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authorMaarten Maathuis <madman2003@gmail.com>2008-07-01 16:00:09 +0200
committerMaarten Maathuis <madman2003@gmail.com>2008-07-01 16:00:09 +0200
commit2b9c5719c09226a36a4a1e9869e6075b8ec08824 (patch)
tree50b0868d30b341425dc06b5f0dc8060dbf295af2 /linux-core
parentbc32d1798a213d7701b20feb95781eb51a42e945 (diff)
NV50: switch to fixed point scale factor calculations
Diffstat (limited to 'linux-core')
-rw-r--r--linux-core/nv50_crtc.c15
1 files changed, 8 insertions, 7 deletions
diff --git a/linux-core/nv50_crtc.c b/linux-core/nv50_crtc.c
index fd2ad38a..c9745e08 100644
--- a/linux-core/nv50_crtc.c
+++ b/linux-core/nv50_crtc.c
@@ -232,17 +232,18 @@ static int nv50_crtc_set_dither(struct nv50_crtc *crtc)
static void nv50_crtc_calc_scale(struct nv50_crtc *crtc, uint32_t *outX, uint32_t *outY)
{
- float hor_scale, ver_scale;
+ uint32_t hor_scale, ver_scale;
- hor_scale = (float)crtc->native_mode->hdisplay/(float)crtc->mode->hdisplay;
- ver_scale = (float)crtc->native_mode->vdisplay/(float)crtc->mode->vdisplay;
+ /* max res is 8192, which is 2^13, which leaves 19 bits */
+ hor_scale = (crtc->native_mode->hdisplay << 19)/crtc->mode->hdisplay;
+ ver_scale = (crtc->native_mode->vdisplay << 19)/crtc->mode->vdisplay;
if (ver_scale > hor_scale) {
- *outX = crtc->mode->hdisplay * hor_scale;
- *outY = crtc->mode->vdisplay * hor_scale;
+ *outX = (crtc->mode->hdisplay * hor_scale) >> 19;
+ *outY = (crtc->mode->vdisplay * hor_scale) >> 19;
} else {
- *outX = crtc->mode->hdisplay * ver_scale;
- *outY = crtc->mode->vdisplay * ver_scale;
+ *outX = (crtc->mode->hdisplay * ver_scale) >> 19;
+ *outY = (crtc->mode->vdisplay * ver_scale) >> 19;
}
}