HP j6700 OpenGL Implementation Guide for HP-UX 11.x - Page 58

texture downloading performance, selection performance, GL_TEXTURE_GEN

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programming hints OpenGL performance hints glNormal3fv(&v2); glVertex3fv(&p5); glNormal3fv(&v2); glVertex3fv(&p6); ... glEnd(); The reason this is faster is the display list can optimize this type of primitive into a single, very efficient structure. The small cost of adding extra data is offset by this optimization. Performance is increased by maximizing the number of vertices per Begin/End pair. If your vertex data in memory is organized in a linear, rather than a random manner, performance is enhanced by taking advantage of vertex pre-fetch. It is most efficient to use 32-bit float data, which avoids the need to convert data. texture downloading performance This section includes some helpful hints for improving the performance of your program when downloading textures. • If you are downloading MIP maps, always begin with the base level (level 0) first. • If it is possible, you should use texture objects to store and bind textures. • If you are doing dynamic downloading of texture maps, you will get better performance by replacing the current texture with a texture of the same width, height, border size, and format. This should be done instead of deleting the old texture and creating a new one. selection performance To increase the performance of selection (glRenderMode GL_SELECTION) it is recommended that the following capabilities be disabled before entering the selection mode. GL_TEXTURE_* GL_TEXTURE_GEN_* GL_FOG GL_LIGHTING 56 Chapter 5

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programming hints
OpenGL performance hints
Chapter 5
56
glNormal3fv(&v2); glVertex3fv(&p5);
glNormal3fv(&v2); glVertex3fv(&p6);
...
glEnd();
The reason this is faster is the display list can optimize this type of
primitive into a single, very efficient structure. The small cost of adding
extra data is offset by this optimization.
Performance is increased by maximizing the number of vertices per
Begin/End pair. If your vertex data in memory is organized in a linear,
rather than a random manner, performance is enhanced by taking
advantage of vertex pre-fetch. It is most efficient to use 32-bit float data,
which avoids the need to convert data.
texture downloading performance
This section includes some helpful hints for improving the performance
of your program when downloading textures.
•
If you are downloading MIP maps, always begin with the base level
(level 0) first.
•
If it is possible, you should use texture objects to store and bind
textures.
•
If you are doing dynamic downloading of texture maps, you will get
better performance by replacing the current texture with a texture of
the same width, height, border size, and format. This should be done
instead of deleting the old texture and creating a new one.
selection performance
To increase the performance of selection (
glRenderMode GL_SELECTION
)
it is recommended that the following capabilities be disabled before
entering the selection mode.
GL_TEXTURE_*
GL_TEXTURE_GEN_*
GL_FOG
GL_LIGHTING