3 <h3 id="TOP">Index</h3>
5 <ul><li><a href="#NAME">NAME</a></li>
6 <li><a href="#CATEGORY">CATEGORY</a></li>
7 <li><a href="#SYNOPSIS">SYNOPSIS</a></li>
8 <li><a href="#METHODS">METHODS</a>
9 <ul><li><a href="#get_video_surface">get_video_surface</a></li>
10 <li><a href="#get_video_info">get_video_info</a></li>
11 <li><a href="#video_driver_name">video_driver_name</a></li>
12 <li><a href="#list_modes_formats_flags">list_modes(formats,flags)</a></li>
13 <li><a href="#video_mode_ok_width_height_bpp_flags">video_mode_ok(width,height,bpp,flags)</a></li>
14 <li><a href="#set_video_mode_width_height_bpp_flag">set_video_mode(width,height,bpp,flags)</a>
15 <ul><li><a href="#List_of_avalaibles_flags">List of avalaibles flags</a></li>
18 <li><a href="#update_rect_surface_x_y_width_height">update_rect(surface,x,y,width,height)</a></li>
19 <li><a href="#update_rects_surface_rects">update_rects(surface,rects) </a></li>
20 <li><a href="#flip_surface">flip(surface)</a></li>
21 <li><a href="#set_colors_surface_start_colors">set_colors(surface,start,colors)</a></li>
22 <li><a href="#set_palette_surface_flags_start_colo">set_palette(surface,flags,start,colors)</a></li>
23 <li><a href="#set_gamma_r_g_b">set_gamma(r,g,b)</a></li>
24 <li><a href="#get_gamma_ramp_rt_gt_bt">get_gamma_ramp(rt,gt,bt)</a></li>
25 <li><a href="#set_gamma_ramp_rt_gt_bt">set_gamma_ramp(rt,gt,bt)</a></li>
26 <li><a href="#map_RGB_pixel_format_r_g_b">map_RGB(pixel_format,r,g,b)</a></li>
27 <li><a href="#map_RGBA_pixel_format_r_g_b_a">map_RGBA(pixel_format,r,g,b,a)</a></li>
28 <li><a href="#get_RGB_pixel_format_pixel">get_RGB(pixel_format,pixel)</a></li>
29 <li><a href="#get_RGBA_pixel_format_pixel">get_RGBA(pixel_format,pixel)</a></li>
30 <li><a href="#create_RGB_surface_from">create_RGB_surface_from ***</a></li>
31 <li><a href="#lock_surface_surface">lock_surface(surface)</a></li>
32 <li><a href="#unlock_surface_surface">unlock_surface(surface)</a></li>
33 <li><a href="#convert_surface_surface_format_flags">convert_surface(surface,format,flags)</a></li>
34 <li><a href="#display_format">display_format</a></li>
35 <li><a href="#display_format_alpha">display_format_alpha</a></li>
36 <li><a href="#load_BMP_filename">load_BMP(filename)</a></li>
37 <li><a href="#save_BMP_surface_filename">save_BMP(surface,filename)</a></li>
38 <li><a href="#set_color_key_surface_flag_key">set_color_key(surface,flag,key)</a></li>
39 <li><a href="#set_alpha_surface_flag_key">set_alpha(surface,flag,key)</a></li>
40 <li><a href="#set_clip_rect_surface_rect">set_clip_rect(surface,rect)</a></li>
41 <li><a href="#get_clip_rect_surface_rect">get_clip_rect(surface,rect)</a></li>
42 <li><a href="#blit_surface_src_src_rect_dest_dest_">blit_surface(src,src_rect,dest,dest_rect)</a></li>
43 <li><a href="#fill_rect_dest_dest_rect_pixel">fill_rect(dest,dest_rect,pixel)</a></li>
44 <li><a href="#GL_load_library_path">GL_load_library(path)</a></li>
45 <li><a href="#GL_get_proc_address_proc">GL_get_proc_address(proc)</a></li>
46 <li><a href="#GL_get_attribute_attr">GL_get_attribute(attr)</a></li>
47 <li><a href="#GL_set_attribute_attr_value">GL_set_attribute(attr,value)</a></li>
48 <li><a href="#GL_swap_buffers">GL_swap_buffers</a></li>
49 <li><a href="#GL_attr_to_be_coded">GL_attr *** to be coded</a></li>
50 <li><a href="#lock_YUV_overlay_overlay">lock_YUV_overlay(overlay)</a></li>
51 <li><a href="#unlock_YUV_overlay_overlay">unlock_YUV_overlay(overlay)</a></li>
52 <li><a href="#display_YUV_overlay_overlay_dstrect">display_YUV_overlay(overlay,dstrect)</a></li>
55 <li><a href="#SEE_ALSO">SEE ALSO</a>
56 <ul><li><a href="#Category_Objects">Category Objects</a>
61 <!-- INDEX END --><a href="assets/Video.png" target="_blank"><img src="assets/Video.png" style="height: 160px" alt="Video.png"/></a><hr />
63 <h1 id="NAME">NAME</h1><p><a href="#TOP" class="toplink">Top</a></p>
64 <div id="NAME_CONTENT">
65 <p>SDL::Video - Bindings to the video category in SDL API</p>
68 <h1 id="CATEGORY">CATEGORY</h1><p><a href="#TOP" class="toplink">Top</a></p>
69 <div id="CATEGORY_CONTENT">
73 <h1 id="SYNOPSIS">SYNOPSIS</h1><p><a href="#TOP" class="toplink">Top</a></p>
74 <div id="SYNOPSIS_CONTENT">
80 # the size of the window box or the screen resolution if fullscreen
81 my $screen_width = 800;
82 my $screen_height = 600;
84 SDL::init(SDL_INIT_VIDEO);
87 my $screen_surface = SDL::Video::set_video_mode($screen_width, $screen_height, 32, SDL_SWSURFACE);
89 # drawing something somewhere
90 my $mapped_color = SDL::Video::map_RGB($screen_surface->format(), 0, 0, 255); # blue
91 SDL::Video::fill_rect($screen_surface,
92 SDL::Rect->new($screen_width / 4, $screen_height / 4,
93 $screen_width / 2, $screen_height / 2), $mapped_color);
95 # update an area on the screen so its visible
96 SDL::Video::update_rect($screen_surface, 0, 0, $screen_width, $screen_height);
98 sleep(5); # just to have time to see it
105 <h1 id="METHODS">METHODS</h1><p><a href="#TOP" class="toplink">Top</a></p>
106 <div id="METHODS_CONTENT">
109 <h2 id="get_video_surface">get_video_surface</h2>
110 <div id="get_video_surface_CONTENT">
111 <pre> my $surface = SDL::Video::get_video_surface();
114 <p>This function returns the current display <a href="/SDL-Surface.html">SDL::Surface</a>. If SDL is doing format conversion on the display surface, this
115 function returns the publicly visible surface, not the real video surface.</p>
117 <pre> # somewhere after you set the video mode
118 my $surface = SDL::Video::get_video_surface();
120 printf( "our screen is %d pixels wide and %d pixels high\n", $surface->w, $surface->h );
125 <h2 id="get_video_info">get_video_info</h2>
126 <div id="get_video_info_CONTENT">
127 <pre> my $video_info = SDL::Video::get_video_info();
130 <p>This function returns a read-only <a href="/SDL-VideoInfo.html">SDL::VideoInfo</a> containing information about the video hardware. If it is called before
131 <a href="#set_video_mode_width_height_bpp_flag">SDL::Video::set_video_mode</a>, the <code>vfmt</code> member of the returned structure will contain the pixel
132 format of the <strong>best</strong> video mode. </p>
137 use SDL::PixelFormat;
139 SDL::init(SDL_INIT_VIDEO);
141 my $video_info = SDL::Video::get_video_info();
143 printf( "we can have %dbits per pixel\n", $video_info->vfmt->BitsPerPixel );
150 <h2 id="video_driver_name">video_driver_name</h2>
151 <div id="video_driver_name_CONTENT">
152 <pre> my $driver_name = SDL::Video::video_driver_name();
155 <p>This function will return the name of the initialized video driver up to a maximum of 1024 characters. The driver name is a simple one
156 word identifier like <code>"x11"</code>, <code>"windib"</code> or <code>"directx"</code>.</p>
157 <p><strong>Note</strong>: Some platforms allow selection of the video driver through the <code>SDL_VIDEODRIVER</code> environment variable. </p>
162 SDL::init(SDL_INIT_VIDEO);
164 print SDL::Video::video_driver_name() . "\n";
171 <h2 id="list_modes_formats_flags">list_modes(formats,flags)</h2>
172 <div id="list_modes_formats_flags_CONTENT">
173 <pre> my @modes = @{ SDL::Video::list_modes( $pixel_format, $flags ) };
176 <p>Returns a ref to an array of available screen dimensions for the given format and video flags,
177 or it return undef if no modes are available.</p>
182 use SDL::PixelFormat;
185 SDL::init(SDL_INIT_VIDEO);
187 my $video_info = SDL::Video::get_video_info();
189 my @modes = @{ SDL::Video::list_modes($video_info->vfmt, SDL_NOFRAME) };
193 print("available modes:\n");
194 foreach my $index ( @modes )
196 printf("%03d: %d x %d\n", $index, $modes[$index]->w, $modes[$index]->h );
201 printf("%s video modes available\n", $modes[0]);
209 <h2 id="video_mode_ok_width_height_bpp_flags">video_mode_ok(width,height,bpp,flags)</h2>
210 <div id="video_mode_ok_width_height_bpp_flags-2">
211 <pre> my $bpp_ok = SDL::Video::video_mode_ok( $width, $height, $bpp, $flags );
214 <p>This function is used to check whether the requested mode is supported by the current video device. The arguments passed to this function
215 are the same as those you would pass to <a href="#set_video_mode_width_height_bpp_flag">SDL::Video::set_video_mode</a>.
216 It returns <code>0</code> if the mode is not supported at all, otherwise the suggested <code>bpp</code>.</p>
221 SDL::init(SDL_INIT_VIDEO);
223 my $video_mode_ok = SDL::Video::video_mode_ok( 800, 600, 32, SDL_SWSURFACE );
225 unless($video_mode_ok)
227 printf("this video mode ist not supported\n" );
238 <h2 id="set_video_mode_width_height_bpp_flag">set_video_mode(width,height,bpp,flags)</h2>
239 <div id="set_video_mode_width_height_bpp_flag-2">
240 <pre> my $surface = SDL::Video::set_video_mode( 800, 600, 32, SDL_SWSURFACE|SDL_DOUBLEBUF|SDL_FULLSCREEN);
243 <p>Sets up a video mode with the specified width, height, bits-per-pixel and flags.
244 <code>set_video_mode</code> returns a <a href="/SDL-Surface.html">SDL::Surface</a> on success otherwise it returns undef on error, the error message is retrieved
245 using <code>SDL::get_error</code>.</p>
248 <h3 id="List_of_avalaibles_flags">List of avalaibles flags</h3>
249 <div id="List_of_avalaibles_flags_CONTENT">
251 <dt><code>SDL_SWSURFACE</code></dt>
253 <p>Create the video surface in system memory</p>
255 <dt><code>SDL_HWSURFACE</code></dt>
257 <p>Create the video surface in video memory</p>
259 <dt><code>SDL_ASYNCBLIT</code></dt>
261 <p>Enables the use of asynchronous updates of the display surface.
262 This will usually slow down blitting on single CPU machines, but may provide a speed increase on SMP systems.</p>
264 <dt><code>SDL_ANYFORMAT</code></dt>
266 <p>Normally, if a video surface of the requested bits-per-pixel (bpp) is not available, SDL will emulate one with a shadow surface.
267 Passing <code>SDL_ANYFORMAT</code> prevents this and causes SDL to use the video surface, regardless of its pixel depth.</p>
269 <dt><code>SDL_HWPALETTE</code></dt>
271 <p>Give SDL exclusive palette access. Without this flag you may not always get the colors you request with SDL::set_colors or SDL::set_palette.</p>
273 <dt><code>SDL_DOUBLEBUF</code></dt>
275 <p>Enable hardware double buffering; only valid with <code>SDL_HWSURFACE</code>. Calling <a href="#flip_surface">SDL::Video::flip</a> will flip the buffers and update
277 All drawing will take place on the surface that is not displayed at the moment.
278 If double buffering could not be enabled then <a href="#flip_surface">SDL::Video::flip</a> will just perform a
279 <a href="#update_rect_surface_x_y_width_height">SDL::Video::update_rect</a> on the entire screen.</p>
281 <dt><code>SDL_FULLSCREEN</code></dt>
283 <p>SDL will attempt to use a fullscreen mode. If a hardware resolution change is not possible (for whatever reason),
284 the next higher resolution will be used and the display window centered on a black background.</p>
286 <dt><code>SDL_OPENGL</code></dt>
288 <p>Create an OpenGL rendering context. You should have previously set OpenGL video attributes with
289 <a href="#GL_set_attribute_attr_value">SDL::Video::GL_set_attribute</a>.</p>
291 <dt><code>SDL_OPENGLBLIT</code></dt>
293 <p>Create an OpenGL rendering context, like above, but allow normal blitting operations.
294 The screen (2D) surface may have an alpha channel, and SDL::update_rects must be used for updating changes to the screen surface.
295 NOTE: This option is kept for compatibility only, and will be removed in next versions. Is not recommended for new code.</p>
297 <dt><code>SDL_RESIZABLE</code></dt>
299 <p>Create a resizable window.
300 When the window is resized by the user a <code>SDL_VIDEORESIZE</code> event is generated and
301 <a href="#set_video_mode_width_height_bpp_flag">SDL::Video::set_video_mode</a> can be called again with the new size.</p>
303 <dt><code>SDL_NOFRAME</code></dt>
305 <p>If possible, SDL_NOFRAME causes SDL to create a window with no title bar or frame decoration.
306 Fullscreen modes automatically have this flag set.</p>
309 <p><strong>Note 1</strong>: Use <code>SDL_SWSURFACE</code> if you plan on doing per-pixel manipulations, or blit surfaces with alpha channels, and require a high framerate.
310 When you use hardware surfaces (by passing the flag <code>SDL_HWSURFACE</code> as parameter), SDL copies the surfaces from video memory to system memory
311 when you lock them, and back when you unlock them. This can cause a major performance hit. Be aware that you may request a hardware surface,
312 but receive a software surface because the video driver doesn't support hardware surface. Many platforms can only provide a hardware surface
313 when using <code>SDL_FULLSCREEN</code>. The <code>SDL_HWSURFACE</code> flag is best used when the surfaces you'll be blitting can also be stored in video memory.</p>
314 <p><strong>Note 2</strong>: If you want to control the position on the screen when creating a windowed surface, you may do so by setting the environment
315 variables <code>SDL_VIDEO_CENTERED=center</code> or <code>SDL_VIDEO_WINDOW_POS=x,y</code>. You can also set them via <code>SDL::putenv</code>.</p>
316 <p><strong>Note 3</strong>: This function should be called in the main thread of your application.</p>
317 <p><strong>User note 1</strong>: Some have found that enabling OpenGL attributes like <code>SDL_GL_STENCIL_SIZE</code> (the stencil buffer size) before the video mode has
318 been set causes the application to simply ignore those attributes, while enabling attributes after the video mode has been set works fine.</p>
319 <p><strong>User note 2</strong>: Also note that, in Windows, setting the video mode resets the current OpenGL context. You must execute again the OpenGL
320 initialization code (set the clear color or the shade model, or reload textures, for example) after calling SDL::set_video_mode. In Linux,
321 however, it works fine, and the initialization code only needs to be executed after the first call to
322 <a href="#set_video_mode_width_height_bpp_flag">SDL::Video::set_video_mode</a> (although there is no harm in executing the initialization code after
323 each call to <a href="#set_video_mode_width_height_bpp_flag">SDL::Video::set_video_mode</a>, for example for a multiplatform application). </p>
326 <h2 id="update_rect_surface_x_y_width_height">update_rect(surface,x,y,width,height)</h2>
327 <div id="update_rect_surface_x_y_width_height-2">
328 <pre> update_rect( $surface, $left, $top, $width, $height );
331 <p>Makes sure the given area is updated on the given screen.
332 The rectangle must be confined within the screen boundaries because there's no clipping.
333 update_rect doesn't returns any value.</p>
334 <p><strong>Note</strong>: This function should not be called while screen is locked by <a href="#lock_surface_surface">SDL::Video::lock_surface</a></p>
335 <p><strong>Note2</strong>: If <code>x</code>, <code>y</code>, <code>width</code> and <code>height</code> are all equal to 0, <code>update_rect</code> will update the entire screen. </p>
336 <p>For an example see <a href="#SYNOPSIS">SYNOPSIS</a></p>
339 <h2 id="update_rects_surface_rects">update_rects(surface,rects) </h2>
340 <div id="update_rects_surface_rects_CONTENT">
341 <pre> update_rects( $surface, @rects );
344 <p>Makes sure the given list of rectangles is updated on the given screen.
345 The rectangle must be confined within the screen boundaries because there's no clipping.
346 <code>update_rects</code> doesn't returns any value.</p>
347 <p><strong>Note</strong>: This function should not be called while screen is locked by <a href="#lock_surface_surface">SDL::Video::lock_surface</a>.</p>
354 # the size of the window box or the screen resolution if fullscreen
355 my $screen_width = 800;
356 my $screen_height = 600;
358 SDL::init(SDL_INIT_VIDEO);
361 my $screen_surface = SDL::Video::set_video_mode($screen_width, $screen_height, 32, SDL_SWSURFACE);
363 # drawing the whole screen blue
364 my $mapped_color = SDL::Video::map_RGB($screen_surface->format(), 0, 0, 255); # blue
365 SDL::Video::fill_rect($screen_surface,
366 SDL::Rect->new(0, 0, $screen_width, $screen_height),
370 push(@rects, SDL::Rect->new(200, 0, 400, 600));
371 push(@rects, SDL::Rect->new( 0, 150, 800, 300));
373 # updating parts of the screen (should look like a cross)
374 SDL::Video::update_rects($screen_surface, @rects);
383 <h2 id="flip_surface">flip(surface)</h2>
384 <div id="flip_surface_CONTENT">
385 <pre> $flip = SDL::Video::flip( $screen_surface );
388 <p>On hardware that supports double-buffering, this function sets up a flip and returns.
389 The hardware will wait for vertical retrace, and then swap video buffers before the next video surface blit or lock will return.
390 On hardware that doesn't support double-buffering or if <code>SDL_SWSURFACE</code> was set, this is equivalent to calling
391 <code>SDL::Video::update_rect( $screen, 0, 0, 0, 0 )</code>.</p>
392 <p>A software screen surface is also updated automatically when parts of a SDL window are redrawn, caused by overlapping windows or by
393 restoring from an iconified state. As a result there is no proper double buffer behavior in windowed mode for a software screen, in
394 contrast to a full screen software mode.</p>
395 <p>The <code>SDL_DOUBLEBUF</code> flag must have been passed to <code>SDL::Video::set_video_mode</code>, when setting the video mode for this function to
396 perform hardware flipping.</p>
397 <p><code>flip</code> returns <code>0</code> on success or <code>-1</code> on error.</p>
398 <p><strong>Note</strong>: If you want to swap the buffers of an initialized OpenGL context, use the function <code>SDL::Video::GL_swap_buffers</code> instead. </p>
404 # the size of the window box or the screen resolution if fullscreen
405 my $screen_width = 800;
406 my $screen_height = 600;
408 SDL::init(SDL_INIT_VIDEO);
411 my $screen_surface = SDL::Video::set_video_mode($screen_width, $screen_height, 32, SDL_DOUBLEBUF|SDL_FULLSCREEN);
413 # do some video operations here
415 # doing page flipping
416 unless( SDL::Video::flip($screen_surface) == 0 )
418 printf( STDERR "failed to swap buffers: %s\n", SDL::get_error() );
426 <h2 id="set_colors_surface_start_colors">set_colors(surface,start,colors)</h2>
427 <div id="set_colors_surface_start_colors_CONT">
428 <pre> $set_colors = SDL::Video::set_colors( $surface, $start, $color1, $color2, ... )
431 <p>Sets a portion of the colormap for the given 8-bit surface. </p>
432 <p>When surface is the surface associated with the current display, the display colormap will be updated with the requested colors.
433 If <code>SDL_HWPALETTE</code> was set in <code>SDL::Video::set_video_mode</code> flags, <code>SDL::Video::set_colors</code> will always return 1, and the palette is
434 guaranteed to be set the way you desire, even if the window colormap has to be warped or run under emulation.
435 The color components of a <a href="/SDL-Color.html">SDL::Color</a> structure are 8-bits in size, giving you a total of 2563 = 16777216 colors.
436 Palettized (8-bit) screen surfaces with the <code>SDL_HWPALETTE</code> flag have two palettes, a logical palette that is used for mapping blits to/from
437 the surface and a physical palette (that determines how the hardware will map the colors to the display).
438 <code>SDL::Video::set_colors</code> modifies both palettes (if present), and is equivalent to calling <code>SDL::Video::set_palette</code> with the flags set to
439 ( <code>SDL_LOGPAL | SDL_PHYSPAL</code> ). </p>
440 <p>If <code>surface</code> is not a palettized surface, this function does nothing, returning 0.
441 If all of the colors were set as passed to <code>SDL::Video::set_colors</code>, it will return 1.
442 If not all the color entries were set exactly as given, it will return 0, and you should look at the surface palette to determine the
443 actual color palette.</p>
446 <h2 id="set_palette_surface_flags_start_colo">set_palette(surface,flags,start,colors)</h2>
447 <div id="set_palette_surface_flags_start_colo-2">
448 <pre> $set_palette = set_palette( $surface, $flags, $start, $color1, $color2, ... );
451 <p>Sets a portion of the palette for the given 8-bit surface.</p>
452 <p>Palettized (8-bit) screen surfaces with the <code>SDL_HWPALETTE</code> flag have two palettes, a logical palette that is used for mapping blits to/from
453 the surface and a physical palette (that determines how the hardware will map the colors to the display).
454 Non screen surfaces have a logical palette only. <code>SDL::Video::blit</code> always uses the logical palette when blitting surfaces (if it has to
455 convert between surface pixel formats). Because of this, it is often useful to modify only one or the other palette to achieve various
456 special color effects (e.g., screen fading, color flashes, screen dimming).</p>
457 <p>This function can modify either the logical or physical palette by specifying <code>SDL_LOGPAL</code> or <code>SDL_PHYSPAL</code> the in the flags parameter.</p>
458 <p>When surface is the surface associated with the current display, the display colormap will be updated with the requested colors.
459 If <code>SDL_HWPALETTE</code> was set in <code>SDL::Video::set_video_mode</code> flags, <code>SDL::Video::set_palette</code> will always return 1, and the palette is
460 guaranteed to be set the way you desire, even if the window colormap has to be warped or run under emulation.
461 The color components of a <code>SDL::Color</code> structure are 8-bits in size, giving you a total of 2563 = 16777216 colors. </p>
462 <p>If <code>surface</code> is not a palettized surface, this function does nothing, returning <code>0</code>. If all of the colors were set as passed to <code>set_palette</code>,
463 it will return <code>1</code>. If not all the color entries were set exactly as given, it will return <code>0</code>, and you should look at the surface palette
464 to determine the actual color palette.</p>
467 <h2 id="set_gamma_r_g_b">set_gamma(r,g,b)</h2>
468 <div id="set_gamma_r_g_b_CONTENT">
469 <pre> $set_gamma = SDL::Video::set_gamma( $red_gamma, $green_gamma, $blue_gamma );
472 <p>Sets the "gamma function" for the display of each color component. Gamma controls the brightness/contrast of colors displayed on the screen.
473 A gamma value of 1.0 is identity (i.e., no adjustment is made).</p>
474 <p>This function adjusts the gamma based on the "gamma function" parameter, you can directly specify lookup tables for gamma adjustment
475 with SDL::set_gamma_ramp.</p>
476 <p><strong>Note</strong>: Not all display hardware is able to change gamma.</p>
477 <p><code>SDL::Video::set_gamma</code> returns <code>-1</code> on error.</p>
478 <p><strong>Warning</strong>: Under Linux (X.org Gnome and Xfce), gamma settings affects the entire display (including the desktop)! </p>
484 use Time::HiRes qw( usleep );
486 # the size of the window box or the screen resolution if fullscreen
487 my $screen_width = 800;
488 my $screen_height = 600;
490 SDL::init(SDL_INIT_VIDEO);
493 my $screen_surface = SDL::Video::set_video_mode($screen_width, $screen_height, 32, SDL_SWSURFACE);
495 # drawing something somewhere
496 my $mapped_color = SDL::Video::map_RGB($screen_surface->format(), 128, 128, 128); # gray
497 SDL::Video::fill_rect($screen_surface,
498 SDL::Rect->new($screen_width / 4, $screen_height / 4, $screen_width / 2, $screen_height / 2),
501 # update the whole screen
502 SDL::Video::update_rect($screen_surface, 0, 0, $screen_width, $screen_height);
508 SDL::Video::set_gamma( 1 - $_ / 20, 1, 1 );
514 SDL::Video::set_gamma( $_ / 20, 1, 1 );
518 SDL::Video::set_gamma( 1, 1, 1 );
527 <h2 id="get_gamma_ramp_rt_gt_bt">get_gamma_ramp(rt,gt,bt)</h2>
528 <div id="get_gamma_ramp_rt_gt_bt_CONTENT">
529 <pre> $get_gamma_ramp = SDL::Video::get_gamma_ramp( \@red_table, \@green_table, \@blue_table );
532 <p>Gets the gamma translation lookup tables currently used by the display. Each table is an array of 256 Uint16 values.
533 SDL::get_gamma_ramp returns -1 on error.</p>
537 SDL::init(SDL_INIT_VIDEO);
539 my (@red, @green, @blue);
541 my $ret = SDL::Video::get_gamma_ramp( \@red, \@green, \@blue );
545 print( "an error occoured" );
549 printf( "for gamma = 1.0: red=0x%04X, green=0x%04X, blue=0x%04X\n", $red[255], $green[255], $blue[255] );
550 printf( "for gamma = 0.5: red=0x%04X, green=0x%04X, blue=0x%04X\n", $red[127], $green[127], $blue[127] );
551 printf( "for gamma = 0.0: red=0x%04X, green=0x%04X, blue=0x%04X\n", $red[0], $green[0], $blue[0] );
559 <h2 id="set_gamma_ramp_rt_gt_bt">set_gamma_ramp(rt,gt,bt)</h2>
560 <div id="set_gamma_ramp_rt_gt_bt_CONTENT">
561 <pre> $set_gamma_ramp = SDL::Video::set_gamma_ramp( \@red_table, \@green_table, \@blue_table );
564 <p>Sets the gamma lookup tables for the display for each color component. Each table is an array ref of 256 Uint16 values, representing a
565 mapping between the input and output for that channel.
566 The input is the index into the array, and the output is the 16-bit gamma value at that index, scaled to the output color precision.
567 You may pass NULL to any of the channels to leave them unchanged.</p>
568 <p>This function adjusts the gamma based on lookup tables, you can also have the gamma calculated based on a "gamma function" parameter
569 with <code>SDL::Video::set_gamma</code>.</p>
570 <p>Not all display hardware is able to change gamma.
571 <code>SDL::Video::set_gamma_ramp</code> returns <code>-1</code> on error (or if gamma adjustment is not supported).</p>
576 SDL::init(SDL_INIT_VIDEO);
578 my (@red, @green, @blue);
580 my $ret = SDL::Video::get_gamma_ramp( \@red, \@green, \@blue );
584 $ret = SDL::Video::set_gamma_ramp( \@red, \@green, \@blue );
586 $ret = SDL::Video::get_gamma_ramp( \@red, \@green, \@blue );
590 print( "an error occoured" );
594 printf( "for gamma = 1.0: red=0x%04X, green=0x%04X, blue=0x%04X\n", $red[255], $green[255], $blue[255] );
595 printf( "for gamma = 0.5: red=0x%04X, green=0x%04X, blue=0x%04X\n", $red[127], $green[127], $blue[127] );
596 printf( "for gamma = 0.0: red=0x%04X, green=0x%04X, blue=0x%04X\n", $red[0], $green[0], $blue[0] );
604 <h2 id="map_RGB_pixel_format_r_g_b">map_RGB(pixel_format,r,g,b)</h2>
605 <div id="map_RGB_pixel_format_r_g_b_CONTENT">
606 <pre> $pixel = SDL::Video::map_RGB( $pixel_format, $r, $g, $b );
609 <p>Maps the RGB color value to the specified <a href="/SDL-PixelFormat.html">SDL::PixelFormat</a> and returns the pixel value as a 32-bit int.
610 If the format has a palette (8-bit) the index of the closest matching color in the palette will be returned.
611 If the specified pixel format has an alpha component it will be returned as all 1 bits (fully opaque). </p>
612 <p><code>SDL::Video::map_RGB</code> returns a pixel value best approximating the given RGB color value for a given pixel format.
613 If the <a href="/SDL-PixelFormat.html">SDL::PixelFormat</a>'s bpp (color depth) is less than 32-bpp then the unused upper bits of the return value can safely be ignored
614 (e.g., with a 16-bpp format the return value can be assigned to a Uint16, and similarly a Uint8 for an 8-bpp format).</p>
617 use SDL::PixelFormat;
620 SDL::init(SDL_INIT_VIDEO);
622 my $screen_surface = SDL::Video::set_video_mode(640, 480, 16, SDL_SWSURFACE);
623 # ^-- 16 bits per pixel
629 printf( "for 24bpp it is: 0x%02X 0x%02X 0x%02X\n", $r, $g, $b);
631 my $_16bit = SDL::Video::map_RGB( $screen_surface->format, $r, $g, $b );
633 # 16bpp is 5 bits red, 6 bits green and 5 bits blue
634 # we will obtain the values for each color and calculating them back to 24bit color system
635 $r = (($_16bit & 0b1111100000000000) >> 11) / 0b11111 * 0b11111111;
636 $g = (($_16bit & 0b0000011111100000) >> 5) / 0b111111 * 0b11111111;
637 $b = ($_16bit & 0b0000000000011111) / 0b11111 * 0b11111111;
639 printf( "for 16bpp it is: 0x%02X 0x%02X 0x%02X\n", $r, $g, $b );
641 # so color #9CDC67 becomes #9CDE62
648 <h2 id="map_RGBA_pixel_format_r_g_b_a">map_RGBA(pixel_format,r,g,b,a)</h2>
649 <div id="map_RGBA_pixel_format_r_g_b_a_CONTEN">
650 <p>Maps the RGBA color value to the specified SDL::pixel_format and returns the pixel value as a 32-bit int.
651 If the format has a palette (8-bit) the index of the closest matching color in the palette will be returned.
652 If the specified pixel format has no alpha component the alpha value will be ignored (as it will be in formats with a palette). </p>
653 <p>A pixel value best approximating the given RGBA color value for a given pixel format.
654 If the pixel format bpp (color depth) is less than 32-bpp then the unused upper bits of the return value can safely be ignored (e.g.,
655 with a 16-bpp format the return value can be assigned to a Uint16, and similarly a Uint8 for an 8-bpp format).</p>
658 <h2 id="get_RGB_pixel_format_pixel">get_RGB(pixel_format,pixel)</h2>
659 <div id="get_RGB_pixel_format_pixel_CONTENT">
660 <p>Returns RGB values from a pixel in the specified pixel format.
661 This function uses the entire 8-bit [0..255] range when converting color components from pixel formats with less than 8-bits per RGB
662 component (e.g., a completely white pixel in 16-bit RGB565 format would return [0xff, 0xff, 0xff] not [0xf8, 0xfc, 0xf8]).</p>
665 <h2 id="get_RGBA_pixel_format_pixel">get_RGBA(pixel_format,pixel)</h2>
666 <div id="get_RGBA_pixel_format_pixel_CONTENT">
667 <p>Gets RGBA values from a pixel in the specified pixel format.
668 This function uses the entire 8-bit [0..255] range when converting color components from pixel formats with less than 8-bits per RGB
669 component (e.g., a completely white pixel in 16-bit RGB565 format would return [0xff, 0xff, 0xff] not [0xf8, 0xfc, 0xf8]).</p>
670 <p>If the surface has no alpha component, the alpha will be returned as 0xff (100% opaque). </p>
673 <h2 id="create_RGB_surface_from">create_RGB_surface_from ***</h2>
674 <div id="create_RGB_surface_from_CONTENT">
675 <p>Creates an empty SDL::Surface from pixel data
676 Allocate an empty surface (must be called after SDL::set_video_mode)
677 If bitsPerPixel is 8 an empty palette is allocated for the surface, otherwise a 'packed-pixel' SDL::pixel_format is created using the
678 [RGBA]mask's provided (see SDL::pixel_format). The flags specifies the type of surface that should be created, it is an OR'd combination
679 of the following possible values. </p>
681 <dt>SDL_SWSURFACE</dt>
683 <p>SDL will create the surface in system memory.
684 This improves the performance of pixel level access, however you may not be able to take advantage of some types of hardware blitting.</p>
686 <dt>SDL_HWSURFACE</dt>
688 <p>SDL will attempt to create the surface in video memory.
689 This will allow SDL to take advantage of Video->Video blits (which are often accelerated).</p>
691 <dt>SDL_SRCCOLORKEY</dt>
693 <p>This flag turns on color keying for blits from this surface.
694 If SDL_HWSURFACE is also specified and color keyed blits are hardware-accelerated, then SDL will attempt to place the surface in video memory.
695 If the screen is a hardware surface and color keyed blits are hardware-accelerated then the SDL_HWSURFACE flag will be set.
696 Use SDL_SetColorKey to set or clear this flag after surface creation.</p>
698 <dt>SDL_SRCALPHA</dt>
700 <p>This flag turns on alpha-blending for blits from this surface.
701 If SDL_HWSURFACE is also specified and alpha-blending blits are hardware-accelerated,
702 then the surface will be placed in video memory if possible.
703 If the screen is a hardware surface and alpha-blending blits are hardware-accelerated then the SDL_HWSURFACE flag will be set.
704 Use SDL_SetAlpha to set or clear this flag after surface creation.</p>
711 <p>[RGBA]mask are the bitmasks used to extract that colour from a pixel.
712 For instance, Rmask being FF000000 means the red data is stored in the most significant byte.
713 Using zeros for the RGB masks sets a default value, based on the depth. (e.g. SDL::create_RGB_surface(flags,w,h,32,0,0,0,0);).
714 However, using zero for the Amask results in an Amask of 0.
715 It returns a SDL::Surface on success or undef on error.
716 Notes: If an alpha-channel is specified (that is, if Amask is nonzero), then the SDL_SRCALPHA flag is automatically set.
717 You may remove this flag by calling SDL::set_alpha after surface creation.
718 Also, if the SDL_HWSURFACE flag is set on the returned surface, its format might not match the requested format. </p>
719 <p>Notes: Sometimes specifying an Alpha mask value could cause strange results.
720 This can be worked around by setting the Amask parameter to 0, but still including the SDL_SRCALPHA flag, and then using SDL::set_alpha,
721 also with the SDL_SRCALPHA flag. </p>
724 <h2 id="lock_surface_surface">lock_surface(surface)</h2>
725 <div id="lock_surface_surface_CONTENT">
726 <p>SDL::lock_surface sets up the given SDL::surface for directly accessing the pixels.
727 Between calls to SDL::lock_surface and SDL::unlock_surface, you can write to and read from surface->pixels, using the pixel format stored
728 in surface->format.
729 Once you are done accessing the surface, you should use SDL::unlock_surface to release the lock.</p>
730 <p>Not all surfaces require locking. If SDL::MUSTLOCK(surface) evaluates to 0, then reading and writing pixels to the surface can be performed
731 at any time, and the pixel format of the surface will not change.
732 No operating system or library calls should be made between the lock/unlock pairs, as critical system locks may be held during this time.
733 SDL::lock_surface returns 0 on success or -1 on error.</p>
734 <p>Note : Since SDL 1.1.8, the surface locks are recursive. This means that you can lock a surface multiple times, but each lock must have
735 a matching unlock.</p>
738 <h2 id="unlock_surface_surface">unlock_surface(surface)</h2>
739 <div id="unlock_surface_surface_CONTENT">
740 <p>Surfaces that were previously locked using SDL::lock_surface must be unlocked with SDL::unlock_surface. Surfaces should be unlocked as
742 SDL::unlock_surface doesn't return anything.</p>
743 <p>Note : Since 1.1.8, the surface locks are recursive. See <code>SDL::lock_surface</code> for more information. </p>
746 <h2 id="convert_surface_surface_format_flags">convert_surface(surface,format,flags)</h2>
747 <div id="convert_surface_surface_format_flags-2">
748 <p>Creates a new SDL::surface of the specified SDL::pixel_format, and then copies and maps the given surface to it.
749 It is also useful for making a copy of a surface.</p>
750 <p>The flags parameter is passed to SDL::create_RGB_surface and has those semantics.
751 This function is used internally by SDL::display_format.
752 This function can only be called after SDL::init. </p>
753 <p>it returns a SDL::surface on success or undef on error.</p>
756 <h2 id="display_format">display_format</h2>
757 <div id="display_format_CONTENT">
758 <p>Converts a surface to the display format </p>
761 <h2 id="display_format_alpha">display_format_alpha</h2>
762 <div id="display_format_alpha_CONTENT">
763 <p>Converts a surface to the display format </p>
766 <h2 id="load_BMP_filename">load_BMP(filename)</h2>
767 <div id="load_BMP_filename_CONTENT">
768 <p>Loads a SDL::surface from a named Windows BMP file.
769 SDL::load_BMP returns a SDL::surface on success or undef on error.</p>
770 <p>Note: When loading a 24-bit Windows BMP file, pixel data points are loaded as blue, green, red, and NOT red, green, blue (as one might expect). </p>
780 <h2 id="save_BMP_surface_filename">save_BMP(surface,filename)</h2>
781 <div id="save_BMP_surface_filename_CONTENT">
782 <p>Saves the given SDL::Surface surface as a Windows BMP file named filename.
783 it returns 0 on success or -1 on error.</p>
786 <h2 id="set_color_key_surface_flag_key">set_color_key(surface,flag,key)</h2>
787 <div id="set_color_key_surface_flag_key_CONTE">
788 <p>Sets the color key (transparent pixel) in a blittable surface and enables or disables RLE blit acceleration.</p>
789 <p>RLE acceleration can substantially speed up blitting of images with large horizontal runs of transparent pixels (i.e., pixels that match
791 The key must be of the same pixel format as the surface, SDL::map_RGB is often useful for obtaining an acceptable value.
792 If flag is SDL_SRCCOLORKEY then key is the transparent pixel value in the source image of a blit.</p>
793 <p>If flag is OR'd with SDL_RLEACCEL then the surface will be drawn using RLE acceleration when drawn with SDL::Blit_surface.
794 The surface will actually be encoded for RLE acceleration the first time SDL::blit_surface or SDL::display_format is called on the surface.
795 If flag is 0, this function clears any current color key. </p>
796 <p>SDL::set_color_key returns 0 on success or -1 on error.</p>
803 <h2 id="set_alpha_surface_flag_key">set_alpha(surface,flag,key)</h2>
804 <div id="set_alpha_surface_flag_key_CONTENT">
805 <p>SDL::set_alpha is used for setting the per-surface alpha value and/or enabling and disabling alpha blending.</p>
806 <p>The surface parameter specifies which SDL::surface whose alpha attributes you wish to adjust.
807 flags is used to specify whether alpha blending should be used (SDL_SRCALPHA) and whether the surface should use RLE acceleration for
808 blitting (SDL_RLEACCEL).
809 flags can be an OR'd combination of these two options, one of these options or 0.
810 If SDL_SRCALPHA is not passed as a flag then all alpha information is ignored when blitting the surface.
811 The alpha parameter is the per-surface alpha value; a surface need not have an alpha channel to use per-surface alpha and blitting can
812 still be accelerated with SDL_RLEACCEL.</p>
813 <p>Note: The per-surface alpha value of 128 is considered a special case and is optimised, so it's much faster than other per-surface values.</p>
814 <p>Alpha affects surface blitting in the following ways: </p>
816 <dt>RGBA->RGB with SDL_SRCALPHA</dt>
818 <p>The source is alpha-blended with the destination, using the alpha channel.
819 SDL_SRCCOLORKEY and the per-surface alpha are ignored.</p>
821 <dt>RGBA->RGB without SDL_SRCALPHA</dt>
823 <p>The RGB data is copied from the source. The source alpha channel and the per-surface alpha value are ignored.
824 If SDL_SRCCOLORKEY is set, only the pixels not matching the colorkey value are copied.</p>
826 <dt>RGB->RGBA with SDL_SRCALPHA</dt>
828 <p>The source is alpha-blended with the destination using the per-surface alpha value.
829 If SDL_SRCCOLORKEY is set, only the pixels not matching the colorkey value are copied.
830 The alpha channel of the copied pixels is set to opaque.</p>
832 <dt>RGB->RGBA without SDL_SRCALPHA</dt>
834 <p>The RGB data is copied from the source and the alpha value of the copied pixels is set to opaque.
835 If SDL_SRCCOLORKEY is set, only the pixels not matching the colorkey value are copied.</p>
837 <dt>RGBA->RGBA with SDL_SRCALPHA</dt>
839 <p>The source is alpha-blended with the destination using the source alpha channel.
840 The alpha channel in the destination surface is left untouched. SDL_SRCCOLORKEY is ignored.</p>
842 <dt>RGBA->RGBA without SDL_SRCALPHA</dt>
844 <p>The RGBA data is copied to the destination surface.
845 If SDL_SRCCOLORKEY is set, only the pixels not matching the colorkey value are copied.</p>
847 <dt>RGB->RGB with SDL_SRCALPHA</dt>
849 <p>The source is alpha-blended with the destination using the per-surface alpha value.
850 If SDL_SRCCOLORKEY is set, only the pixels not matching the colorkey value are copied.</p>
852 <dt>RGB->RGB without SDL_SRCALPHA</dt>
854 <p>The RGB data is copied from the source.
855 If SDL_SRCCOLORKEY is set, only the pixels not matching the colorkey value are copied.</p>
858 <p>Note: When blitting, the presence or absence of SDL_SRCALPHA is relevant only on the source surface, not the destination.
859 Note: Note that RGBA->RGBA blits (with SDL_SRCALPHA set) keep the alpha of the destination surface. This means that you cannot compose
860 two arbitrary RGBA surfaces this way and get the result you would expect from "overlaying" them; the destination alpha will work as a mask.</p>
861 <p>Note: Also note that per-pixel and per-surface alpha cannot be combined; the per-pixel alpha is always used if available. </p>
862 <p>SDL::set_alpha returns 0 on success or -1 on error.</p>
865 <h2 id="set_clip_rect_surface_rect">set_clip_rect(surface,rect)</h2>
866 <div id="set_clip_rect_surface_rect_CONTENT">
867 <p>Sets the clipping rectangle for the given SDL::surface. When this surface is the destination of a blit, only the area within the clip
868 rectangle will be drawn into.
869 The rectangle pointed to by rect will be clipped to the edges of the surface so that the clip rectangle for a surface can never fall
870 outside the edges of the surface.
871 If rect is NULL the clipping rectangle will be set to the full size of the surface.
872 SDL::set_clip_rect doesn't returns anything.</p>
875 <h2 id="get_clip_rect_surface_rect">get_clip_rect(surface,rect)</h2>
876 <div id="get_clip_rect_surface_rect_CONTENT">
877 <p>Gets the clipping rectangle for the given SDL::surface. When this surface is the destination of a blit, only the area within the clip
878 rectangle is drawn into.
879 The rectangle pointed to by rect will be filled with the clipping rectangle of the surface.
880 SDL::get_clip_rect doesn't returns anything;</p>
887 <h2 id="blit_surface_src_src_rect_dest_dest_">blit_surface(src,src_rect,dest,dest_rect)</h2>
888 <div id="blit_surface_src_src_rect_dest_dest_-2">
889 <p>This performs a fast blit from the given source SDL::surface to the given destination SDL::surface.
890 The width and height in srcrect determine the size of the copied rectangle. Only the position is used in the dstrect (the width and height
891 are ignored). Blits with negative dstrect coordinates will be clipped properly.
892 If srcrect is NULL, the entire surface is copied. If dstrect is NULL, then the destination position (upper left corner) is (0, 0).
893 The final blit rectangle is saved in dstrect after all clipping is performed (srcrect is not modified).
894 The blit function should not be called on a locked surface. I.e. when you use your own drawing functions you may need to lock a surface,
895 but this is not the case with SDL::blit_surface. Like most surface manipulation functions in SDL, it should not be used together with OpenGL.</p>
896 <p>The results of blitting operations vary greatly depending on whether SDL_SRCALPHA is set or not. See SDL::set_alpha for an explanation of
897 how this affects your results. Colorkeying and alpha attributes also interact with surface blitting.
898 SDL::blit_surface doesn't returns anything.</p>
901 <h2 id="fill_rect_dest_dest_rect_pixel">fill_rect(dest,dest_rect,pixel)</h2>
902 <div id="fill_rect_dest_dest_rect_pixel_CONTE">
903 <p>This function performs a fast fill of the given SDL::rectangle with the given SDL::pixel_format. If dstrect is NULL, the whole surface
904 will be filled with color.</p>
905 <p>The color should be a pixel of the format used by the surface, and can be generated by the SDL::MapRGB or SDL::map_RGBA functions.
906 If the color value contains an alpha value then the destination is simply "filled" with that alpha information, no blending takes place.</p>
907 <p>If there is a clip rectangle set on the destination (set via SDL::set_clip_rect), then this function will clip based on the intersection
908 of the clip rectangle and the dstrect rectangle, and the dstrect rectangle will be modified to represent the area actually filled.</p>
909 <p>If you call this on the video surface (ie: the value of SDL::get_video_surface()) you may have to update the video surface to see the
910 result. This can happen if you are using a shadowed surface that is not double buffered in Windows XP using build 1.2.9. </p>
911 <p>SDL::fill_rect returns 0 on success or -1 on error.</p>
914 <h2 id="GL_load_library_path">GL_load_library(path)</h2>
915 <div id="GL_load_library_path_CONTENT">
916 <p>If you wish, you may load the OpenGL library from the given path at runtime, this must be done before SDL::set_video_mode is called.
917 The path of the GL library is passed to SDL::GL_load_library and it returns 0 on success, or -1 on an error. You must then use
918 SDL::GL_get_proc_address to retrieve function pointers to GL functions. </p>
919 <p>SDL::GL_load_library returns 0 on success or -1 or error.</p>
922 <h2 id="GL_get_proc_address_proc">GL_get_proc_address(proc)</h2>
923 <div id="GL_get_proc_address_proc_CONTENT">
924 <p>Returns the address of the GL function proc, or NULL if the function is not found. If the GL library is loaded at runtime, with
925 SDL::GL_load_library, then all GL functions must be retrieved this way. Usually this is used to retrieve function pointers to OpenGL
926 extensions. Note that this function needs an OpenGL context to function properly, so it should be called after SDL::set_video_mode
927 has been called (with the SDL_OPENGL flag).</p>
928 <p>OpenGL function pointers must be declared APIENTRY . This will ensure the proper calling convention is followed on platforms where this
929 matters (Win32) thereby avoiding stack corruption. In a Win32 build environment, APIENTRY should be defined as __stdcall. </p>
930 <p>it returns undef if the function is not found.</p>
933 <h2 id="GL_get_attribute_attr">GL_get_attribute(attr)</h2>
934 <div id="GL_get_attribute_attr_CONTENT">
935 <p>It returns SDL/OpenGL attribute attr . This is useful after a call to SDL::set_video_mode to check whether your attributes have been set
937 SDL::GL_get_attribute returns undef if the attribute is not found.</p>
940 <h2 id="GL_set_attribute_attr_value">GL_set_attribute(attr,value)</h2>
941 <div id="GL_set_attribute_attr_value_CONTENT">
942 <p>This function sets the given OpenGL attribute attr to value. The requested attributes will take effect after a call to SDL::set_video_mode.
943 You should use SDL::GL_get_attribute to check the values after a SDL::set_video_mode call, since the values obtained can differ from the
945 See SDL_GLattr for the full list of available attributes.
946 SDL::GL_set_attribute returns 0 on success or -1 on error.</p>
947 <p>Note : The SDL_DOUBLEBUF flag is not required to enable double buffering when setting an OpenGL video mode. Double buffering is enabled
948 or disabled using the SDL_GL_DOUBLEBUFFER attribute. </p>
951 <h2 id="GL_swap_buffers">GL_swap_buffers</h2>
952 <div id="GL_swap_buffers_CONTENT">
953 <p>Swap the OpenGL buffers, if double-buffering is supported.
954 SDL::GL_swap_buffers doesn't returns any value.</p>
957 <h2 id="GL_attr_to_be_coded">GL_attr *** to be coded</h2>
958 <div id="GL_attr_to_be_coded_CONTENT">
965 <h2 id="lock_YUV_overlay_overlay">lock_YUV_overlay(overlay)</h2>
966 <div id="lock_YUV_overlay_overlay_CONTENT">
967 <p>Much the same as <code>SDL::lock_surface</code>, SDL::lock_YUV_overlay locks the overlay for direct access to pixel data.
968 It returns 0 on success or -1 on error.</p>
971 <h2 id="unlock_YUV_overlay_overlay">unlock_YUV_overlay(overlay)</h2>
972 <div id="unlock_YUV_overlay_overlay_CONTENT">
973 <p>The opposite to <code>SDL::lock_YUV_overlay</code>. Unlocks a previously locked overlay. An overlay must be unlocked before it can be displayed.
974 It returns 0 on success or -1 on error.</p>
977 <h2 id="display_YUV_overlay_overlay_dstrect">display_YUV_overlay(overlay,dstrect)</h2>
978 <div id="display_YUV_overlay_overlay_dstrect_">
979 <p>Blit the overlay to the display surface specified when the overlay was created. The SDL::rect structure, dstrect, specifies a rectangle
980 on the display where the overlay is drawn. The .x and .y fields of dstrect specify the upper left location in display coordinates.
981 The overlay is scaled (independently in x and y dimensions) to the size specified by dstrect, and is optimized for 2x scaling</p>
982 <p>It returns 0 on success or -1 on error.</p>
989 <h1 id="SEE_ALSO">SEE ALSO</h1><p><a href="#TOP" class="toplink">Top</a></p>
990 <div id="SEE_ALSO_CONTENT">
993 <h2 id="Category_Objects">Category Objects</h2>
994 <div id="Category_Objects_CONTENT">
995 <p><a href="/SDL-Surface.html">SDL::Surface</a>, <a href="/SDL-Overlay.html">SDL::Overlay</a>, <a href="/SDL-Color.html">SDL::Color</a>,
996 <a href="/SDL-Rect.html">SDL::Rect</a>, <a href="/SDL-Palette.html">SDL::Palette</a>, <a href="/SDL-PixelFormat.html">SDL::PixelFormat</a>,
997 <a href="/SDL-VideoInfo.html">SDL::VideoInfo</a></p>