Bug 51421

Summary: sin and cos is broken
Product: Mesa Reporter: Christopher Egert <cme3000>
Component: Drivers/Gallium/i915gAssignee: Default DRI bug account <dri-devel>
Status: RESOLVED NOTABUG QA Contact:
Severity: normal    
Priority: medium    
Version: git   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: i915 features:

Description Christopher Egert 2012-06-25 13:00:11 UTC 
sin is broken with negative values
it just renders on the right side of the screen in shaders like 
http://glsl.heroku.com/e#2465.1

cos seems to be broken, too, just replace sin with cos on that web page.

mesa: git-d105654
OS: Debian unstable, kernel 3.4
Comment 1 Golubev Yaroslav 2012-11-27 11:26:26 UTC 
http://glsl.heroku.com/e#2465.1
>#ifdef GL_ES
>precision mediump float;
>#endif
>uniform float time;
>uniform vec2 mouse;
>uniform vec2 resolution;
>
>void main( void ) {
>	float bla = gl_FragCoord.x/resolution.x; 
>	float value = sin((bla-0.5)*100.0);
>	gl_FragColor = vec4(value,value,value, 1.0 );
>}

1) according to specification sin accepts angle in radians:
2) also gl_FragColor.# should be in [0;1], but sin (x in (0;-pi))<0

=> float value = abs(sin(radians((bla-0.5)*100.0)));
works fine

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