A surprising number of apps and benchmarks have poor code like this:
glBegin(GL_LINE_STRIP);
glVertex(v1);
glVertex(v2);
glEnd();
// Possibly some no-op state changes here
glBegin(GL_LINE_STRIP);
glVertex(v3);
glVertex(v4);
glEnd();
// repeat many, many times.
The above sequence can be converted into:
glBegin(GL_LINES);
glVertex(v1);
glVertex(v2);
glVertex(v3);
glVertex(v4);
glEnd();
Similarly for GL_POINTS, GL_TRIANGLES, etc.
Merging was already implemented for GL_QUADS in the display list code.
Now other prim types are handled and it's also done for immediate mode.
In one case:
before after
-----------------------------------------------
number of st_draw_vbo() calls: 141 45
number of _mesa_prims issued: 7520 632
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: José Fonseca <jfonseca@vmware.com>
Brian Paul
4ea05bcba6