| 1 | <HTML |
| 2 | ><HEAD |
| 3 | ><TITLE |
| 4 | >SDL_SetColorKey</TITLE |
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| 40 | >SDL Library Documentation</TH |
| 41 | ></TR |
| 42 | ><TR |
| 43 | ><TD |
| 44 | WIDTH="10%" |
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| 70 | WIDTH="100%"></DIV |
| 71 | ><H1 |
| 72 | ><A |
| 73 | NAME="SDLSETCOLORKEY" |
| 74 | ></A |
| 75 | >SDL_SetColorKey</H1 |
| 76 | ><DIV |
| 77 | CLASS="REFNAMEDIV" |
| 78 | ><A |
| 79 | NAME="AEN2045" |
| 80 | ></A |
| 81 | ><H2 |
| 82 | >Name</H2 |
| 83 | >SDL_SetColorKey -- Sets the color key (transparent pixel) in a blittable surface and |
| 84 | RLE acceleration.</DIV |
| 85 | ><DIV |
| 86 | CLASS="REFSYNOPSISDIV" |
| 87 | ><A |
| 88 | NAME="AEN2048" |
| 89 | ></A |
| 90 | ><H2 |
| 91 | >Synopsis</H2 |
| 92 | ><DIV |
| 93 | CLASS="FUNCSYNOPSIS" |
| 94 | ><A |
| 95 | NAME="AEN2049" |
| 96 | ></A |
| 97 | ><P |
| 98 | ></P |
| 99 | ><PRE |
| 100 | CLASS="FUNCSYNOPSISINFO" |
| 101 | >#include "SDL.h"</PRE |
| 102 | ><P |
| 103 | ><CODE |
| 104 | ><CODE |
| 105 | CLASS="FUNCDEF" |
| 106 | >int <B |
| 107 | CLASS="FSFUNC" |
| 108 | >SDL_SetColorKey</B |
| 109 | ></CODE |
| 110 | >(SDL_Surface *surface, Uint32 flag, Uint32 key);</CODE |
| 111 | ></P |
| 112 | ><P |
| 113 | ></P |
| 114 | ></DIV |
| 115 | ></DIV |
| 116 | ><DIV |
| 117 | CLASS="REFSECT1" |
| 118 | ><A |
| 119 | NAME="AEN2055" |
| 120 | ></A |
| 121 | ><H2 |
| 122 | >Description</H2 |
| 123 | ><P |
| 124 | > Sets the color key (transparent pixel) in a blittable surface and enables or |
| 125 | disables RLE blit acceleration.</P |
| 126 | ><P |
| 127 | >RLE acceleration can substantially speed up blitting of images with large |
| 128 | horizontal runs of transparent pixels (i.e., pixels that match the |
| 129 | <TT |
| 130 | CLASS="PARAMETER" |
| 131 | ><I |
| 132 | >key</I |
| 133 | ></TT |
| 134 | > value). The <TT |
| 135 | CLASS="PARAMETER" |
| 136 | ><I |
| 137 | >key</I |
| 138 | ></TT |
| 139 | > must be of the same pixel format as the <TT |
| 140 | CLASS="PARAMETER" |
| 141 | ><I |
| 142 | >surface</I |
| 143 | ></TT |
| 144 | >, <A |
| 145 | HREF="sdlmaprgb.html" |
| 146 | ><TT |
| 147 | CLASS="FUNCTION" |
| 148 | >SDL_MapRGB</TT |
| 149 | ></A |
| 150 | > is often useful for obtaining an acceptable value.</P |
| 151 | ><P |
| 152 | >If <TT |
| 153 | CLASS="PARAMETER" |
| 154 | ><I |
| 155 | >flag</I |
| 156 | ></TT |
| 157 | > is <TT |
| 158 | CLASS="LITERAL" |
| 159 | >SDL_SRCCOLORKEY</TT |
| 160 | > then |
| 161 | <TT |
| 162 | CLASS="PARAMETER" |
| 163 | ><I |
| 164 | >key</I |
| 165 | ></TT |
| 166 | > is the transparent pixel value in the source image of a |
| 167 | blit.</P |
| 168 | ><P |
| 169 | >If <TT |
| 170 | CLASS="PARAMETER" |
| 171 | ><I |
| 172 | >flag</I |
| 173 | ></TT |
| 174 | > is OR'd with |
| 175 | <TT |
| 176 | CLASS="LITERAL" |
| 177 | >SDL_RLEACCEL</TT |
| 178 | > then the surface will be draw using RLE |
| 179 | acceleration when drawn with |
| 180 | <A |
| 181 | HREF="sdlblitsurface.html" |
| 182 | >SDL_BlitSurface</A |
| 183 | >. The surface will |
| 184 | actually be encoded for RLE acceleration the first time |
| 185 | <A |
| 186 | HREF="sdlblitsurface.html" |
| 187 | >SDL_BlitSurface</A |
| 188 | > or |
| 189 | <A |
| 190 | HREF="sdldisplayformat.html" |
| 191 | >SDL_DisplayFormat</A |
| 192 | > is called on the |
| 193 | surface.</P |
| 194 | ><P |
| 195 | >If <TT |
| 196 | CLASS="PARAMETER" |
| 197 | ><I |
| 198 | >flag</I |
| 199 | ></TT |
| 200 | > is 0, this function clears |
| 201 | any current color key.</P |
| 202 | ></DIV |
| 203 | ><DIV |
| 204 | CLASS="REFSECT1" |
| 205 | ><A |
| 206 | NAME="AEN2076" |
| 207 | ></A |
| 208 | ><H2 |
| 209 | >Return Value</H2 |
| 210 | ><P |
| 211 | >This function returns <SPAN |
| 212 | CLASS="RETURNVALUE" |
| 213 | >0</SPAN |
| 214 | >, or |
| 215 | <SPAN |
| 216 | CLASS="RETURNVALUE" |
| 217 | >-1</SPAN |
| 218 | > if there was an error.</P |
| 219 | ></DIV |
| 220 | ><DIV |
| 221 | CLASS="REFSECT1" |
| 222 | ><A |
| 223 | NAME="AEN2081" |
| 224 | ></A |
| 225 | ><H2 |
| 226 | >See Also</H2 |
| 227 | ><P |
| 228 | ><A |
| 229 | HREF="sdlblitsurface.html" |
| 230 | ><TT |
| 231 | CLASS="FUNCTION" |
| 232 | >SDL_BlitSurface</TT |
| 233 | ></A |
| 234 | >, |
| 235 | <A |
| 236 | HREF="sdldisplayformat.html" |
| 237 | ><TT |
| 238 | CLASS="FUNCTION" |
| 239 | >SDL_DisplayFormat</TT |
| 240 | ></A |
| 241 | >, |
| 242 | <A |
| 243 | HREF="sdlmaprgb.html" |
| 244 | ><TT |
| 245 | CLASS="FUNCTION" |
| 246 | >SDL_MapRGB</TT |
| 247 | ></A |
| 248 | >, |
| 249 | <A |
| 250 | HREF="sdlsetalpha.html" |
| 251 | ><TT |
| 252 | CLASS="FUNCTION" |
| 253 | >SDL_SetAlpha</TT |
| 254 | ></A |
| 255 | ></P |
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| 301 | >SDL_SaveBMP</TD |
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| 315 | >SDL_SetAlpha</TD |
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| 321 | > |