arrays - Is the glVertexAttribPointer state bound to the current GL_ARRAY_BUFFER? -


i have simple question. right, glvertexattribpointer operations have called once gl_array_buffer save attribute states until want change them? or need call glvertexattribpointer each time in between glbindbuffer(gl_array_buffer, ...); , gldrawarrays(...); ?

is right, glvertexattribpointer operations have called once gl_array_buffer save attribute states until want change them? or need call glvertexattribpointer each time.

glvertexattribpointer specifies location , data format of array of generic vertex attribute @ specified index.

this has done before object drawn:

glbindbuffer( array_buffer, posbufobj ); glenablevertexattribarray( 0 ); glvertexattribpointer( 0, .... ); glbindbuffer( nvbufobj ); glenablevertexattribarray( 1 ); glvertexattribpointer( 1, .... );  gldrawarrays( .... ) gldisablevertexattribarray( 0 ); gldisablevertexattribarray( 1 ); glbindbuffer( array_buffer, 0 );

yes, sufficient call glvertexattribpointer once per vetrex attribute. vertex specification keept until not redefined. of course, buffer object, glvertexattribpointer refers must not deleted. state, whether vertex attribute enabled (glenablevertexattribarray) or not kept until vertex attribute disabled again (gldisablevertexattribarray).
khronos opengl wiki vertex specification says:

the glvertexattribpointer functions state attribute index gets array data from.

this state can retrieved glgetvertexattrib.

more information vertex attrbutes can found in opengl coreprofile specification chapter 10.2 10.6

to handle different vertex attribute pointers , not specify , enable or disable them alternately, vertex array object can generated (glgenvertexarrays), stores information buffer location, data format, state , attribute index:

generated , specify vertex array object

vaoobj = glgenvertexarrays(); glbindvertexarray( vaoobj ); glbindbuffer( array_buffer, posbufobj ); glenablevertexattribarray( 0 ); glvertexattribpointer( 0, .... ); glbindbuffer( nvbufobj ); glenablevertexattribarray( 1 ); glvertexattribpointer( 1, .... ); glbindbuffer(gl_array_buffer, 0); glbindvertexarray( 0 );

bind vertex array object

glbindvertexarray( vaoobj ); gldrawarrays( .... ) glbindvertexarray( 0 );

Comments

Post a Comment

Popular posts from this blog

Is there a better way to structure post methods in Class Based Views -

i'm using class based views in django , never specify url in ajax calls , omit action parameter in form because know these requests go through post method of class based view. notice view - profile page make many requests depending on user updating on page - post method become convoluted , if/else mess example: def post(self, request, *args, **kwargs): # handle user changing available date if request.post.get('availabledate') != none: self.updateavailabledate(request) return jsonresponse({'result':'success'}) if request.post.get('newprojectname') != none: creative_user = creativeuserprofile.objects.get(id = request.user.id) project = project.create_project(creative_user, request.post['newprojectname']) project.save() return jsonresponse({'projectid': project.id }) if request.post.get('projectimage') != none , request.files['file']: proj...
Read more

performance - Why is XCHG reg, reg a 3 micro-op instruction on modern Intel architectures? -

i'm doing micro-optimization on performance critical part of code , came across sequence of instructions (in at&t syntax): add %rax, %rbx mov %rdx, %rax mov %rbx, %rdx i thought had use case xchg allow me shave instruction , write: add %rbx, %rax xchg %rax, %rdx however, dimay found agner fog's instruction tables , xchg 3 micro-op instruction 2 cycle latency on sandy bridge, ivy bridge, broadwell, haswell , skylake. 3 whole micro-ops , 2 cycles of latency! 3 micro-ops throws off 4-1-1-1 cadence , 2 cycle latency makes worse original in best case since last 2 instructions in original might execute in parallel. now... cpu might breaking instruction micro-ops equivalent to: mov %rax, %tmp mov %rdx, %rax mov %tmp, %rdx where tmp anonymous internal register , suppose last 2 micro-ops run in parallel latency 2 cycles. given register renaming occurs on these micro-architectures, though, doesn't make sense me done way. why wouldn't register renamer ...
Read more

c# - Asp.net web api : redirect unauthorized requst to forbidden page -

im trying redirect unauthorized request forbidden page instead i'm getting forbidden page in response body , how can fix ? here's startup class : app.createperowincontext(storecontext.create); app.createperowincontext<applicationusermanager>(applicationusermanager.create); app.createperowincontext<applicationsigninmanager>(applicationsigninmanager.create); app.usecookieauthentication(new cookieauthenticationoptions { authenticationtype = defaultauthenticationtypes.applicationcookie, expiretimespan = timespan.fromdays(30), }); app.useexternalsignincookie(defaultauthenticationtypes.externalcookie); app.usetwofactorsignincookie(defaultauthenticationtypes.twofactorcookie, timespan.fromminutes(5)); app.usetwofactorrememberbrowsercookie(defaultauthenticationtypes.twofactorrememberbrowsercookie); the method im trying reach : [httpget] [authorize(roles = "admin")] public string getcurrentusername() { return userman...
Read more