use the patch with dub - easier to understand the draw types when you use TRIANGLE_STRIP instead of Strip there is no difference between TRIANGLES draw. Where is Strip defined couldn´t find it - saw it someday have a look at the patch matthias
yep, thanks, the drawing mode you send to the primitive is not the openGL drawing mode. you can have a look at src/base/GemShape.cpp :
void GemShape :: typeMess(t_symbol *type) { char c=toupper(*type->s_name); switch (c){ case 'D': // default m_drawType = GL_DEFAULT_GEM; break; case 'L': // line m_drawType = GL_LINE_LOOP; break; case 'F': // fill m_drawType = GL_POLYGON; break; case 'Q': // quads m_drawType = GL_QUADS; break; case 'P': // point m_drawType = GL_POINTS; break; case 'T': // triangles m_drawType = GL_TRIANGLES; break; case 'S': // strip m_drawType = GL_TRIANGLE_STRIP; break; default: error ("unknown draw style"); return; } setModified(); }
so sending [draw foo( to the square will draw the square with GL_POLYGON... sending draw QUAD_STRIP will draw the square with GL_QUADS. sending draw Line / line_loop / LINE_STRIP will use gl_line_loop draw TRIANGLE_STRIP will use gl_triangle, you have to send draw strip in order to have triangle strip. etc.
ah now i got it send draw Trip and you get Triangles, draw Soap for Strip it just use the initial letter
but then LINE_STRIP, LINES, QUAD_STRIP and TRIANGLE_FAN are not available maybe not necessary in this context
so the drawing mode and there comments in my initial patch was right. changing them result in unexpected behaviour.
But your patch clearly point that the drawing time of a primitive is important. If i understand correctly, i would say that the driver automatically quad primitive into primitive that use triangle, since there is less geometry_intype than drawing mode.
the geometry_shader can´t use quads, they will cut into triangles and the object has to be drawn with them when you use square as geom with only 4 vertices the plane can´t be filled, drawn as triangle will output an triangle half quad and drawn as strip connect v0 v1 v2 and v1 v2 v3 looks like this
mesh_square will provide a simple filled square in strip mode drawn
Matthias
Cyrille
