Color issues when using LineSegs and GeomPoints

[JayQc]

Hi,

Adding a LineSegs in a scene that has a GeomPoints in it seems to switch the color format on the GeomPoints from RGBA to BGRA. I’m using Panda1.10.14, here’s some code to reproduce the issue, is this a bug or am I doing something wrong?

#include "pandaFramework.h"
#include "pandaSystem.h"
#include "load_prc_file.h"
#include "geomPoints.h"
#include "lineSegs.h"

int main()
{
	load_prc_file_data( "", "load-display pandagl\n\
								win-origin -2 -2\n\
								win-size 800 600\n\
								fullscreen #f\n\
								framebuffer-hardware #t\n\
								framebuffer-software #f\n\
								depth-bits 1\n\
								color-bits 1 1 1\n\
								alpha-bits 0\n\
								stencil-bits 0\n\
								multisamples 0\n\
								notify-level warning\n\
								default-directnotify-level warning" );

	PandaFramework framework;
	framework.open_framework();

	framework.set_window_title( "Dis be where I test panda" );
	PT(WindowFramework) window = framework.open_window();
	window->setup_trackball();
	window->enable_keyboard();
	PT(GeomVertexData) vData;
	vData = new GeomVertexData("data", GeomVertexFormat::get_v3c4(), Geom::UH_static);
	PT(GeomNode) geomNode = new GeomNode("RGB points");
	GeomVertexWriter vertexWriter(vData, "vertex");
	GeomVertexWriter colorWriter(vData, "color");
	vertexWriter.add_data3(0, 0, 0);
	colorWriter.add_data4(1.f, 0.f, 0.f, 1.f);
	vertexWriter.add_data3(1.f, 0, 0);
	colorWriter.add_data4(0.f, 1.f, 0.f, 1.f);
	vertexWriter.add_data3(2.f, 0, 0);
	colorWriter.add_data4(0.f, 0.f, 1.f, 1.f);

	PT(Geom) geom = new Geom(vData);
	PT(GeomPoints) prim = new GeomPoints(Geom::UH_static);
	prim->add_vertices(0,1,2);
	geom->add_primitive(prim);
	geomNode->add_geom(geom);

	auto pointsNP = window->get_render().attach_new_node(geomNode);

//Adding the following LineSegs makes the order of the points from left to right Blue Green Red instead of Red Green Blue
	LColor color(1, 1, 1, 1);
	LineSegs lines;
	lines.set_color(color);
	
	lines.move_to(LPoint3(0, 0, 1));
	lines.draw_to(LPoint3(1,0,1));
	lines.draw_to(LPoint3(2,0,1));
	
	PT(GeomNode) lineNode = lines.create();
	window->get_render().attach_new_node(lineNode);

	framework.main_loop();
	framework.close_framework();
}

EDIT:
I was kind of in a rush when making the post, I forgot to post screenshot of the scene with/without the LineSegs.

The only difference in the code between these two screenshots is that the line window->get_render().attach_new_node(lineNode); was commented in the first screenshot.

[rdb]

Hi,

Which video card do you have exactly?

[JayQc]

I have an nvidia Quadro P620 and an Intel(R) UHD Graphics 630. I’m assuming that the nvidia one is being used, since I can see its memory go up a tiny bit when I launch the program and the computer is set to “performance” mode, but I’m not certain how to validate this.

[rdb]

The reason I ask is since I suspect a driver bug due to switching color formats. You can get information about the driver by setting notify-level-glgsg debug in Config.prc.

What you could do is switch from float color format to uint8 and see if the problem goes away.

[JayQc]

You’re right, it is related to the driver! The problem is only present when I’m using the UHD Graphics 630, it goes away if I force the use of the NVDIA gpu.

Here’s some of the information I got when setting notify-level-glgsg debug:

:display:gsg:glgsg(debug): GL_RENDERER = Intel(R) UHD Graphics 630
:display:gsg:glgsg(debug): GL_VERSION = 4.6.0 - Build 31.0.101.2130
:display:gsg:glgsg(debug): GL_VERSION decoded to: 4.6
:display:gsg:glgsg(debug): GL_SHADING_LANGUAGE_VERSION = 4.60 - Build 31.0.101.2130
:display:gsg:glgsg(debug): Detected GLSL version: 4.60
:display:gsg:glgsg(debug): Using compatibility profile

To switch from float color to uint8, is simply using add_data4i() with regular int good enough? Or do I have to use something a bit lower level than the GeomVertexWriter? I have tried using add_data4i() and the problem did not go away.

[rdb]

Ah, hang on, you’re already using uint8 color. Maybe something else in Panda is enabling BGRA colors on some model. You can try this in Config.prc:

gl-support-vertex-array-bgra false