c - Is it possible to copy data from a texture 2D (GL_TEXTURE_2D) to an array buffer (GL_ARRAY_BUFFER)? -


i developing program, can calculate histogram on gpu. i'm using opengl write code. in first step, load value of pixel (rgb) array (arr_image) , upload vertex buffer (vbo):

gluint vbo; glgenbuffers(1, &vbo); glbindbuffer(gl_array_buffer, vbo);  gluint num_input_data = width * height;  /* upload data */ glbufferdata(gl_array_buffer, num_input_data * sizeof(float) * 3, arr_image, gl_static_draw);

and it's working, can calculate histogram of image.

but now, want load data texture (gl_texture_2d) (as results of previous steps) array buffer (gl_array_buffer). possible?

i'm not sure if overall approach best way go, i'm going address specific question here:

a buffer object in opengl can bound every buffer target. copy pixel data texture buffer object, can bind buffer gl_pixel_pack_buffer means using pixel buffer object (pbo). when pbo bound, operation reading pixel data gl write data pbo. can issue glgetteximage call. vbos, pixels pointer of these calls interpreted not client memory address, offset pbo.

you can bind buffer gl_array_buffer target , use source vertex data.


Comments

Post a Comment

Popular posts from this blog

inversion of control - Autofac named registration constructor injection -

does autofac support specifying registration name in components' constructors? example: ninject's namedattribute . you need use autofac.extras.attributed package on top achieve this so let's have 1 interface , 2 classes: public interface ihello { string sayhello(); } public class englishhello : ihello { public string sayhello() { return "hello"; } } public class frenchhello : ihello { public string sayhello() { return "bonjour"; } } then have consumer class, in want select instance injected: public class helloconsumer { private readonly ihello helloservice; public helloconsumer([withkey("en")] ihello helloservice) { if (helloservice == null) { throw new argumentnullexception("helloservice"); } this.helloservice = helloservice; } public string sayhello() { return this.helloservice.sayhello()...
Read more

verilog - Systemverilog dynamic casting issues -

i've code snippet following in testbench function void write_to_port( my_data_type_base data ); my_data_type_extended data_ext; if(!$cast(data_ext, data)); `uvm_error(get_type_name(), "failed cast"); `uvm_info(get_name(), $psprintf("data_ext :\n%s", data_ext.sprint()), uvm_medium) // write data_ext out port.... endfunction when run it, i'm getting uvm_error "failed cast." i'm not quire sure why $cast not returning 1. can see, i'm printing out extended class data item after casting uvm_info. can see it's being cast properly. if don't use $cast if condition, don't runtime error. isn't coding practice use if dynamic cast check if $cast returning 1 ? what might reason behind cast not returning 1 in above case? i think semicolon on line 'if' not belong? i think consumes if statement, , uvm_error executes regardless of how if evaluates: if(!$cast(data_ext, data)); <- no semico...
Read more

ios - Change Storyboard View using Seague -

i have following code checks connection server, , depending on want change views if no connection found. nsstring *connect = [nsstring stringwithcontentsofurl:[nsurl urlwithstring:@"http://myserver.com"] encoding:nsutf8stringencoding error:nil]; if (connect == null) { [self performseguewithidentifier:@"network_failure" sender:self]; } else { // other code here } my problem not change views. have added storyboard segue between 2 views identifier of network_failure . not have navigation controller or that, problem? thanks help! no not problem. first of all, in objectivec exists nil object oriented null . must use that. so: if(connect == nil) or better: if(!connect) so due fact nil not same of null , probably code does't enter in if scope . you have been able discover breakpoint. anyway: be sure set trigger segue (line) 2 view controller , , name network_failure (that not best name. should instead view1toview2 ) as, m...
Read more