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Added new docs for SDL 1.2.1
author Sam Lantinga <slouken@lokigames.com>
date Sun, 10 Jun 2001 19:31:57 +0000
parents 74212992fb08
children e5bc29de3f0a
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54:028447a8a758 55:55f1f1b3e27d
2 ><HEAD 2 ><HEAD
3 ><TITLE 3 ><TITLE
4 >SDL_BlitSurface</TITLE 4 >SDL_BlitSurface</TITLE
5 ><META 5 ><META
6 NAME="GENERATOR" 6 NAME="GENERATOR"
7 CONTENT="Modular DocBook HTML Stylesheet Version 1.61 7 CONTENT="Modular DocBook HTML Stylesheet Version 1.64
8 "><LINK 8 "><LINK
9 REL="HOME" 9 REL="HOME"
10 TITLE="SDL Library Documentation" 10 TITLE="SDL Library Documentation"
11 HREF="index.html"><LINK 11 HREF="index.html"><LINK
12 REL="UP" 12 REL="UP"
71 >SDL_BlitSurface</A 71 >SDL_BlitSurface</A
72 ></H1 72 ></H1
73 ><DIV 73 ><DIV
74 CLASS="REFNAMEDIV" 74 CLASS="REFNAMEDIV"
75 ><A 75 ><A
76 NAME="AEN1806" 76 NAME="AEN1883"
77 ></A 77 ></A
78 ><H2 78 ><H2
79 >Name</H2 79 >Name</H2
80 >SDL_BlitSurface&nbsp;--&nbsp;This performs a fast blit from the source surface to the destination surface.</DIV 80 >SDL_BlitSurface&nbsp;--&nbsp;This performs a fast blit from the source surface to the destination surface.</DIV
81 ><DIV 81 ><DIV
82 CLASS="REFSYNOPSISDIV" 82 CLASS="REFSYNOPSISDIV"
83 ><A 83 ><A
84 NAME="AEN1809" 84 NAME="AEN1886"
85 ></A 85 ></A
86 ><H2 86 ><H2
87 >Synopsis</H2 87 >Synopsis</H2
88 ><DIV 88 ><DIV
89 CLASS="FUNCSYNOPSIS" 89 CLASS="FUNCSYNOPSIS"
90 ><A 90 ><A
91 NAME="AEN1810" 91 NAME="AEN1887"
92 ></A 92 ></A
93 ><P 93 ><P
94 ></P 94 ></P
95 ><PRE 95 ><PRE
96 CLASS="FUNCSYNOPSISINFO" 96 CLASS="FUNCSYNOPSISINFO"
110 ></DIV 110 ></DIV
111 ></DIV 111 ></DIV
112 ><DIV 112 ><DIV
113 CLASS="REFSECT1" 113 CLASS="REFSECT1"
114 ><A 114 ><A
115 NAME="AEN1816" 115 NAME="AEN1893"
116 ></A 116 ></A
117 ><H2 117 ><H2
118 >Description</H2 118 >Description</H2
119 ><P 119 ><P
120 >This performs a fast blit from the source surface to the destination surface.</P 120 >This performs a fast blit from the source surface to the destination surface.</P
168 >srcrect</I 168 >srcrect</I
169 ></TT 169 ></TT
170 > is not modified).</P 170 > is not modified).</P
171 ><P 171 ><P
172 >The blit function should not be called on a locked surface.</P 172 >The blit function should not be called on a locked surface.</P
173 ><DIV 173 ><P
174 CLASS="NOTE"
175 ><BLOCKQUOTE
176 CLASS="NOTE"
177 ><P
178 ><B
179 >Note: </B
180 >The results of blitting operations vary greatly depending on whether <TT 174 >The results of blitting operations vary greatly depending on whether <TT
181 CLASS="LITERAL" 175 CLASS="LITERAL"
182 >SDL_SRCAPLHA</TT 176 >SDL_SRCAPLHA</TT
183 > is set or not. See <A 177 > is set or not. See <A
184 HREF="sdlsetalpha.html" 178 HREF="sdlsetalpha.html"
185 >SDL_SetAlpha</A 179 >SDL_SetAlpha</A
186 >.</P 180 > for an explaination of how this affects your results. Colorkeying and alpha attributes also interact with surface blitting, as the following pseudo-code should hopefully explain.
187 ></BLOCKQUOTE 181 <PRE
188 ></DIV 182 CLASS="PROGRAMLISTING"
183 >if (source surface has SDL_SRCALPHA set) {
184 if (source surface has alpha channel (that is, format-&#62;Amask != 0))
185 blit using per-pixel alpha, ignoring any colour key
186 else {
187 if (source surface has SDL_SRCCOLORKEY set)
188 blit using the colour key AND the per-surface alpha value
189 else
190 blit using the per-surface alpha value
191 }
192 } else {
193 if (source surface has SDL_SRCCOLORKEY set)
194 blit using the colour key
195 else
196 ordinary opaque rectangular blit
197 }</PRE
198 ></P
189 ></DIV 199 ></DIV
190 ><DIV 200 ><DIV
191 CLASS="REFSECT1" 201 CLASS="REFSECT1"
192 ><A 202 ><A
193 NAME="AEN1835" 203 NAME="AEN1912"
194 ></A 204 ></A
195 ><H2 205 ><H2
196 >Return Value</H2 206 >Return Value</H2
197 ><P 207 ><P
198 >If the blit is successful, it returns <SPAN 208 >If the blit is successful, it returns <SPAN
224 have access to the video memory again.</P 234 have access to the video memory again.</P
225 ></DIV 235 ></DIV
226 ><DIV 236 ><DIV
227 CLASS="REFSECT1" 237 CLASS="REFSECT1"
228 ><A 238 ><A
229 NAME="AEN1843" 239 NAME="AEN1920"
230 ></A 240 ></A
231 ><H2 241 ><H2
232 >See Also</H2 242 >See Also</H2
233 ><P 243 ><P
234 ><A 244 ><A