Static Private Attributes
static OpenGLBackend *	instance = nullptr
	Singleton instance pointer.

Detailed Description

Platform-independent back-end class for OpenGL video drivers.

Definition at line 28 of file opengl.h.

Constructor & Destructor Documentation

◆ OpenGLBackend()

OpenGLBackend::OpenGLBackend ( )

private

Construct OpenGL back-end class.

Definition at line 489 of file opengl.cpp.

Referenced by Create().

◆ ~OpenGLBackend()

OpenGLBackend::~OpenGLBackend ( )

private

Free allocated resources.

Definition at line 496 of file opengl.cpp.

References anim_pbo, anim_texture, OpenGLSprite::Destroy(), InternalClearCursorCache(), pal_program, pal_texture, remap_program, sprite_program, vao_quad, vbo_quad, vid_pbo, vid_program, and vid_texture.

Member Function Documentation

◆ ClearCursorCache()

void OpenGLBackend::ClearCursorCache ( )

Queue a request for cursor cache clear.

Definition at line 1135 of file opengl.cpp.

References clear_cursor_cache.

Referenced by VideoDriver_SDL_OpenGL::ClearSystemSprites().

◆ Create()

std::optional< std::string_view > OpenGLBackend::Create	(	GetOGLProcAddressProc	get_proc,
		const Dimension &	screen_res
	)

static

Create and initialize the singleton back-end class.

Parameters

get_proc	Callback to get an OpenGL function from the OS driver.
screen_res	Current display resolution.

Returns: std::nullopt on success, error message otherwise.

Definition at line 467 of file opengl.cpp.

References Destroy(), Init(), instance, and OpenGLBackend().

◆ Destroy()

void OpenGLBackend::Destroy ( )

static

Free resources and destroy singleton back-end class.

Definition at line 480 of file opengl.cpp.

References instance.

Referenced by Create().

◆ DrawMouseCursor()

void OpenGLBackend::DrawMouseCursor ( )

Draw mouse cursor on screen.

Definition at line 1071 of file opengl.cpp.

References LRUCache< Tkey, Tdata >::Contains(), cursor_cache, cursor_in_window, cursor_sprites, LRUCache< Tkey, Tdata >::Get(), RenderOglSprite(), UnScaleByZoom(), OpenGLSprite::x_offs, and OpenGLSprite::y_offs.

Referenced by VideoDriver_SDL_OpenGL::Paint().

◆ Encode()

Sprite * OpenGLBackend::Encode	(	const SpriteLoader::SpriteCollection &	sprite,
		SpriteAllocator &	allocator
	)

overridevirtual

Convert a sprite from the loader to our own format.

Implements SpriteEncoder.

Definition at line 1261 of file opengl.cpp.

References LRUCache< Tkey, Tdata >::Insert().

◆ Get()

static OpenGLBackend * OpenGLBackend::Get ( )

inlinestatic

Get singleton instance of this class.

Definition at line 82 of file opengl.h.

References instance.

Referenced by VideoDriver_SDL_OpenGL::AllocateBackingStore(), VideoDriver_SDL_OpenGL::ClearSystemSprites(), VideoDriver_SDL_OpenGL::GetVideoPointer(), VideoDriver_SDL_OpenGL::Paint(), VideoDriver_SDL_OpenGL::PopulateSystemSprites(), VideoDriver_SDL_OpenGL::ReleaseVideoPointer(), and VideoDriver_SDL_OpenGL::Start().

◆ GetAnimBuffer()

uint8_t * OpenGLBackend::GetAnimBuffer ( )

Get a pointer to the memory for the separate animation buffer.

Returns: Pointer to draw on.

Definition at line 1170 of file opengl.cpp.

References anim_buffer, anim_pbo, persistent_mapping_supported, and sync_anim_mapping.

Referenced by VideoDriver_SDL_OpenGL::GetVideoPointer().

◆ GetDriverName()

std::string OpenGLBackend::GetDriverName ( )

Definition at line 744 of file opengl.cpp.

◆ GetSpriteAlignment()

uint OpenGLBackend::GetSpriteAlignment ( )

inlineoverridevirtual

Get the value which the height and width on a sprite have to be aligned by.

Returns: The needed alignment or 0 if any alignment is accepted.

Reimplemented from SpriteEncoder.

Definition at line 109 of file opengl.h.

References ZOOM_LVL_END.

◆ GetVideoBuffer()

void * OpenGLBackend::GetVideoBuffer ( )

Get a pointer to the memory for the video driver to draw to.

Returns: Pointer to draw on.

Definition at line 1148 of file opengl.cpp.

References BlitterFactory::GetCurrentBlitter(), Blitter::GetScreenDepth(), persistent_mapping_supported, sync_vid_mapping, vid_buffer, and vid_pbo.

Referenced by VideoDriver_SDL_OpenGL::GetVideoPointer().

◆ Init()

std::optional< std::string_view > OpenGLBackend::Init ( const Dimension & screen_res )

private

Check for the needed OpenGL functionality and allocate all resources.

Parameters

screen_res Current display resolution.

Returns: Error string or std::nullopt if successful.

Definition at line 525 of file opengl.cpp.

References anim_pbo, anim_texture, OpenGLSprite::Create(), Debug, InitShaders(), IsOpenGLVersionAtLeast(), pal_program, pal_texture, persistent_mapping_supported, remap_program, remap_rgb_loc, remap_screen_loc, remap_sprite_loc, remap_zoom_loc, sprite_crash_loc, sprite_program, sprite_rgb_loc, sprite_screen_loc, sprite_sprite_loc, sprite_zoom_loc, vao_quad, vbo_quad, vid_pbo, vid_program, and vid_texture.

Referenced by Create().

◆ InitShaders()

bool OpenGLBackend::InitShaders ( )

private

Create all needed shader programs.

Returns: True if successful, false otherwise.

Definition at line 804 of file opengl.cpp.

References _frag_shader_direct, _frag_shader_direct_150, _frag_shader_palette, _frag_shader_palette_150, _frag_shader_rgb_mask_blend, _frag_shader_rgb_mask_blend_150, _frag_shader_sprite_blend, _frag_shader_sprite_blend_150, _vertex_shader_sprite, _vertex_shader_sprite_150, IsOpenGLVersionAtLeast(), lengthof, pal_program, remap_program, sprite_program, and vid_program.

Referenced by Init().

◆ InternalClearCursorCache()

void OpenGLBackend::InternalClearCursorCache ( )

private

Clear all cached cursor sprites.

Definition at line 1127 of file opengl.cpp.

References LRUCache< Tkey, Tdata >::Clear(), and cursor_cache.

Referenced by ~OpenGLBackend().

◆ Is32BppSupported()

bool OpenGLBackend::Is32BppSupported ( )

inlineoverridevirtual

Can the sprite encoder make use of RGBA sprites?

Implements SpriteEncoder.

Definition at line 108 of file opengl.h.

◆ Paint()

void OpenGLBackend::Paint ( )

Render video buffer to the screen.

Definition at line 1039 of file opengl.cpp.

References anim_texture, BlitterFactory::GetCurrentBlitter(), pal_program, pal_texture, remap_program, remap_rgb_loc, remap_screen_loc, remap_sprite_loc, remap_zoom_loc, vao_quad, vid_program, and vid_texture.

Referenced by VideoDriver_SDL_OpenGL::Paint().

◆ PopulateCursorCache()

void OpenGLBackend::PopulateCursorCache ( )

Definition at line 1100 of file opengl.cpp.

◆ PrepareContext()

void OpenGLBackend::PrepareContext ( )

Definition at line 735 of file opengl.cpp.

◆ ReleaseAnimBuffer()

void OpenGLBackend::ReleaseAnimBuffer ( const Rect & update_rect )

Update animation buffer texture after the animation buffer was filled.

Parameters

update_rect Rectangle encompassing the dirty region of the animation buffer.

Definition at line 1231 of file opengl.cpp.

References anim_buffer, anim_pbo, anim_texture, persistent_mapping_supported, and sync_anim_mapping.

Referenced by VideoDriver_SDL_OpenGL::ReleaseVideoPointer().

◆ ReleaseVideoBuffer()

void OpenGLBackend::ReleaseVideoBuffer ( const Rect & update_rect )

Update video buffer texture after the video buffer was filled.

Parameters

update_rect Rectangle encompassing the dirty region of the video buffer.

Definition at line 1193 of file opengl.cpp.

References BlitterFactory::GetCurrentBlitter(), IsEmptyRect(), persistent_mapping_supported, sync_vid_mapping, vid_buffer, vid_pbo, and vid_texture.

Referenced by VideoDriver_SDL_OpenGL::ReleaseVideoPointer().

◆ RenderOglSprite()

void OpenGLBackend::RenderOglSprite	(	OpenGLSprite *	gl_sprite,
		PaletteID	pal,
		int	x,
		int	y,
		ZoomLevel	zoom
	)

private

Render a sprite to the back buffer.

Parameters

gl_sprite	Sprite to render.
x	X position of the sprite.
y	Y position of the sprite.
zoom	Zoom level to use.

Definition at line 1277 of file opengl.cpp.

References OpenGLSprite::BindTextures(), GB(), OpenGLSprite::GetSize(), last_sprite_pal, OpenGLSprite::pal_identity, OpenGLSprite::pal_pbo, OpenGLSprite::pal_tex, pal_texture, PALETTE_CRASH, PALETTE_WIDTH, Recolour, sprite_crash_loc, sprite_program, sprite_rgb_loc, sprite_screen_loc, sprite_sprite_loc, sprite_zoom_loc, and vao_quad.

Referenced by DrawMouseCursor().

◆ Resize()

bool OpenGLBackend::Resize	(	int	w,
		int	h,
		bool	force = `false`
	)

Change the size of the drawing window and allocate matching resources.

Parameters

w	New width of the window.
h	New height of the window.
force	Recreate resources even if size didn't change.
False	if nothing had to be done, true otherwise.

Definition at line 913 of file opengl.cpp.

References Align(), anim_buffer, anim_pbo, anim_texture, BlitterFactory::GetCurrentBlitter(), Blitter::GetScreenDepth(), persistent_mapping_supported, remap_program, remap_screen_loc, vid_buffer, vid_pbo, and vid_texture.

Referenced by VideoDriver_SDL_OpenGL::AllocateBackingStore().

◆ UpdatePalette()

void OpenGLBackend::UpdatePalette	(	const Colour *	pal,
		uint	first,
		uint	length
	)

Update the stored palette.

Parameters

pal	Palette array with at least 256 elements.
first	First entry to update.
length	Number of entries to update.

Definition at line 1025 of file opengl.cpp.

References pal_texture.

Referenced by VideoDriver_SDL_OpenGL::Paint().

Field Documentation

◆ anim_buffer

void* OpenGLBackend::anim_buffer = nullptr

private

Pointer to the mapped animation buffer.

Definition at line 45 of file opengl.h.

Referenced by GetAnimBuffer(), ReleaseAnimBuffer(), and Resize().

◆ anim_pbo

GLuint OpenGLBackend::anim_pbo = 0

private

Pixel buffer object storing the memory used for the animation buffer.

Definition at line 46 of file opengl.h.

Referenced by GetAnimBuffer(), Init(), ReleaseAnimBuffer(), Resize(), and ~OpenGLBackend().

◆ anim_texture

GLuint OpenGLBackend::anim_texture = 0

private

Texture handle for the animation buffer texture.

Definition at line 47 of file opengl.h.

Referenced by Init(), Paint(), ReleaseAnimBuffer(), Resize(), and ~OpenGLBackend().

◆ clear_cursor_cache

bool OpenGLBackend::clear_cursor_cache = false

private

A clear of the cursor cache is pending.

Definition at line 64 of file opengl.h.

Referenced by ClearCursorCache().

◆ cursor_cache

LRUCache<SpriteID, OpenGLSprite> OpenGLBackend::cursor_cache

private

Cache of encoded cursor sprites.

Definition at line 62 of file opengl.h.

Referenced by DrawMouseCursor(), and InternalClearCursorCache().

◆ cursor_in_window

bool OpenGLBackend::cursor_in_window = false

private

Cursor inside this window.

Definition at line 67 of file opengl.h.

Referenced by DrawMouseCursor().

◆ cursor_pos

Point OpenGLBackend::cursor_pos {}

private

Cursor position.

Definition at line 66 of file opengl.h.

◆ cursor_sprites

std::vector<CursorSprite> OpenGLBackend::cursor_sprites {}

private

Sprites comprising cursor.

Definition at line 68 of file opengl.h.

Referenced by DrawMouseCursor().

◆ instance

OpenGLBackend * OpenGLBackend::instance = nullptr

staticprivate

Singleton instance pointer.

Definition at line 30 of file opengl.h.

Referenced by Create(), Destroy(), and Get().

◆ last_sprite_pal

PaletteID OpenGLBackend::last_sprite_pal = (PaletteID)-1

private

Last uploaded remap palette.

Definition at line 63 of file opengl.h.

Referenced by RenderOglSprite().

◆ pal_program

GLuint OpenGLBackend::pal_program = 0

private

Shader program for rendering a paletted video buffer.

Definition at line 40 of file opengl.h.

Referenced by Init(), InitShaders(), Paint(), and ~OpenGLBackend().

◆ pal_texture

GLuint OpenGLBackend::pal_texture = 0

private

Palette lookup texture.

Definition at line 43 of file opengl.h.

Referenced by Init(), Paint(), RenderOglSprite(), UpdatePalette(), and ~OpenGLBackend().

◆ persistent_mapping_supported

bool OpenGLBackend::persistent_mapping_supported = false

private

Persistent pixel buffer mapping supported.

Definition at line 32 of file opengl.h.

Referenced by GetAnimBuffer(), GetVideoBuffer(), Init(), ReleaseAnimBuffer(), ReleaseVideoBuffer(), and Resize().

◆ remap_program

GLuint OpenGLBackend::remap_program = 0

private

Shader program for blending and rendering a RGBA + remap texture.

Definition at line 49 of file opengl.h.

Referenced by Init(), InitShaders(), Paint(), Resize(), and ~OpenGLBackend().

◆ remap_rgb_loc

GLint OpenGLBackend::remap_rgb_loc = 0

private

Uniform location for RGB mode flag.

Definition at line 53 of file opengl.h.

Referenced by Init(), and Paint().

◆ remap_screen_loc

GLint OpenGLBackend::remap_screen_loc = 0

private

Uniform location for screen size.

Definition at line 51 of file opengl.h.

Referenced by Init(), Paint(), and Resize().

◆ remap_sprite_loc

GLint OpenGLBackend::remap_sprite_loc = 0

private

Uniform location for sprite parameters.

Definition at line 50 of file opengl.h.

Referenced by Init(), and Paint().

◆ remap_zoom_loc

GLint OpenGLBackend::remap_zoom_loc = 0

private

Uniform location for sprite zoom.

Definition at line 52 of file opengl.h.

Referenced by Init(), and Paint().

◆ sprite_crash_loc

GLint OpenGLBackend::sprite_crash_loc = 0

private

Uniform location for crash remap mode flag.

Definition at line 60 of file opengl.h.

Referenced by Init(), and RenderOglSprite().

◆ sprite_program

GLuint OpenGLBackend::sprite_program = 0

private

Shader program for blending and rendering a sprite to the video buffer.

Definition at line 55 of file opengl.h.

Referenced by Init(), InitShaders(), RenderOglSprite(), and ~OpenGLBackend().

◆ sprite_rgb_loc

GLint OpenGLBackend::sprite_rgb_loc = 0

private

Uniform location for RGB mode flag.

Definition at line 59 of file opengl.h.

Referenced by Init(), and RenderOglSprite().

◆ sprite_screen_loc

GLint OpenGLBackend::sprite_screen_loc = 0

private

Uniform location for screen size.

Definition at line 57 of file opengl.h.

Referenced by Init(), and RenderOglSprite().

◆ sprite_sprite_loc

GLint OpenGLBackend::sprite_sprite_loc = 0

private

Uniform location for sprite parameters.

Definition at line 56 of file opengl.h.

Referenced by Init(), and RenderOglSprite().

◆ sprite_zoom_loc

GLint OpenGLBackend::sprite_zoom_loc = 0

private

Uniform location for sprite zoom.

Definition at line 58 of file opengl.h.

Referenced by Init(), and RenderOglSprite().

◆ sync_anim_mapping

GLsync OpenGLBackend::sync_anim_mapping {}

private

Sync object for the persistently mapped animation buffer.

Definition at line 34 of file opengl.h.

Referenced by GetAnimBuffer(), and ReleaseAnimBuffer().

◆ sync_vid_mapping

GLsync OpenGLBackend::sync_vid_mapping {}

private

Sync object for the persistently mapped video buffer.

Definition at line 33 of file opengl.h.

Referenced by GetVideoBuffer(), and ReleaseVideoBuffer().

◆ vao_quad

GLuint OpenGLBackend::vao_quad = 0

private

Vertex array object storing the rendering state for the fullscreen quad.

Definition at line 41 of file opengl.h.

Referenced by Init(), Paint(), RenderOglSprite(), and ~OpenGLBackend().

◆ vbo_quad

GLuint OpenGLBackend::vbo_quad = 0

private

Vertex buffer with a fullscreen quad.

Definition at line 42 of file opengl.h.

Referenced by Init(), and ~OpenGLBackend().

◆ vid_buffer

void* OpenGLBackend::vid_buffer = nullptr

private

Pointer to the mapped video buffer.

Definition at line 36 of file opengl.h.

Referenced by GetVideoBuffer(), ReleaseVideoBuffer(), and Resize().

◆ vid_pbo

GLuint OpenGLBackend::vid_pbo = 0

private

Pixel buffer object storing the memory used for the video driver to draw to.

Definition at line 37 of file opengl.h.

Referenced by GetVideoBuffer(), Init(), ReleaseVideoBuffer(), Resize(), and ~OpenGLBackend().

◆ vid_program

GLuint OpenGLBackend::vid_program = 0

private

Shader program for rendering a RGBA video buffer.

Definition at line 39 of file opengl.h.

Referenced by Init(), InitShaders(), Paint(), and ~OpenGLBackend().

◆ vid_texture

GLuint OpenGLBackend::vid_texture = 0

private

Texture handle for the video buffer texture.

Definition at line 38 of file opengl.h.

Referenced by Init(), Paint(), ReleaseVideoBuffer(), Resize(), and ~OpenGLBackend().

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

src/video/opengl.h
src/video/opengl.cpp

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ OpenGLBackend()

◆ ~OpenGLBackend()

Member Function Documentation

◆ ClearCursorCache()

◆ Create()

◆ Destroy()

◆ DrawMouseCursor()

◆ Encode()

◆ Get()

◆ GetAnimBuffer()

◆ GetDriverName()

◆ GetSpriteAlignment()

◆ GetVideoBuffer()

◆ Init()

◆ InitShaders()

◆ InternalClearCursorCache()

◆ Is32BppSupported()

◆ Paint()

◆ PopulateCursorCache()

◆ PrepareContext()

◆ ReleaseAnimBuffer()

◆ ReleaseVideoBuffer()

◆ RenderOglSprite()

◆ Resize()

◆ UpdatePalette()

Field Documentation

◆ anim_buffer

◆ anim_pbo

◆ anim_texture

◆ clear_cursor_cache

◆ cursor_cache

◆ cursor_in_window

◆ cursor_pos

◆ cursor_sprites

◆ instance

◆ last_sprite_pal

◆ pal_program

◆ pal_texture

◆ persistent_mapping_supported

◆ remap_program

◆ remap_rgb_loc

◆ remap_screen_loc

◆ remap_sprite_loc

◆ remap_zoom_loc

◆ sprite_crash_loc

◆ sprite_program

◆ sprite_rgb_loc

◆ sprite_screen_loc

◆ sprite_sprite_loc

◆ sprite_zoom_loc

◆ sync_anim_mapping

◆ sync_vid_mapping

◆ vao_quad

◆ vbo_quad

◆ vid_buffer

◆ vid_pbo

◆ vid_program

◆ vid_texture