Added SDL_modf() and SDL_modff()

This function is useful for accumulating relative mouse motion if you want to only handle whole pixel movement.
e.g.
static float dx_frac, dy_frac;
float dx, dy;

/* Accumulate new motion with previous sub-pixel motion */
dx = event.motion.xrel + dx_frac;
dy = event.motion.yrel + dy_frac;

/* Split the integral and fractional motion, dx and dy will contain whole pixel deltas */
dx_frac = SDL_modff(dx, &dx);
dy_frac = SDL_modff(dy, &dy);
if (dx != 0.0f || dy != 0.0f) {
    ...
}
This commit is contained in:
Sam Lantinga
2022-12-29 21:39:08 -08:00
parent ead4f122e4
commit 7f23d71b6a
20 changed files with 149 additions and 7 deletions

View File

@@ -546,6 +546,7 @@
<ClCompile Include="..\..\src\libm\s_cos.c" />
<ClCompile Include="..\..\src\libm\s_fabs.c" />
<ClCompile Include="..\..\src\libm\s_floor.c" />
<ClCompile Include="..\..\src\libm\s_modf.c" />
<ClCompile Include="..\..\src\libm\s_scalbn.c" />
<ClCompile Include="..\..\src\libm\s_sin.c" />
<ClCompile Include="..\..\src\libm\s_tan.c" />

View File

@@ -964,6 +964,9 @@
<ClCompile Include="..\..\src\libm\s_floor.c">
<Filter>libm</Filter>
</ClCompile>
<ClCompile Include="..\..\src\libm\s_modf.c">
<Filter>libm</Filter>
</ClCompile>
<ClCompile Include="..\..\src\libm\s_scalbn.c">
<Filter>libm</Filter>
</ClCompile>