1al_set_new_display_option(3) al_set_new_display_option(3)
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6 al_set_new_display_option - Allegro 5 API
7
9 #include <allegro5/allegro.h>
10 void al_set_new_display_option(int option, int value, int importance)
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14 Set an extra display option, to be used when creating new displays on
15 the calling thread. Display options differ from display flags, and
16 specify some details of the context to be created within the window it‐
17 self. These mainly have no effect on Allegro itself, but you may want
18 to specify them, for example if you want to use multisampling.
19 The 'importance' parameter can be either:
21 · ALLEGRO_REQUIRE - The display will not be created if the setting can
23 not be met.
24 · ALLEGRO_SUGGEST - If the setting is not available, the display will
26 be created anyway with a setting as close as possible to the request‐
27 ed one. You can query the actual value used in that case by calling
28 al_get_display_option(3) after the display has been created.
29 · ALLEGRO_DONTCARE - If you added a display option with one of the
31 above two settings before, it will be removed again. Else this does
32 nothing.
33 The supported options are:
35 ALLEGRO_COLOR_SIZE
37 This can be used to ask for a specific bit depth. For example
38 to force a 16-bit framebuffer set this to 16.
39 ALLEGRO_RED_SIZE, ALLEGRO_GREEN_SIZE, ALLEGRO_BLUE_SIZE, ALLEGRO_AL‐
41 PHA_SIZE
42 Individual color component size in bits.
43 ALLEGRO_RED_SHIFT, ALLEGRO_GREEN_SHIFT, ALLEGRO_BLUE_SHIFT, ALLEGRO_AL‐
45 PHA_SHIFT
46 Together with the previous settings these can be used to specify
47 the exact pixel layout the display should use. Normally there
48 is no reason to use these.
49 ALLEGRO_ACC_RED_SIZE, ALLEGRO_ACC_GREEN_SIZE, ALLEGRO_ACC_BLUE_SIZE,
51 ALLEGRO_ACC_ALPHA_SIZE
52 This can be used to define the required accumulation buffer
53 size.
54 ALLEGRO_STEREO
56 Whether the display is a stereo display.
57 ALLEGRO_AUX_BUFFERS
59 Number of auxiliary buffers the display should have.
60 ALLEGRO_DEPTH_SIZE
62 How many depth buffer (z-buffer) bits to use.
63 ALLEGRO_STENCIL_SIZE
65 How many bits to use for the stencil buffer.
66 ALLEGRO_SAMPLE_BUFFERS
68 Whether to use multisampling (1) or not (0).
69 ALLEGRO_SAMPLES
71 If the above is 1, the number of samples to use per pixel. Else
72 0.
73 ALLEGRO_RENDER_METHOD:
75 0 if hardware acceleration is not used with this display.
76 ALLEGRO_FLOAT_COLOR
78 Whether to use floating point color components.
79 ALLEGRO_FLOAT_DEPTH
81 Whether to use a floating point depth buffer.
82 ALLEGRO_SINGLE_BUFFER
84 Whether the display uses a single buffer (1) or another update
85 method (0).
86 ALLEGRO_SWAP_METHOD
88 If the above is 0, this is set to 1 to indicate the display is
89 using a copying method to make the next buffer in the flip chain
90 available, or to 2 to indicate a flipping or other method.
91 ALLEGRO_COMPATIBLE_DISPLAY
93 Indicates if Allegro's graphics functions can use this display.
94 If you request a display not useable by Allegro, you can still
95 use for example OpenGL to draw graphics.
96 ALLEGRO_UPDATE_DISPLAY_REGION
98 Set to 1 if the display is capable of updating just a region,
99 and 0 if calling al_update_display_region(3) is equivalent to
100 al_flip_display(3).
101 ALLEGRO_VSYNC
103 Set to 1 to tell the driver to wait for vsync in al_flip_dis‐
104 play(3), or to 2 to force vsync off. The default of 0 means
105 that Allegro does not try to modify the vsync behavior so it may
106 be on or off. Note that even in the case of 1 or 2 it is possi‐
107 ble to override the vsync behavior in the graphics driver so you
108 should not rely on it.
109 ALLEGRO_MAX_BITMAP_SIZE
111 When queried this returns the maximum size (width as well as
112 height) a bitmap can have for this display. Calls to al_cre‐
113 ate_bitmap(3) or al_load_bitmap(3) for bitmaps larger than this
114 size will fail. It does not apply to memory bitmaps which al‐
115 ways can have arbitrary size (but are slow for drawing).
116 ALLEGRO_SUPPORT_NPOT_BITMAP
118 Set to 1 if textures used for bitmaps on this display can have a
119 size which is not a power of two. This is mostly useful if you
120 use Allegro to load textures as otherwise only power-of-two tex‐
121 tures will be used internally as bitmap storage.
122 ALLEGRO_CAN_DRAW_INTO_BITMAP
124 Set to 1 if you can use al_set_target_bitmap(3) on bitmaps of
125 this display to draw into them. If this is not the case soft‐
126 ware emulation will be used when drawing into display bitmaps
127 (which can be very slow).
128 ALLEGRO_SUPPORT_SEPARATE_ALPHA
130 This is set to 1 if the al_set_separate_blender(3) function is
131 supported. Otherwise the alpha parameters will be ignored.
132 ALLEGRO_AUTO_CONVERT_BITMAPS
134 This is on by default. It causes any existing memory bitmaps
135 with the ALLEGRO_CONVERT_BITMAP flag to be converted to a dis‐
136 play bitmap of the newly created display with the option set.
137 Since: 5.1.0
139 ALLEGRO_SUPPORTED_ORIENTATIONS
141 This is a bit-combination of the orientations supported by the
142 application. The orientations are the same as for al_get_dis‐
143 play_orientation(3) with the additional possibilities:
144 · ALLEGRO_DISPLAY_ORIENTATION_PORTRAIT
146 · ALLEGRO_DISPLAY_ORIENTATION_LANDSCAPE
148 · ALLEGRO_DISPLAY_ORIENTATION_ALL
150 PORTRAIT means only the two portrait orientations are supported,
152 LANDSCAPE means only the two landscape orientations and ALL al‐
153 lows all four orientations. When the orientation changes be‐
154 tween a portrait and a landscape orientation the display needs
155 to be resized. This is done by sending an ALLEGRO_EVENT_DIS‐
156 PLAY_RESIZE(3) message which should be handled by calling al_ac‐
157 knowledge_resize(3).
158 Since: 5.1.0
160 ALLEGRO_OPENGL_MAJOR_VERSION
162 Request a specific OpenGL major version.
163 Since: 5.1.13
165 ALLEGRO_OPENGL_MINOR_VERSION
167 Request a specific OpenGL minor version.
168 Since: 5.1.13
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172 al_set_new_display_flags(3), al_get_display_option(3)
173Allegro reference manual al_set_new_display_option(3)