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Re: [Public WebGL] ESSL 3.5 Comments Compliance



shaderSource isn't supposed to do anything, though. That would be a
big behavioral change and trip people up when they are trying to write
error handling/etc.
"The source code strings are not scanned or parsed at this time; they
are simply copied into the specified shader object."

--
Ben Vanik
http://www.noxa.org



2011/1/15 Mo, Zhenyao <zhenyao@gmail.com>:
>
> I believe the validation also has to happen above ANGLE translator, as
> we should raise an error in shaderSource(), whereas ANGLE translator
> is only called in compileShader().
>
> 2011/1/14 Kenneth Russell <kbr@google.com>:
>>
>> On Fri, Jan 14, 2011 at 7:04 PM, Vladimir Vukicevic
>> <vladimir@mozilla.com> wrote:
>>>
>>>
>>> ----- Original Message -----
>>>> On Thu, Jan 13, 2011 at 5:35 PM, Kenneth Russell <kbr@google.com>
>>>> wrote:
>>>> > I agree with you. With a little preprocessing at the browser layer
>>>> > before handing down a const char* to the OpenGL layer (be it the
>>>> > ANGLE
>>>> > shader translator or OpenGL directly), a WebGL implementation should
>>>> > be able to allow the entire Unicode character range to be used in
>>>> > comments by stripping them completely. I don't think we need to
>>>> > reference UTF-8, since DOMStrings come in in (not necessarily valid)
>>>> > UTF-16. See http://dev.w3.org/2006/webapi/WebIDL/#idl-DOMString .
>>>> >
>>>> > Can you either propose some spec text or just edit the spec
>>>> > directly?
>>>>
>>>> I've gone ahead and updated the WebGL spec to require that the full
>>>> Unicode character set can be used in comments in shaders, and updated
>>>> the glsl-conformance.html test to ensure both this and that non-ASCII
>>>> characters in the actual shader text is rejected. Please send any
>>>> comments to the list.
>>>
>>> Sounds great to me -- Ken, is the plan to have ANGLE just strip comments and verify that the remainder is ASCII (or the limited subset thereof)?  Or would we have to do that at a level before the shader translator?
>>
>> I believe the removal of comments must be done at a level above the
>> shader translator. The browser takes in DOMStrings containing
>> potentially invalid UTF-16 data, and before the conversion to either
>> ASCII or UTF-8 it needs to strip the comments potentially containing
>> non-ASCII characters. We should modify ANGLE to enforce that the
>> incoming const char* is not only ASCII but also fully ESSL compliant,
>> though in the WebKit implementation that is currently being done at
>> the browser level.
>>
>> I'm about to upload a patch for
>> https://bugs.webkit.org/show_bug.cgi?id=52390 implementing the removal
>> of comments. The WebGL conformance suite has already been updated for
>> the new rules.
>>
>> -Ken
>>
>>>    - Vlad
>>>
>>>> > On Thu, Jan 13, 2011 at 4:49 PM, Gregg Tavares (wrk)
>>>> > <gman@google.com> wrote:
>>>> >> I really want to emphasize that it would be really insensitive to
>>>> >> make WebGL
>>>> >> only support ASCII in comments in shaders. It's called WebGL
>>>> >> because it's on
>>>> >> the WEB and the WEB is not ASCII. I know the OpenGL spec says
>>>> >> ASCII. I have
>>>> >> a feeling though few if any drivers enforce that and like I
>>>> >> mentioned
>>>> >> before, even if they do enforce it WebGL implementations can work
>>>> >> around it
>>>> >> by stripping the comments.
>>>> >> Imagine someone told you couldn't document your code in a language
>>>> >> you
>>>> >> understand. How would you feel? Imagine if you couldn't even write
>>>> >> a blog
>>>> >> post that showed sample code with inline comments or that if you
>>>> >> put inline
>>>> >> comments in users trying to copy and paste snippets from your
>>>> >> tutorial had
>>>> >> to manually remove all the inline comments.
>>>> >> Seriously, it seems morally wrong in 2011 to force programmers the
>>>> >> world
>>>> >> over to ASCII only for their shader comments.
>>>> >> Here's a shader from this page
>>>> >> WebGL MQO Loader
>>>> >> Are we really going to tell that guy he has to learn English if he
>>>> >> wants to
>>>> >> document his code?
>>>> >> I think we should diverge from the OpenGL ES spec here in the
>>>> >> interest of
>>>> >> the needs of the Web and the world at large. Checking for valid
>>>> >> UTF8 is easy
>>>> >> if we want to validate input and workarounds past that are probably
>>>> >> not
>>>> >> needed and even if they are probably very easy. The ANGLE
>>>> >> translator already
>>>> >> strips comments as far as I know so just validating UTF8 and
>>>> >> calling the
>>>> >> translator is enough to allow WebGL to be an international
>>>> >> developer
>>>> >> friendly standard.
>>>> >>
>>>> >> ---------------------------
>>>> >> #ifdef GL_ES
>>>> >> precision highp float;
>>>> >> #endif
>>>> >> //VertexShader
>>>> >> //入力パラメータ
>>>> >> attribute vec3 aVertexPosition; //入力位置
>>>> >> attribute vec3 aVertexNormal; //入力法線
>>>> >> attribute vec3 aVertexTangent; //入力法線
>>>> >> attribute vec3 aVertexBinormal; //入力法線
>>>> >> attribute vec4 aVertexColor; //入力カラー
>>>> >> attribute vec2 aTextureCoord; //入力UV
>>>> >> //出力パラメータ
>>>> >> varying vec4 vColor; //出力カラー
>>>> >> varying vec2 vTextureCoord; //出力UV
>>>> >> varying vec3 vNormal; //出力法線
>>>> >> varying vec3 vTangent; //出力接線
>>>> >> varying vec3 vBinormal; //出力従法線
>>>> >> varying vec3 vLightDir; //出力ライト
>>>> >> varying vec3 vEyeDir; //出力視線
>>>> >> varying vec4 vShadowMap; //出力シャドウマップ位置
>>>> >> //固定パラメータ
>>>> >> uniform mat4 WorldMatrix; //ワールドマトリクス
>>>> >> uniform mat4 ViewMatrix; //ビューマトリクス
>>>> >> uniform mat4 ProjMatrix; //プロジェクションマトリクス
>>>> >> uniform mat4 SMapLightMatrix; //シャドウマップライトマトリクス
>>>> >> //
>>>> >> uniform bool use_dif_texture; //ディフューズテクスチャ使用
>>>> >> uniform bool use_alpha_texture; //アルファテクスチャ使用
>>>> >> uniform bool use_celsdif_texture; //ディフューズセルシェーダテクスチャ使用
>>>> >> uniform bool use_celsspc_texture; //スペキュラセルシェーダテクスチャ使用
>>>> >> uniform bool use_reflec_texture; //リフレクションテクスチャ使用
>>>> >> uniform bool use_bump_texture; //バンプテクスチャ使用
>>>> >> uniform bool use_smap_texture; //シャドウマップテクスチャ使用
>>>> >> uniform bool use_light; //ライティング使用
>>>> >> uniform bool use_edge; //エッジ使用
>>>> >> uniform bool draw_smap_flg; //シャドウマップ描画
>>>> >> //
>>>> >> uniform vec3 light_dir; //ライト方向
>>>> >> uniform vec3 g_ViewDir; //エッジ色
>>>> >> uniform float edge_scale; //エッジスケール
>>>> >> mat3 transpose_mat3(mat3 mt){
>>>> >> mat3 mt2;
>>>> >> mt2[0][0]=mt[0][0];
>>>> >> mt2[0][1]=mt[1][0];
>>>> >> mt2[0][2]=mt[2][0];
>>>> >> mt2[1][0]=mt[0][1];
>>>> >> mt2[1][1]=mt[1][1];
>>>> >> mt2[1][2]=mt[2][1];
>>>> >> mt2[2][0]=mt[0][2];
>>>> >> mt2[2][1]=mt[1][2];
>>>> >> mt2[2][2]=mt[2][2];
>>>> >> return mt2;
>>>> >> }
>>>> >> void main(void) {
>>>> >> vec3 now_pos=aVertexPosition;
>>>> >> if(use_edge){
>>>> >> now_pos+=(aVertexNormal*edge_scale);
>>>> >> }
>>>> >> mat4 WorldMatrixView=ViewMatrix * WorldMatrix;
>>>> >> vec3 dpos2 =(WorldMatrixView * vec4(now_pos,1.0)).xyz;
>>>> >> gl_Position = ProjMatrix * vec4(dpos2,1.0);
>>>> >> if(use_dif_texture || use_alpha_texture || use_bump_texture){
>>>> >> vTextureCoord = aTextureCoord;
>>>> >> }else{
>>>> >> vTextureCoord = vec2(0.0,0.0);
>>>> >> }
>>>> >> if(draw_smap_flg){
>>>> >> vShadowMap=vec4(gl_Position);
>>>> >> }else{
>>>> >> if(use_smap_texture){
>>>> >> vShadowMap=SMapLightMatrix * vec4(dpos2,1.0);
>>>> >> }
>>>> >> }
>>>> >> //
>>>> >> vColor = aVertexColor;
>>>> >> //
>>>> >> mat3 nmt=mat3(WorldMatrix);
>>>> >> vec3 norm=normalize(nmt*aVertexNormal);
>>>> >> vNormal=norm;
>>>> >> //
>>>> >> if(use_bump_texture){
>>>> >> vec3 tangent=normalize(nmt*aVertexTangent);
>>>> >> vec3 binorm =normalize(nmt*aVertexBinormal);
>>>> >> mat3 tan_mt=mat3(tangent,binorm,norm);
>>>> >> // tan_mt=transpose(tan_mt);
>>>> >> tan_mt=transpose_mat3(tan_mt);
>>>> >> vTangent =tangent;
>>>> >> vBinormal=binorm;
>>>> >> vLightDir=tan_mt*light_dir;
>>>> >> vEyeDir =tan_mt*g_ViewDir;
>>>> >> }else{
>>>> >> vLightDir=light_dir;
>>>> >> vEyeDir =g_ViewDir;
>>>> >> }
>>>> >> }
>>>> >>
>>>> >
>>>
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