NAME

SDL2::render - SDL 2D Rendering Functions

SYNOPSIS

    use SDL2 qw[:render];

DESCRIPTION

Header file for SDL 2D rendering functions.

This API supports the following features:

single pixel points
single pixel lines
filled rectangles
texture images

The primitives may be drawn in opaque, blended, or additive modes.

The texture images may be drawn in opaque, blended, or additive modes. They can have an additional color tint or alpha modulation applied to them, and may also be stretched with linear interpolation.

This API is designed to accelerate simple 2D operations. You may want more functionality such as polygons and particle effects and in that case you should use SDL's OpenGL/Direct3D support or one of the many good 3D engines.

These functions must be called from the main thread. See this bug for details: http://bugzilla.libsdl.org/show_bug.cgi?id=1995

Functions

These functions may be imported by name or with the :render tag.

`SDL_GetNumRenderDrivers( )`

Get the number of 2D rendering drivers available for the current display.

        my $drivers = SDL_GetNumRenderDrivers( );

A render driver is a set of code that handles rendering and texture management on a particular display. Normally there is only one, but some drivers may have several available with different capabilities.

There may be none if SDL was compiled without render support.

Returns a number >= 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_GetRenderDriverInfo( ... )`

Get info about a specific 2D rendering driver for the current display.

        my $info = !SDL_GetRendererDriverInfo( );

Expected parameters include:

index - the index of the driver to query information about

Returns an SDL2::RendererInfo structure on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_CreateWindowAndRenderer( ... )`

Create a window and default renderer.

        my ($window, $renderer) = SDL_CreateWindowAndRenderer(640, 480, 0);

Expected parameters include:

width - the width of the window
height - the height of the window
window_flags - the flags used to create the window (see SDL_CreateWindow( ... ))

Returns a SDL2::Window and SDL2::Renderer objects on success, or -1 on error; call SDL_GetError( ) for more information.

`SDL_CreateRenderer( ... )`

Create a 2D rendering context for a window.

        my $renderer = SDL_CreateRenderer( $window, -1, 0);

Expected parameters include:

window - the window where rendering is displayed
index - the index of the rendering driver to initialize, or -1 to initialize the first one supporting the requested flags
flags - 0, or one or more SDL_RendererFlags OR'd together

Returns a valid rendering context or undefined if there was an error; call SDL_GetError( ) for more information.

`SDL_CreateSoftwareRenderer( ... )`

Create a 2D software rendering context for a surface.

        my $renderer = SDL_CreateSoftwareRenderer( $surface );

Two other API which can be used to create SDL_Renderer:

SDL_CreateRenderer( ... ) and SDL_CreateWindowAndRenderer( ... ). These can also create a software renderer, but they are intended to be used with an SDL2::Window as the final destination and not an SDL2::Surface.

Expected parameters include:

surface - the SDL2::Surface structure representing the surface where rendering is done

Returns a valid rendering context or undef if there was an error; call SDL_GetError( ) for more information.

`SDL_GetRenderer( ... )`

Get the renderer associated with a window.

        my $renderer = SDL_GetRenderer( $window );

Expected parameters include:

window - the window to query

Returns the rendering context on success or undef on failure; call SDL_GetError( ) for more information.

`SDL_GetRendererInfo( ... )`

Get information about a rendering context.

        my $info = !SDL_GetRendererInfo( $renderer );

Expected parameters include:

renderer - the rendering context

Returns an SDL2::RendererInfo structure on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_GetRendererOutputSize( ... )`

Get the output size in pixels of a rendering context.

        my ($w, $h) = SDL_GetRendererOutputSize( $renderer );

Due to high-dpi displays, you might end up with a rendering context that has more pixels than the window that contains it, so use this instead of SDL_GetWindowSize( ... ) to decide how much drawing area you have.

Expected parameters include:

renderer - the rendering context

Returns the width and height on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_CreateTexture( ... )`

Create a texture for a rendering context.

    my $texture = SDL_CreateTexture( $renderer, SDL_PIXELFORMAT_RGBA8888, SDL_TEXTUREACCESS_TARGET, 1024, 768);

You can set the texture scaling method by setting SDL_HINT_RENDER_SCALE_QUALITY before creating the texture.

Expected parameters include:

renderer - the rendering context
format - one of the enumerated values in :pixelFormatEnum
access - one of the enumerated values in :textureAccess
w - the width of the texture in pixels
h - the height of the texture in pixels

Returns a pointer to the created texture or undefined if no rendering context was active, the format was unsupported, or the width or height were out of range; call SDL_GetError( ) for more information.

`SDL_CreateTextureFromSurface( ... )`

Create a texture from an existing surface.

        use Config;
        my ($rmask, $gmask, $bmask, $amask) =
        $Config{byteorder} == 4321 ? (0xff000000,0x00ff0000,0x0000ff00,0x000000ff) :
                                                         (0x000000ff,0x0000ff00,0x00ff0000,0xff000000);
        my $surface = SDL_CreateRGBSurface( 0, 640, 480, 32, $rmask, $gmask, $bmask, $amask );
        my $texture = SDL_CreateTextureFromSurface( $renderer, $surface );

The surface is not modified or freed by this function.

The SDL_TextureAccess hint for the created texture is SDL_TEXTUREACCESS_STATIC.

The pixel format of the created texture may be different from the pixel format of the surface. Use SDL_QueryTexture( ... ) to query the pixel format of the texture.

Expected parameters include:

renderer - the rendering context
surface - the SDL2::Surface structure containing pixel data used to fill the texture

Returns the created texture or undef on failure; call SDL_GetError( ) for more information.

`SDL_QueryTexture( ... )`

Query the attributes of a texture.

        my ( $format, $access, $w, $h ) = SDL_QueryTexture( $texture );

Expected parameters include:

texture - the texture to query

Returns the following on success...

format - a pointer filled in with the raw format of the texture; the actual format may differ, but pixel transfers will use this format (one of the SDL_PixelFormatEnum values)
access - a pointer filled in with the actual access to the texture (one of the SDL_TextureAccess values)
w - a pointer filled in with the width of the texture in pixels
h - a pointer filled in with the height of the texture in pixels

...or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_SetTextureColorMod( ... )`

Set an additional color value multiplied into render copy operations.

        my $ok = !SDL_SetTextureColorMod( $texture, 64, 64, 64 );

When this texture is rendered, during the copy operation each source color channel is modulated by the appropriate color value according to the following formula:

        srcC = srcC * (color / 255)

Color modulation is not always supported by the renderer; it will return -1 if color modulation is not supported.

Expected parameters include:

texture - the texture to update
r - the red color value multiplied into copy operations
g - the green color value multiplied into copy operations
b - the blue color value multiplied into copy operations

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_GetTextureColorMod( ... )`

Get the additional color value multiplied into render copy operations.

        my ( $r, $g, $b ) = SDL_GetTextureColorMod( $texture );

Expected parameters include:

texture - the texture to query

Returns the current red, green, and blue color values on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_SetTextureAlphaMod( ... )`

Set an additional alpha value multiplied into render copy operations.

        SDL_SetTextureAlphaMod( $texture, 100 );

When this texture is rendered, during the copy operation the source alpha

value is modulated by this alpha value according to the following formula:

        srcA = srcA * (alpha / 255)

Alpha modulation is not always supported by the renderer; it will return -1 if alpha modulation is not supported.

Expected parameters include:

texture - the texture to update
alpha - the source alpha value multiplied into copy operations

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_GetTextureAlphaMod( ... )`

Get the additional alpha value multiplied into render copy operations.

        my $alpha = SDL_GetTextureAlphaMod( $texture );

Expected parameters include:

texture - the texture to query

Returns the current alpha value on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_SetTextureBlendMode( ... )`

Set the blend mode for a texture, used by SDL_RenderCopy( ... ).

If the blend mode is not supported, the closest supported mode is chosen and this function returns -1.

Expected parameters include:

texture - the texture to update
blendMode - the SDL_BlendMode to use for texture blending

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_GetTextureBlendMode( ... )`

Get the blend mode used for texture copy operations.

        SDL_GetTextureBlendMode( $texture, SDL_BLENDMODE_ADD );

Expected parameters include:

texture - the texture to query

Returns the current :blendMode on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_SetTextureScaleMode( ... )`

Set the scale mode used for texture scale operations.

        SDL_SetTextureScaleMode( $texture, $scaleMode );

If the scale mode is not supported, the closest supported mode is chosen.

Expected parameters include:

texture - The texture to update.
scaleMode - the SDL_ScaleMode to use for texture scaling.

Returns 0 on success, or -1 if the texture is not valid.

`SDL_GetTextureScaleMode( ... )`

Get the scale mode used for texture scale operations.

        my $ok = SDL_GetTextureScaleMode( $texture );

Expected parameters include:

texture - the texture to query.

Returns the current scale mode on success, or -1 if the texture is not valid.

`SDL_UpdateTexture( ... )`

Update the given texture rectangle with new pixel data.

        my $rect = SDL2::Rect->new( { x => 0, y => ..., w => $surface->w, h => $surface->h } );
        SDL_UpdateTexture( $texture, $rect, $surface->pixels, $surface->pitch );

The pixel data must be in the pixel format of the texture. Use SDL_QueryTexture( ... ) to query the pixel format of the texture.

This is a fairly slow function, intended for use with static textures that do not change often.

If the texture is intended to be updated often, it is preferred to create the texture as streaming and use the locking functions referenced below. While this function will work with streaming textures, for optimization reasons you may not get the pixels back if you lock the texture afterward.

Expected parameters include:

texture - the texture to update
rect - an SDL2::Rect structure representing the area to update, or undef to update the entire texture
pixels - the raw pixel data in the format of the texture
pitch - the number of bytes in a row of pixel data, including padding between lines

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_UpdateYUVTexture( ... )`

Update a rectangle within a planar YV12 or IYUV texture with new pixel data.

        SDL_UpdateYUVTexture( $texture, $rect, $yPlane, $yPitch, $uPlane, $uPitch, $vPlane, $vPitch );

You can use SDL_UpdateTexture( ... ) as long as your pixel data is a contiguous block of Y and U/V planes in the proper order, but this function is available if your pixel data is not contiguous.

Expected parameters include:

texture - the texture to update
rect - a pointer to the rectangle of pixels to update, or undef to update the entire texture
Yplane - the raw pixel data for the Y plane
Ypitch - the number of bytes between rows of pixel data for the Y plane
Uplane - the raw pixel data for the U plane
Upitch - the number of bytes between rows of pixel data for the U plane
Vplane - the raw pixel data for the V plane
Vpitch - the number of bytes between rows of pixel data for the V plane

Returns 0 on success or -1 if the texture is not valid; call SDL_GetError( ) for more information.

`SDL_UpdateNVTexture( ... )`

Update a rectangle within a planar NV12 or NV21 texture with new pixels.

        SDL_UpdateNVTexture( $texture, $rect, $yPlane, $yPitch, $uPlane, $uPitch );

You can use SDL_UpdateTexture( ... ) as long as your pixel data is a contiguous block of NV12/21 planes in the proper order, but this function is available if your pixel data is not contiguous.

Expected parameters include:

texture - the texture to update
rect - a pointer to the rectangle of pixels to update, or undef to update the entire texture.
Yplane - the raw pixel data for the Y plane.
Ypitch - the number of bytes between rows of pixel data for the Y plane.
UVplane - the raw pixel data for the UV plane.
UVpitch - the number of bytes between rows of pixel data for the UV plane.

Returns 0 on success, or -1 if the texture is not valid.

`SDL_LockTexture( ... )`

Lock a portion of the texture for write-only pixel access.

        SDL_LockTexture( $texture, $rect, $pixels, $pitch );

As an optimization, the pixels made available for editing don't necessarily contain the old texture data. This is a write-only operation, and if you need to keep a copy of the texture data you should do that at the application level.

You must use SDL_UpdateTexture( ... ) to unlock the pixels and apply any changes.

Expected parameters include:

texture - the texture to lock for access, which was created with SDL_TEXTUREACCESS_STREAMING
rect - an SDL2::Rect structure representing the area to lock for access; undef to lock the entire texture
pixels - this is filled in with a pointer to the locked pixels, appropriately offset by the locked area
pitch - this is filled in with the pitch of the locked pixels; the pitch is the length of one row in bytes

Returns 0 on success or a negative error code if the texture is not valid or was not created with SDL_TEXTUREACCESS_STREAMING; call SDL_GetError( ) for more information.

`SDL_LockTextureToSurface( ... )`

Lock a portion of the texture for write-only pixel access, and expose it as a SDL surface.

        my $surface = SDL_LockTextureSurface( $texture, $rect );

Besides providing an SDL2::Surface instead of raw pixel data, this function operates like SDL2::LockTexture.

You must use SDL_UnlockTexture( ... ) to unlock the pixels and apply any changes.

The returned surface is freed internally after calling SDL_UnlockTexture( ... ) or SDL_DestroyTexture( ... ). The caller should not free it.

Expected parameters include:

texture - the texture to lock for access, which was created with SDL_TEXTUREACCESS_STREAMING
rect - a pointer to the rectangle to lock for access. If the rect is undef, the entire texture will be locked

Returns the SDL2::Surface structure on success, or -1 if the texture is not valid or was not created with SDL_TEXTUREACCESS_STREAMING.

`SDL_UnlockTexture( ... )`

Unlock a texture, uploading the changes to video memory, if needed.

        SDL_UnlockTexture( $texture );

Warning: Please note that SDL_LockTexture( ... ) is intended to be write-only; it will not guarantee the previous contents of the texture will be provided. You must fully initialize any area of a texture that you lock before unlocking it, as the pixels might otherwise be uninitialized memory.

Which is to say: locking and immediately unlocking a texture can result in corrupted textures, depending on the renderer in use.

Expected parameters include:

texture - a texture locked by SDL_LockTexture( ... )

`SDL_RenderTargetSupported( ... )`

Determine whether a renderer supports the use of render targets.

        my $bool = SDL_RenderTargetSupported( $renderer );

Expected parameters include:

renderer - the renderer that will be checked

Returns true if supported or false if not.

`SDL_SetRenderTarget( ... )`

Set a texture as the current rendering target.

        SDL_SetRenderTarget( $renderer, $texture );

Before using this function, you should check the SDL_RENDERER_TARGETTEXTURE bit in the flags of SDL2::RendererInfo to see if render targets are supported.

The default render target is the window for which the renderer was created. To stop rendering to a texture and render to the window again, call this function with a undefined texture.

Expected parameters include:

renderer - the rendering context
texture - the targeted texture, which must be created with the SDL_TEXTUREACCESS_TARGET flag, or undef to render to the window instead of a texture.

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_GetRenderTarget( ... )`

Get the current render target.

        my $texture = SDL_GetRenderTarget( $renderer );

The default render target is the window for which the renderer was created, and is reported an undefined value here.

Expected parameters include:

renderer - the rendering context

Returns the current render target or undef for the default render target.

`SDL_RenderSetLogicalSize( ... )`

Set a device independent resolution for rendering.

        SDL_RenderSetLogicalSize( $renderer, 100, 100 );

This function uses the viewport and scaling functionality to allow a fixed logical resolution for rendering, regardless of the actual output resolution. If the actual output resolution doesn't have the same aspect ratio the output rendering will be centered within the output display.

If the output display is a window, mouse and touch events in the window will be filtered and scaled so they seem to arrive within the logical resolution.

If this function results in scaling or subpixel drawing by the rendering backend, it will be handled using the appropriate quality hints.

Expected parameters include:

renderer - the renderer for which resolution should be set
w - the width of the logical resolution
h - the height of the logical resolution

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderGetLogicalSize( ... )`

Get device independent resolution for rendering.

        my ($w, $h) = SDL_RenderGetLogicalSize( $renderer );

This may return 0 for w and h if the SDL2::Renderer has never had its logical size set by SDL_RenderSetLogicalSize( ... ) and never had a render target set.

Expected parameters include:

renderer - a rendering context

Returns the width and height.

`SDL_RenderSetIntegerScale( ... )`

Set whether to force integer scales for resolution-independent rendering.

        SDL_RenderSetIntegerScale( $renderer, 1 );

This function restricts the logical viewport to integer values - that is, when a resolution is between two multiples of a logical size, the viewport size is rounded down to the lower multiple.

Expected parameters include:

renderer - the renderer for which integer scaling should be set
enable - enable or disable the integer scaling for rendering

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderGetIntegerScale( ... )`

Get whether integer scales are forced for resolution-independent rendering.

        SDL_RenderGetIntegerScale( $renderer );

Expected parameters include:

renderer - the renderer from which integer scaling should be queried

Returns true if integer scales are forced or false if not and on failure; call SDL_GetError( ) for more information.

`SDL_RenderSetViewport( ... )`

Set the drawing area for rendering on the current target.

        SDL_RenderSetViewport( $renderer, $rect );

When the window is resized, the viewport is reset to fill the entire new window size.

Expected parameters include:

renderer - the rendering context
rect - the SDL2::Rect structure representing the drawing area, or undef to set the viewport to the entire target

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderGetViewport( ... )`

Get the drawing area for the current target.

        my $rect = SDL_RenderGetViewport( $renderer );

Expected parameters include:

renderer - the rendering context

Returns an SDL2::Rect structure filled in with the current drawing area.

`SDL_RenderSetClipRect( ... )`

Set the clip rectangle for rendering on the specified target.

        SDL_RenderSetClipRect( $renderer, $rect );

Expected parameters include:

renderer - the rendering context for which clip rectangle should be set
rect - an SDL2::Rect structure representing the clip area, relative to the viewport, or undef to disable clipping

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderGetClipRect( ... )`

Get the clip rectangle for the current target.

        my $rect = SDL_RenderGetClipRect( $renderer );

Expected parameters include:

renderer - the rendering context from which clip rectangle should be queried

Returns an SDL2::Rect structure filled in with the current clipping area or an empty rectangle if clipping is disabled.

`SDL_RenderIsClipEnabled( ... )`

Get whether clipping is enabled on the given renderer.

        my $tf = SDL_RenderIsClipEnabled( $renderer );

Expected parameters include:

renderer - the renderer from which clip state should be queried

Returns true if clipping is enabled or false if not; call SDL_GetError( ) for more information.

`SDL_RenderSetScale( ... )`

Set the drawing scale for rendering on the current target.

        SDL_RenderSetScale( $renderer, .5, 1 );

The drawing coordinates are scaled by the x/y scaling factors before they are used by the renderer. This allows resolution independent drawing with a single coordinate system.

If this results in scaling or subpixel drawing by the rendering backend, it will be handled using the appropriate quality hints. For best results use integer scaling factors.

Expected parameters include:

renderer - a rendering context
scaleX - the horizontal scaling factor
scaleY - the vertical scaling factor

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderGetScale( ... )`

Get the drawing scale for the current target.

        my ($scaleX, $scaleY) = SDL_RenderGetScale( $renderer );

Expected parameters include:

renderer - the renderer from which drawing scale should be queried

Returns the horizonal and vertical scaling factors.

`SDL_SetRenderDrawColor( ... )`

Set the color used for drawing operations (Rect, Line and Clear).

        SDL_SetRenderDrawColor( $renderer, 0, 0, 128, SDL_ALPHA_OPAQUE );

Set the color for drawing or filling rectangles, lines, and points, and for SDL_RenderClear( ... ).

Expected parameters include:

renderer - the rendering context
r - the red value used to draw on the rendering target
g - the green value used to draw on the rendering target
b - the blue value used to draw on the rendering target
a - the alpha value used to draw on the rendering target; usually SDL_ALPHA_OPAQUE (255). Use SDL_SetRenderDrawBlendMode to specify how the alpha channel is used

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_GetRenderDrawColor( ... )`

Get the color used for drawing operations (Rect, Line and Clear).

        my ($r, $g, $b, $a) = SDL_GetRenderDrawColor( $renderer );

Expected parameters include:

renderer - the rendering context

Returns red, green, blue, and alpha values on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_SetRenderDrawBlendMode( ... )`

Set the blend mode used for drawing operations (Fill and Line).

        SDL_SetRenderDrawBlendMode( $renderer, SDL_BLENDMODE_BLEND );

If the blend mode is not supported, the closest supported mode is chosen.

Expected parameters include:

renderer - the rendering context
blendMode - the SDL_BlendMode to use for blending

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_GetRenderDrawBlendMode( ... )`

Get the blend mode used for drawing operations.

        my $blendMode = SDL_GetRenderDrawBlendMode( $rendering );

Expected parameters include:

renderer - the rendering context

Returns the current :blendMode on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderClear( ... )`

Clear the current rendering target with the drawing color.

        SDL_RenderClear( $renderer );

This function clears the entire rendering target, ignoring the viewport and the clip rectangle.

renderer - the rendering context

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderDrawPoint( ... )`

Draw a point on the current rendering target.

        SDL_RenderDrawPoint( $renderer, 100, 100 );

SDL_RenderDrawPoint( ... ) draws a single point. If you want to draw multiple, use SDL_RenderDrawPoints( ... ) instead.

Expected parameters include:

renderer - the rendering context
x - the x coordinate of the point
y - the y coordinate of the point

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderDrawPoints( ... )`

Draw multiple points on the current rendering target.

        my @points = map { SDL2::Point->new( {x => int rand, y => int rand } ) } 1..1024;
        SDL_RenderDrawPoints( $renderer, @points );

renderer - the rendering context
points - an array of SDL2::Point structures that represent the points to draw

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderDrawLine( ... )`

Draw a line on the current rendering target.

        SDL_RenderDrawLine( $renderer, 300, 240, 340, 240 );

SDL_RenderDrawLine( ... ) draws the line to include both end points. If you want to draw multiple, connecting lines use SDL_RenderDrawLines( ... ) instead.

Expected parameters include:

renderer - the rendering context
x1 - the x coordinate of the start point
y1 - the y coordinate of the start point
x2 - the x coordinate of the end point
y2 - the y coordinate of the end point

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderDrawLines( ... )`

Draw a series of connected lines on the current rendering target.

        SDL_RenderDrawLines( $renderer, @points);

Expected parameters include:

renderer - the rendering context
points - an array of SDL2::Point structures representing points along the lines

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderDrawRect( ... )`

Draw a rectangle on the current rendering target.

        SDL_RenderDrawRect( $renderer, SDL2::Rect->new( { x => 100, y => 100, w => 100, h => 100 } ) );

Expected parameters include:

renderer - the rendering context
rect - an SDL2::Rect structure representing the rectangle to draw

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderDrawRects( ... )`

Draw some number of rectangles on the current rendering target.

        SDL_RenderDrawRects( $renderer,
                SDL2::Rect->new( { x => 100, y => 100, w => 100, h => 100 } ),
        SDL2::Rect->new( { x => 75,  y => 75,  w => 50,  h => 50 } )
    );

Expected parameters include:

renderer - the rendering context
rects - an array of SDL2::Rect structures representing the rectangles to be drawn

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderFillRect( ... )`

Fill a rectangle on the current rendering target with the drawing color.

        SDL_RenderFillRect( $renderer, SDL2::Rect->new( { x => 100, y => 100, w => 100, h => 100 } ) );

The current drawing color is set by SDL_SetRenderDrawColor( ... ), and the color's alpha value is ignored unless blending is enabled with the appropriate call to SDL_SetRenderDrawBlendMode( ... ).

Expected parameters include:

renderer - the rendering context
rect - the SDL2::Rect structure representing the rectangle to fill

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderFillRects( ... )`

Fill some number of rectangles on the current rendering target with the drawing color.

        SDL_RenderFillRects( $renderer,
                SDL2::Rect->new( { x => 100, y => 100, w => 100, h => 100 } ),
        SDL2::Rect->new( { x => 75,  y => 75,  w => 50,  h => 50 } )
    );

Expected parameters include:

renderer - the rendering context
rects - an array of SDL2::Rect structures representing the rectangles to be filled

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderCopy( ... )`

Copy a portion of the texture to the current rendering target.

        SDL_RenderCopy( $renderer, $blueShapes, $srcR, $destR );

The texture is blended with the destination based on its blend mode set with SDL_SetTextureBlendMode( ... ).

The texture color is affected based on its color modulation set by SDL_SetTextureColorMod( ... ).

The texture alpha is affected based on its alpha modulation set by SDL_SetTextureAlphaMod( ... ).

Expected parameters include:

renderer - the rendering context
texture - the source texture
srcrect - the source SDL2::Rect structure
dstrect - the destination SDL2::Rect structure; the texture will be stretched to fill the given rectangle

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderCopyEx( ... )`

Copy a portion of the texture to the current rendering, with optional rotation and flipping.

Copy a portion of the texture to the current rendering target, optionally rotating it by angle around the given center and also flipping it top-bottom and/or left-right.

The texture is blended with the destination based on its blend mode set with SDL_SetTextureBlendMode( ... ).

The texture color is affected based on its color modulation set by SDL_SetTextureColorMod( ... ).

The texture alpha is affected based on its alpha modulation set by SDL_SetTextureAlphaMod( ... ).

Expected parameters include:

renderer - the rendering context
texture - the source texture
srcrect - the source SDL2::Rect structure
dstrect - the destination SDL_Rect structure
angle - an angle in degrees that indicates the rotation that will be applied to dstrect, rotating it in a clockwise direction
center - a pointer to a point indicating the point around which dstrect will be rotated (if NULL, rotation will be done around dstrect.w / 2, dstrect.h / 2)
flip - a :rendererFlip value stating which flipping actions should be performed on the texture

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderDrawPointF( ... )`

Draw a point on the current rendering target at subpixel precision.

        SDL_RenderDrawPointF( $renderer, 25.5, 100.25 );

Expected parameters include:

renderer - The renderer which should draw a point.
x - The x coordinate of the point.
y - The y coordinate of the point.

Returns 0 on success, or -1 on error

`SDL_RenderDrawPointsF( ... )`

Draw multiple points on the current rendering target at subpixel precision.

        my @points = map { SDL2::Point->new( {x => int rand, y => int rand } ) } 1..1024;
        SDL_RenderDrawPointsF( $renderer, @points );

Expected parameters include:

renderer - The renderer which should draw multiple points
points - The points to draw

Returns 0 on success, or -1 on error; call SDL_GetError( ) for more information.

`SDL_RenderDrawLineF( ... )`

Draw a line on the current rendering target at subpixel precision.

        SDL_RenderDrawLineF( $renderer, 100, 100, 250, 100);

Expected parameters include:

renderer - The renderer which should draw a line.
x1 - The x coordinate of the start point.
y1 - The y coordinate of the start point.
x2 - The x coordinate of the end point.
y2 - The y coordinate of the end point.

Returns 0 on success, or -1 on error.

`SDL_RenderDrawLinesF( ... )`

Draw a series of connected lines on the current rendering target at subpixel precision.

        SDL_RenderDrawLines( $renderer, @points);

Expected parameters include:

renderer - The renderer which should draw multiple lines.
points - The points along the lines

Return 0 on success, or -1 on error.

`SDL_RenderDrawRectF( ... )`

Draw a rectangle on the current rendering target at subpixel precision.

        SDL_RenderDrawRectF( $renderer, $point);

Expected parameters include:

renderer - The renderer which should draw a rectangle.
rect - A pointer to the destination rectangle

Returns 0 on success, or -1 on error

`SDL_RenderDrawRectsF( ... )`

Draw some number of rectangles on the current rendering target at subpixel precision.

        SDL_RenderDrawRectsF( $renderer,
                SDL2::Rect->new( { x => 100, y => 100, w => 100, h => 100 } ),
        SDL2::Rect->new( { x => 75,  y => 75,  w => 50,  h => 50 } )
    );

Expected parameters include:

renderer - The renderer which should draw multiple rectangles.
rects - A pointer to an array of destination rectangles.

Returns 0 on success, or -1 on error.

`SDL_RenderFillRectF( ... )`

Fill a rectangle on the current rendering target with the drawing color at subpixel precision.

        SDL_RenderFillRectF( $renderer,
        SDL2::Rect->new( { x => 75,  y => 75,  w => 50,  h => 50 } )
    );

Expected parameters include:

renderer - The renderer which should fill a rectangle.
rect - A pointer to the destination rectangle

Returns 0 on success, or -1 on error.

`SDL_RenderFillRectsF( ... )`

Fill some number of rectangles on the current rendering target with the drawing color at subpixel precision.

        SDL_RenderFillRectsF( $renderer,
                SDL2::Rect->new( { x => 100, y => 100, w => 100, h => 100 } ),
        SDL2::Rect->new( { x => 75,  y => 75,  w => 50,  h => 50 } )
    );

Expected parameters include:

renderer - The renderer which should fill multiple rectangles.
rects - A pointer to an array of destination rectangles.

Returns 0 on success, or -1 on error.

`SDL_RenderCopyF( ... )`

Copy a portion of the texture to the current rendering target at subpixel precision.

Expected parameters include:

renderer - The renderer which should copy parts of a texture
texture - The source texture
srcrect - A pointer to the source rectangle
dstrect - A pointer to the destination rectangle

Returns 0 on success, or -1 on error.

`SDL_RenderCopyExF( ... )`

Copy a portion of the source texture to the current rendering target, with rotation and flipping, at subpixel precision.

renderer - The renderer which should copy parts of a texture
texture - The source texture
srcrect - A pointer to the source rectangle
dstrect - A pointer to the destination rectangle
angle - An angle in degrees that indicates the rotation that will be applied to dstrect, rotating it in a clockwise direction
center - A pointer to a point indicating the point around which dstrect will be rotated (if NULL, rotation will be done around dstrect.w/2, dstrect.h/2)
flip - A :rendererFlip value stating which flipping actions should be performed on the texture

Returns 0 on success, or -1 on error

`SDL_RenderReadPixels( ... )`

Read pixels from the current rendering target to an array of pixels.

        SDL_RenderReadPixels(
        $renderer,
        SDL2::Rect->new( { x => 0, y => 0, w => 640, h => 480 } ),
        SDL_PIXELFORMAT_RGB888,
        $surface->pixels, $surface->pitch
    );

WARNING: This is a very slow operation, and should not be used frequently.

pitch specifies the number of bytes between rows in the destination pixels data. This allows you to write to a subrectangle or have padded rows in the destination. Generally, pitch should equal the number of pixels per row in the `pixels` data times the number of bytes per pixel, but it might contain additional padding (for example, 24bit RGB Windows Bitmap data pads all rows to multiples of 4 bytes).

Expected parameters include:

renderer - the rendering context
rect - an SDL2::Rect structure representing the area to read
format - an :pixelFormatEnum value of the desired format of the pixel data, or 0 to use the format of the rendering target
pixels - pointer to the pixel data to copy into
pitch - the pitch of the pixels parameter

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_RenderPresent( ... )`

Update the screen with any rendering performed since the previous call.

        SDL_RenderPresent( $renderer );

SDL's rendering functions operate on a backbuffer; that is, calling a rendering function such as SDL_RenderDrawLine( ... ) does not directly put a line on the screen, but rather updates the backbuffer. As such, you compose your entire scene and *present* the composed backbuffer to the screen as a complete picture.

Therefore, when using SDL's rendering API, one does all drawing intended for the frame, and then calls this function once per frame to present the final drawing to the user.

The backbuffer should be considered invalidated after each present; do not assume that previous contents will exist between frames. You are strongly encouraged to call SDL_RenderClear( ... ) to initialize the backbuffer before starting each new frame's drawing, even if you plan to overwrite every pixel.

Expected parameters include:

renderer - the rendering context

`SDL_DestroyTexture( ... )`

Destroy the specified texture.

        SDL_DestroyTexture( $texture );

Passing undef or an otherwise invalid texture will set the SDL error message to "Invalid texture".

Expected parameters include:

texture - the texture to destroy

`SDL_DestroyRenderer( ... )`

Destroy the rendering context for a window and free associated textures.

        SDL_DestroyRenderer( $renderer );

Expected parameters include:

renderer - the rendering context

`SDL_RenderFlush( ... )`

Force the rendering context to flush any pending commands to the underlying rendering API.

        SDL_RenderFlush( $renderer );

You do not need to (and in fact, shouldn't) call this function unless you are planning to call into OpenGL/Direct3D/Metal/whatever directly in addition to using an SDL_Renderer.

This is for a very-specific case: if you are using SDL's render API, you asked for a specific renderer backend (OpenGL, Direct3D, etc), you set SDL_HINT_RENDER_BATCHING to "1", and you plan to make OpenGL/D3D/whatever calls in addition to SDL render API calls. If all of this applies, you should call SDL_RenderFlush( ... ) between calls to SDL's render API and the low-level API you're using in cooperation.

In all other cases, you can ignore this function. This is only here to get maximum performance out of a specific situation. In all other cases, SDL will do the right thing, perhaps at a performance loss.

This function is first available in SDL 2.0.10, and is not needed in 2.0.9 and earlier, as earlier versions did not queue rendering commands at all, instead flushing them to the OS immediately.

Expected parameters include:

renderer - the rendering context

Returns 0 on success or a negative error code on failure; call SDL_GetError( ) for more information.

`SDL_GL_BindTexture( ... )`

Bind an OpenGL/ES/ES2 texture to the current context.

        my ($texw, $texh) = SDL_GL_BindTexture( $texture );

This is for use with OpenGL instructions when rendering OpenGL primitives directly.

If not NULL, the returned width and height values suitable for the provided texture. In most cases, both will be 1.0, however, on systems that support the GL_ARB_texture_rectangle extension, these values will actually be the pixel width and height used to create the texture, so this factor needs to be taken into account when providing texture coordinates to OpenGL.

You need a renderer to create an SDL2::Texture, therefore you can only use this function with an implicit OpenGL context from SDL_CreateRenderer( ... ), not with your own OpenGL context. If you need control over your OpenGL context, you need to write your own texture-loading methods.

Also note that SDL may upload RGB textures as BGR (or vice-versa), and re-order the color channels in the shaders phase, so the uploaded texture may have swapped color channels.

Expected parameters include:

texture - the texture to bind to the current OpenGL/ES/ES2 context

Returns the texture's with and height on success, or -1 if the operation is not supported; call SDL_GetError( ) for more information.

`SDL_GL_UnbindTexture( ... )`

Unbind an OpenGL/ES/ES2 texture from the current context.

        SDL_GL_UnbindTexture( $texture );

See SDL_GL_BindTexture( ... ) for examples on how to use these functions.

Expected parameters include:

texture - the texture to unbind from the current OpenGL/ES/ES2 context

Returns 0 on success, or -1 if the operation is not supported.

`SDL_RenderGetMetalLayer( ... )`

Get the CAMetalLayer associated with the given Metal renderer.

        my $opaque = SDL_RenderGetMetalLayer( $renderer );

This function returns void *, so SDL doesn't have to include Metal's headers, but it can be safely cast to a CAMetalLayer *.

Expected parameters include:

renderer - the renderer to query

Returns CAMetalLayer* on success, or undef if the renderer isn't a Metal renderer.

`SDL_RenderGetMetalCommandEncoder( ... )`

Get the Metal command encoder for the current frame

        $opaque = SDL_RenderGetMetalCommandEncoder( $renderer );

This function returns void *, so SDL doesn't have to include Metal's headers, but it can be safely cast to an id<MTLRenderCommandEncoder>.

Expected parameters include:

renderer - the renderer to query

Returns id<MTLRenderCommandEncoder> on success, or undef if the renderer isn't a Metal renderer.

Defined Variables and Enumerations

Variables may be imported by name or with the :render tag. Enumerations may be imported with their given tags.

`SDL_RendererFlags`

Flags used when creating a rendering context.

SDL_RENDERER_SOFTWARE - The renderer is a software fallback
SDL_RENDERER_ACCELERATED - The renderer uses hardware acceleration
SDL_RENDERER_PRESENTVSYNC - Present is synchronized with the refresh rate
SDL_RENDERER_TARGETTEXTURE - The renderer supports rendering to texture

`SDL_ScaleMode`

The scaling mode for a texture.

SDL_ScaleModeNearest - nearest pixel sampling
SDL_ScaleModeLinear - linear filtering
SDL_ScaleModeBest - anisotropic filtering

`SDL_TextureAccess`

The access pattern allowed for a texture.

SDL_TEXTUREACCESS_STATIC - Changes rarely, not lockable
SDL_TEXTUREACCESS_STREAMING - Changes frequently, lockable
SDL_TEXTUREACCESS_TARGET - Texture can be used as a render target

`SDL_TextureModulate`

The texture channel modulation used in SDL_RenderCopy( ).

SDL_TEXTUREMODULATE_NONE - No modulation
SDL_TEXTUREMODULATE_COLOR - srcC = srcC * color
SDL_TEXTUREMODULATE_ALPHA - srcA = srcA * alpha

`SDL_RendererFlip`

Flip constants for SDL_RenderCopyEx

SDL_FLIP_NONE - Do not flip
SDL_FLIP_HORIZONTAL - flip horizontally
SDL_FLIP_VERTICAL - flip vertically

LICENSE

This library is free software; you can redistribute it and/or modify it under the terms found in the Artistic License 2. Other copyrights, terms, and conditions may apply to data transmitted through this module.

AUTHOR

Sanko Robinson <sanko@cpan.org>

To install SDL2::FFI, copy and paste the appropriate command in to your terminal.

cpanm

cpanm SDL2::FFI

CPAN shell

perl -MCPAN -e shell
install SDL2::FFI

For more information on module installation, please visit the detailed CPAN module installation guide.

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