When I try and display text with the GLWindowsBitmapFont in Linux, I just get white filled boxes instead of text (Master branch, May 28, 2020 ). This is illustrated by trying to run the /Samples/Lazarus/interface/winfont example.
Last edit: Chemistza 2021-07-17
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Hmm, I use GLscene successfully with Lazarus on Linux for 15 years now.
This problem affect every texture, not only BitmapFont, it appear progressively this last years, affecting some driver but working with other. It not work at all since Mesa 20.0.
Recently I find the culprit: the progressive implementation of the extension GL_EXT_direct_state_access in the Linux OpenGL drivers.
To bypass the problem and make the GLScene texture to work normally it is sufficient to disable the detection of this extension.
In OpenGLAdapter.pas, at line 3998, put "EXT_direct_state_access := CheckExtension('EXT_direct_state_access');" within a {$ifdef mswindows}
Unfortunately my knowledge of OpenGL is not sufficient to find a real solution, but for now I can live with this trick.
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Hi Patrick,
I've added ifdef in OpenGLAdapter for Linux, thank you very much. Do you use the GLScene in your Windows astronomical soft too? If yes, then lets create Grid Model of Galaxy to Solve Fermi Paradox, based on GLS and the last DR4 Gaia data.
Pavel
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Hi Pavel,
Thank you to apply the change!
I use GLScene only for the Virtual Moon Atlas software and I am very happy I can continue to provide both Windows and Linux packages.
My other software like Skychart or CCDciel use only basic bitmap display to make them more easy to run on screenless computer attached at the telescope.
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Ok Patrick,
you know we have advdemos like https://sourceforge.net/p/glscene/code/HEAD/tree/trunk/AdvDemos/Earth/ or https://sourceforge.net/p/glscene/code/HEAD/tree/branches/Examples/Astronomy/StarPlanets/Data/Constellations/ with TGLSkyDome. But there are constellations represent only in the form of central lines, while it would also be necessary to show all 88 constellations with their borders in the form of polygons. So that we can then display textures with translucent figures inside polygons or paint constellations in different colors, mainly according to the largest number of stars on the Harvard scale. Probably in Virtual Moon or in Skychat there is a display of the boundaries of constellations by polylines, but if you have a procedure for drawing polygons of constellations using Delphi with GLScene, then, please, share the code or give a link.
Regards Pavel
Last edit: Pavel Vassiliev 2022-11-21
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When I try and display text with the GLWindowsBitmapFont in Linux, I just get white filled boxes instead of text (Master branch, May 28, 2020 ). This is illustrated by trying to run the /Samples/Lazarus/interface/winfont example.
Last edit: Chemistza 2021-07-17
Hi, it's for windows only. Sorry
Hmm, I use GLscene successfully with Lazarus on Linux for 15 years now.
This problem affect every texture, not only BitmapFont, it appear progressively this last years, affecting some driver but working with other. It not work at all since Mesa 20.0.
Recently I find the culprit: the progressive implementation of the extension GL_EXT_direct_state_access in the Linux OpenGL drivers.
To bypass the problem and make the GLScene texture to work normally it is sufficient to disable the detection of this extension.
In OpenGLAdapter.pas, at line 3998, put "EXT_direct_state_access := CheckExtension('EXT_direct_state_access');" within a {$ifdef mswindows}
Unfortunately my knowledge of OpenGL is not sufficient to find a real solution, but for now I can live with this trick.
Hi Patrick,
I've added ifdef in OpenGLAdapter for Linux, thank you very much. Do you use the GLScene in your Windows astronomical soft too? If yes, then lets create Grid Model of Galaxy to Solve Fermi Paradox, based on GLS and the last DR4 Gaia data.
Pavel
Hi Pavel,
Thank you to apply the change!
I use GLScene only for the Virtual Moon Atlas software and I am very happy I can continue to provide both Windows and Linux packages.
My other software like Skychart or CCDciel use only basic bitmap display to make them more easy to run on screenless computer attached at the telescope.
Ok Patrick,
you know we have advdemos like https://sourceforge.net/p/glscene/code/HEAD/tree/trunk/AdvDemos/Earth/ or https://sourceforge.net/p/glscene/code/HEAD/tree/branches/Examples/Astronomy/StarPlanets/Data/Constellations/ with TGLSkyDome. But there are constellations represent only in the form of central lines, while it would also be necessary to show all 88 constellations with their borders in the form of polygons. So that we can then display textures with translucent figures inside polygons or paint constellations in different colors, mainly according to the largest number of stars on the Harvard scale. Probably in Virtual Moon or in Skychat there is a display of the boundaries of constellations by polylines, but if you have a procedure for drawing polygons of constellations using Delphi with GLScene, then, please, share the code or give a link.
Regards Pavel
Last edit: Pavel Vassiliev 2022-11-21