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### #Actualjeff8j

Posted 12 May 2013 - 12:41 PM

I have old opengl1/1.5 immediate mode code im trying to get updated into opengl es 2 using glsl. I have some code that creates 2d box using glVertex3i to set the location in pixels. I have a box drawing in glsl but its in the center using

gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;

How can I set it using pixels? Im not concerned about passing the values yet just changing the gl_Position to say put it 100px from the bottom and 100px in from the left that would be a great starting point. Thanks

I figure I might be able to (havent tried) make a box that takes up the whole screen then use the frag shader to only set the pixels I want but then it would have to run over per every pixel on screen but thats got to be inefficient I would think theres a better way?

### #2jeff8j

Posted 12 May 2013 - 12:40 PM

I have old opengl1/1.5 immediate mode code im trying to get updated into opengl es 2 using glsl. I have some code that creates 2d box using glVertex3i to set the location in pixels. I have a box drawing in glsl but its in the center using

gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;

How can I set it using pixels? Im not concerned about passing the values yet just changing the gl_Position to say put it 100px from the bottom and 100px in from the left that would be a great starting point. Thanks

I figure I might be able to (havent tried) make a box that takes up the whole screen then use the frag shader to only set the pixels I want but then it would have to run over per every pixel on screen but thats got to be inefficient I would think theres a better way?

### #1jeff8j

Posted 12 May 2013 - 12:35 PM

I have old opengl1/1.5 immediate mode code im trying to get updated into opengl es 2 using glsl. I have some code that creates 2d box using glVertex3i to set the location in pixels. I have a box drawing in glsl but its in the center using

gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;

How can I set it using pixels? Im not concerned about passing the values yet just changing the gl_Position to say put it 100px from the bottom and 100px in from the left that would be a great starting point. Thanks

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