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. More...

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

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. More...

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

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

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

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. More...

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

Public Member Functions inherited from ZeroedMemoryAllocator
void *	operator new (size_t size)
	Memory allocator for a single class instance. More...

void *	operator new[] (size_t size)
	Memory allocator for an array of class instances. More...

void	operator delete (void *ptr)
	Memory release for a single class instance. More...

void	operator delete[] (void *ptr)
	Memory release for an array of class instances. More...

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. More...

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. More...

bool	InitShaders ()
	Create all needed shader programs. More...

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. More...

Private Attributes
bool	persistent_mapping_supported
	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
	Pointer to the mapped video buffer.

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

GLuint	vid_texture
	Texture handle for the video buffer texture.

GLuint	vid_program
	Shader program for rendering a RGBA video buffer.

GLuint	pal_program
	Shader program for rendering a paletted video buffer.

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

GLuint	vbo_quad
	Vertex buffer with a fullscreen quad.

GLuint	pal_texture
	Palette lookup texture.

void *	anim_buffer
	Pointer to the mapped animation buffer.

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

GLuint	anim_texture
	Texture handle for the animation buffer texture.

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

GLint	remap_sprite_loc
	Uniform location for sprite parameters.

GLint	remap_screen_loc
	Uniform location for screen size.

GLint	remap_zoom_loc
	Uniform location for sprite zoom.

GLint	remap_rgb_loc
	Uniform location for RGB mode flag.

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

GLint	sprite_sprite_loc
	Uniform location for sprite parameters.

GLint	sprite_screen_loc
	Uniform location for screen size.

GLint	sprite_zoom_loc
	Uniform location for sprite zoom.

GLint	sprite_rgb_loc
	Uniform location for RGB mode flag.

GLint	sprite_crash_loc
	Uniform location for crash remap mode flag.

LRUCache< SpriteID, Sprite >	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
	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.

Member Function Documentation

◆ 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.

◆ 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().

◆ 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 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, 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.

◆ 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().

◆ 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 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 1289 of file opengl.cpp.

◆ 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.

◆ 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().

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

Member Function Documentation

◆ Create()

◆ GetAnimBuffer()

◆ GetSpriteAlignment()

◆ GetVideoBuffer()

◆ Init()

◆ InitShaders()

◆ ReleaseAnimBuffer()

◆ ReleaseVideoBuffer()

◆ RenderOglSprite()

◆ Resize()

◆ UpdatePalette()