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  1. Replies
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    Yes. fovy is the angle between the top and bottom...

    Yes. fovy is the angle between the top and bottom edges of the view frustum (the angle between either edge and the centre is fovy/2).
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    The original was released at a time when few PCs...

    The original was released at a time when few PCs had 3D-accelerated video hardware, so I presume that you're referring to the "remastered" version which has just been released.

    A quick web search...
  3. Well, you'd probably perform the calculations...

    Well, you'd probably perform the calculations as-needed, rather than processing all vertices and faces for each smoothing group. A given face only has a single normal, a vertex has one normal for...
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    Most image formats can't handle GL_RGBA32F (BMP...

    Most image formats can't handle GL_RGBA32F (BMP certainly can't). TIFF probably can (it tries to support everything), but I doubt that much software which "supports TIFF" can handle it.

    Most...
  5. IMHO, it's better to start with legacy OpenGL...

    IMHO, it's better to start with legacy OpenGL until you have some familiarity with the basic concepts, then switch.

    If you try to use modern OpenGL from the outset, you have to learn several...
  6. Aside from the buffer-management issues, you can...

    Aside from the buffer-management issues, you can halve the memory usage by using 16-bit fixed-point values instead of 32-bit floats.

    Another possibility for drawing axis-aligned rectangles is to...
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    Pango includes functions to render the layouts it...

    Pango includes functions to render the layouts it creates, using Win32, FreeType, Xft, CoreText, or cairo.
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    In the general case, use Pango or native OS...

    In the general case, use Pango or native OS functions to render complete strings into a bitmap which is then uploaded to a texture.

    The glCallLists() approach can only work with "linear" scripts,...
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    IOW, you want a larger view angle. It takes...

    IOW, you want a larger view angle.


    It takes an aspect ratio and a view angle.


    glViewport() sets the portion of the window which is mapped to X and Y coordinates of the clip space. Enlarging...
  10. Thread: hole filling

    by GClements
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    No. OpenGL is a rendering API, not a...

    No.

    OpenGL is a rendering API, not a modelling/geometry library.
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    If you look at the sample code, the condition...

    If you look at the sample code, the condition expression is uniform (i.e. involves only uniforms and constants), so the value will be the same for all fragments within a group. Modern hardware will...
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    My first guess would be issues related to the...

    My first guess would be issues related to the precision of the trigonometric functions.

    You could try reformulating your equations to avoid some of these. A brief look at your code shows that most...
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    You aren't going to see implementations duplicate...

    You aren't going to see implementations duplicate large amounts of "stable" data, particularly in VRAM.

    What can realistically happen is that updating data may result in both the old and new...
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    No. You're assuming that the contours are...

    No.


    You're assuming that the contours are convex, but there's no reason to believe that assumption is valid.
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    Conceptually, a context is effectively a (large)...

    Conceptually, a context is effectively a (large) "struct"; see the state tables in the final chapter of the specification for what it contains. However, some of the fields are "handles" to "objects"...
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    Chapter 5 of the OpenGL 4.5 compatibility profile...

    Chapter 5 of the OpenGL 4.5 compatibility profile specification says



    The core profile specification omits display lists (which don't exist in the core profile), but is otherwise identical.
    ...
  17. Smoothing groups are an alternative to providing...

    Smoothing groups are an alternative to providing explicit vertex normals. If a polygon's vertices include normal references, those supersede any smoothing group.

    Generating vertex normals usually...
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    What's the problem, exactly? One thing which I...

    What's the problem, exactly?

    One thing which I notice is that the middle triangle (v0,v1,v2) has the opposite direction to the parent and to the other three, i.e. if (a,b,c) is counter-clockwise,...
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    You need to use a topological sort...

    You need to use a topological sort.

    You can't use std::sort (or qsort() etc) because (in general) there isn't a total ordering. To make matters worse, the graph may well have cycles, in which case...
  20. Yes. Probably.

    Yes.


    Probably.
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    Given the memory and bandwidth issues of this...

    Given the memory and bandwidth issues of this particular application, I'd consider using YCbCr (or similar) for (amortised) 12-bpp (i.e. one 8-bit luma texture at 1920x1080 and 2x 8-bit chroma...
  22. Assuming that you want to do this without using...

    Assuming that you want to do this without using shaders, my first attempt would be to try to re-purpose the OpenGL lighting calculations. Place a light source at the viewpoint, so the diffuse...
  23. Khronos develops specifications, not software. ...

    Khronos develops specifications, not software.

    In any case, an "OpenGL IDE" is a dumb idea. Software which uses OpenGL isn't fundamentally different from software which doesn't. A developer's...
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    As Cornix says, avoid glBegin/glEnd, use...

    As Cornix says, avoid glBegin/glEnd, use glDrawArrays() with a vertex buffer. Using a vertex buffer means that you only need to transfer data from system memory to video memory once, as it comes in,...
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    Several options spring to mind: Draw a...

    Several options spring to mind:


    Draw a screen-sized quad with a fragment shader which tests gl_FragCoord.
    Draw full-height vertical lines every 3.258 pixels in the X direction, and...
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