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| author | Hampus Wessman <hampus.wessman@sonymobile.com> | 2013-04-15 12:26:51 +0200 |
|---|---|---|
| committer | Ed Savage-Jones <edward.savage-jones@sonymobile.com> | 2017-07-27 13:44:00 +0000 |
| commit | 8673c2adc72069a25aaa99776fec7c93495daa07 (patch) | |
| tree | 3101bd35bde2cc5725554315a3053455377fcb02 | |
| parent | 9b9e823096ebee3a39e1a3e36b6c6a60f2f38d05 (diff) | |
Fix graphical artifact in the fisheye effect
The fisheye effect generates a graphical artifact close to the center of
the picture, due to bad precision and division by zero in the shader.
The problem is fixed by making a small change in the shader, so that the
picture is uniformly scaled close to the center instead. This avoids the
problem and looks as expected, without affecting the performance.
Bug: 64107054
Test: Manual - Install dev sample HelloEffects and use the 'fisheye'
from the overflow. There is a small artifact in the center of the puppy
without this patch applied. Think of the puppies!!
Change-Id: I063f60facd30708db29ff544fdb47ac896e3d54b
| -rw-r--r-- | media/mca/filterpacks/java/android/filterpacks/imageproc/FisheyeFilter.java | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/media/mca/filterpacks/java/android/filterpacks/imageproc/FisheyeFilter.java b/media/mca/filterpacks/java/android/filterpacks/imageproc/FisheyeFilter.java index 2ff65889e1ac..e0dbd571d560 100644 --- a/media/mca/filterpacks/java/android/filterpacks/imageproc/FisheyeFilter.java +++ b/media/mca/filterpacks/java/android/filterpacks/imageproc/FisheyeFilter.java @@ -49,6 +49,8 @@ public class FisheyeFilter extends Filter { private int mHeight = 0; private int mTarget = FrameFormat.TARGET_UNSPECIFIED; + // The constant min_dist, below, is an arbitrary number that gives good enough precision in + // the center of the picture without affecting the fisheye effect noticeably. private static final String mFisheyeShader = "precision mediump float;\n" + "uniform sampler2D tex_sampler_0;\n" + @@ -59,8 +61,10 @@ public class FisheyeFilter extends Filter { "varying vec2 v_texcoord;\n" + "void main() {\n" + " const float m_pi_2 = 1.570963;\n" + + " const float min_dist = 0.01;\n" + " vec2 coord = v_texcoord - vec2(0.5, 0.5);\n" + " float dist = length(coord * scale);\n" + + " dist = max(dist, min_dist);\n" + " float radian = m_pi_2 - atan(alpha * sqrt(radius2 - dist * dist), dist);\n" + " float scalar = radian * factor / dist;\n" + " vec2 new_coord = coord * scalar + vec2(0.5, 0.5);\n" + |