Opengl line width. Wide lines in geometry shader behaves oddly.

Opengl line width These pages were last compiled on 29 In OpenGL 1. A GLfloat specifying the width of rasterized lines. glHint(GL10. I want the width of lines to be 0. For this test we turned off the multi-sampling, just to demonstrate the visual difference. Hi,my teacher! I want to draw lines with glLineWidth. Line antialiasing is initially disabled. How to draw line in OpenGL? 30. Gdx. lineWidth(width) Parameters. 3. Such is linewidth if you set the linewidth, all lines will be drawn at that width until you change it again. Opengl Es Line thickness. 6. 1, when most of the deprecated features were removed, line width was not among them. Hot Network Questions I might have baked with a possibly rotten egg Why Bitcoin Core uses checkpoints and not the assumevalid block? Revisiting authorship decision ダメ with ようです correct particle What aspect of resetting a NES explains bits of game state being preserved? Is that possible to use the tcolorbox's exercise example in • Understand the role of primitives & vertices in Opengl • Be able to draw points and circles • Understand how the point size it acquired and set • Be able to draw individual lines, connected lines, line strips and loops • Have seen line stippling 2. 52. Using a line width other than 1 has different effects, depending on whether line antialiasing is enabled. OpenGL. I have tried glLineWidth, without any affect. line vertex is too thick (no matter what the width is) 4. Commented Sep 19, 2020 at 13:33. NOTES The line width specified by glLineWidth is always returned when GL_LINE_WIDTH is queried. CPU lines - extending lines to quads on the CPU. Check what your OpenGL implementation actually supports via glGet() and GL_LINE_WIDTH_RANGE. Drawing lines as per screen coords in OpenGL. 2D openGL drawing lines that don't exactly fit pixel raster. 8k Views. js. Improve this question. opengl; glsl; lines; Share. Oldest to Newest; Newest to Oldest I have tried to print the GL_ALIASED_LINE_WIDTH_RANGE variable and it shows interval (1, 7. It works. glLineWidth guarantees to support only width 1. I have tried to print the GL_ALIASED_LINE_WIDTH_RANGE variable and it shows interval (1, 7. (If the rounding results in the value 0, it is as if the line Description. The benefit this gives you is that you do not have to know the original value of the line width in order to restore it. glEnable(GL10. As others have mentioned, this won't smooth polygon edges, but it will create antialiased lines. Anti-aliasing and line width support varies greatly from one driver to the next. OpenGL line width geometry OpenGL is a state machine, so the only important rule is, that you set state when you need it and whenever it changes. 2. ding March 20, 2002, 1:53pm 1. (If the rounding The circular fan on the right is drawn as 1px black lines by cairo_set_line_width (cr, 1. You need a certain line width? Set it and be done width. How can I see if a line width can be supported or not? By using OpenGL: Advanced Coding. However the width of drawed lines looks like 1. Description glLineWidth specifies the rasterized width of both aliased and antialiased lines. The solution is to render lines as I am trying to implement the Line Stipple in OpenGL because the Line stipple API is deprecated. To do this you’d have to implement your own either with polygons or textured polygons. Line width You also need to turn on blending for line smoothing to work. Reply as topic; I have tried to print the GL_ALIASED_LINE_WIDTH_RANGE variable and it shows interval (1, 7. Wide lines in geometry shader behaves oddly. OpenGl es 2. GL_INVALID_VALUE is generated if thx @m-sue for reply It might not be the problem. LineWidth to GL. The order looks for example as follow: v_1_1,v_1_2,v_1_3,v_2_1,v_2_2,v_3_1,. Trouble is, OpenGL only seems to support drawing lines a minumum of 1 pixel wide. In OpenGL 1. If line antialiasing is disabled, the actual width is determined by rounding the supplied width to the nearest integer. In my code, I tried hard to give a 1px #000000 line when you request a 1px #000000 line on the exact OpenGL line width/thickness; OpenGL line width/thickness. You can change the line width with glLineWidth(), but it will still be a fixed width in pixels. Viewed 5k times 3 . answered Jan 22, 2020 at 21:15. How to draw smooth lines with thickness in OpenGL [ES 2] 0. 0 is not required. GLSL 1. Improve this answer. Using a line width other than 1 has different effects, depending on whether line ant Currently there are 5 implementations available in this repo: OpenGL lines - using glLineWidth(width_value) functionality. 0f); glEnd(); Once drawing of primitives was started by glBegin it is only allowed to specify vertex coordinates (glVertex) and Line width may be clamped to an implementation-dependent maximum. 2, the tokens GL_LINE_WIDTH_RANGE and GL_LINE_WIDTH_GRANULARITY were replaced by GL_ALIASED_LINE_WIDTH_RANGE, GL_SMOOTH_LINE_WIDTH_RANGE, and GL_SMOOTH_LINE_WIDTH_GRANULARITY. • The glLineWidthfunction takes a single parameter that specifies the approximate The range of supported widths and the size difference between supported widths within the range can be queried by calling glGet with arguments GL_LINE_WIDTH_RANGE If you want to use core profile OpenGL Context, then you have to use a Shader program and a Vertex Array Object. But you see, the horizontal line is a 2px grey line. 7f, 1. 0 Drawing Rounded Rectangle in DirectX/3D for 2D. GL_INVALID_VALUE is generated if thx @m-sue for reply. I am currently drawing my model right now using a ton of GL_LINES all at a uniform radius. To overcome this limitation, the common suggestion is to "simply" render a rectangle instead. The same is true for OpenGL ES 2. 0 Bezier Curve (Quadratic, Cubic) stroke triangulation on GPU using OpenGL 4. If the user only specifies 1 vertex, the drawing command is ignored. glGet with argument GL_ALIASED_LINE_WIDTH_RANGE. 0? I read something about geometry shader, I am knowing there is another application orientated way to set the line width. OpenGL: Advanced Coding. Sorry , I suppose I meant it the other way round (getting the values first and then asking the question) . However when I see the google map, I found that it can render a much width line for a road like this: What's is the problem? BTW, I wonder if it is desirable to use a game engine in my application? android; opengl-es; Share. Hot Network Questions How does Single Combat handle creatures that can't be sacrificed? Is the wave 4-vector a vector in general relativity? What is the first sci-fi story where a person can travel back in time, not instantaneously, but at a rate of 1s per second? Question about safety of Bluetooth earphones Unix shell increasing line width with Gdx. 9 Speed of quadratic curve. So there's no reason you shouldn't be able to use it in OpenGL 3. lineWidth() method of the WebGL API sets the line width of rasterized lines. How to draw smooth lines with thickness in OpenGL [ES 2] 26. The default line width is 1. 5 or something? I’ve tried that but it crashes my glsl MAT. Setting the Line Width • Specify various line widths when drawing lines by using the glLineWidth function. 0 (no geometry shaders) and desktop OpenGL using only vertex shaders: Generate your vertex data so that you duplicate the vertices for every line I think it's worth pointing out that the linked script, while working and definitely tremendously helpful, is orders of magnitude slower than simply drawing a line in OpenGL All the lines drawn in opengl have the same width, how may I change the width of a line? glLineWidth() Doesn't apear to change the width of lines. Suppose you wanted a line width 1/2 the size of a pixel for a xy image. Is there a possibility to use an index buffer to specify the begin and end indices for each strip in that buffer? OpenGL Line Width GLSL Geometry shader to replace glLineWidth Drawing a variable width line in openGL (No glLineWidth) OpenGL : thick and smooth/non-broken lines in 3D. Follow edited Jan 22, 2020 at 21:23. Line_width not working in Vulkan. draw a line with exact visual length in qt. C++, OpenGL - geometry shader. gl is completely unaffiliated with OpenGL and Khronos. How to change line thickness for OpenGL shapes? 6. Rendering line art with constant screen width. GL_LINES is not always reliable, nor is it flexible enough for most production-quality line rendering. To query the range of supported widths and the size difference between supported widths within the range, call glGet with arguments GL_ALIASED_LINE_WIDTH_RANGE, glLineWidth specifies the rasterized width of both aliased and antialiased lines. In my code, I tried hard to give a 1px #000000 line when you request a 1px #000000 line on the exact pixel coordinate, especially at horizontal/vertical condition. 0; otherwise, Line width less than 1 pixel. 4. glEvalCoord1f((float) i / 10); } gl. To ensure the line was smooth, I used the following: pGL. Call glGet with GL_ALIASED_LINE_WIDTH_RANGE to determine the maximum width. GL_LINE_SMOOTH_HINT, GL10. In particular, a polygon's vertices are lit and the polygon is clipped and possibly culled before OpenGL Line Width. and draw the line within the following loop. openGL: lines with shaders. Or to put that another way, supporting widths > 1. It would be extremely difficult to reproduce the stipple appearance in a shader, and thick lines These were both super-useful features for writing 3D editing software, and my program is worse in OpenGL 4 for their loss. 0. Set the line width before: glLineWidth(3); glBegin(GL_LINES); glVertex2f(-0. 0. Qt OpenGL point size. M 1 Reply In OpenGL Reference Manual, it is written that “Not all widths can be supported when line antialiasing is enabled. Only width 1 is guaranteed to be supported; others depend on the implementation. In general, if you generate bigger geometry (including a full screen quad), you can use the fragment shader to draw smooth lines. I just want to draw a think line!! I have a 3D CAD-like application for which I use OpenGL wrapper library (OpenSceneGraph). Can anyone help me find out if there’s something like gl_LineWidth = . glGet with argument GL_LINE_WIDTH. Description. glEnd(); So the line is drawn and curved. Errors. 4 Saved searches Use saved searches to filter your results more quickly In OpenGL 1. Pixel width using glPointSize - no effect. ukaku ukaku. With non-antialiased wide lines, the line width isn’t measured perpendicular to the line. 375). A linestrip (afaik) can not have it's width changed in a draw state as you say. Associated Gets. Modified 10 years, 7 months ago. Using a line width other than 1. 17. It's OpenGL line width geometry shader. E. 1. Follow edited Mar 28, 2014 at 13:45. , you can use a geometry shader to expand your line to a quad around the ideal line (or, actually two triangles) which can pose as a thick line. How can I draw a line less than 1 pixel wide. The actual width is determined by rounding the supplied width to the nearest integer. To change the width of a single line, set the linewidth you want, draw the line, then set it back to it’s previous width (as demonstrated in the code above). Line Width. width. Using a line width other than 1 has different effects, depending on whether line antialiasing is glLineWidth specifies the rasterized width of lines. I am wondering if Does anyone know how I can set OpenGL line width using GLSL 4. API OpenGL Line Width. GetFloat. I wouldn't be surprised if it topped out at 10. ), I was wondering if Description. Scheduled Pinned Locked Moved Unsolved General and Desktop 6 Posts 3 Posters 7. But the default is 1. Oldest to Newest; Newest to Oldest; Most Votes; Reply. It’s too width for me. g. 0 has different effects, depending on whether OpenGL line width/thickness; QtWS: Super Early Bird Tickets Available! OpenGL line width/thickness. Syntax. The old names are retained for backward compatibility, but should not be used in new code. There are at least two main approaches to draw lines as polygons. OpenGL Line Width (4 answers) Closed 4 years ago. It seems that this is the max width of a line rendered by opengl. GL_LINE_SMOOTH); pGL. 0f); glVertex2f(-0. (If the rounding See OpenGL Line Width for a solution using "modern" OpenGL. Rabbid76 Rabbid76. Decomposing the image with smaller line widths solved the problem. GL_INVALID_VALUE is generated if Line width was never removed from OpenGL. system November 15, 2001, 6:03am 10. thx @m-sue for reply. The default OpenGL drawing of line strip geometry does not allow to render smooth (non-broken) lines, as well as to render them of customary thicker than default width: Not only the connection is smoother, but the line width can be set to any value. If an unsupported width is requested, the nearest supported width is used. To enable and disable line antialiasing, call glEnable and glDisable with argument GL_LINE_SMOOTH. 0 has different effects, depending on whether line antialiasing is enabled. GLSL geometry shader using lines_adjacency. GL_LINE_STRIP); for (int i = 0; i <= 10; i++) { gl. 1k As for the width part you would have to set the width before the call to glBegin(). If line antialiasing is disabled, the actual width is determined by rounding In OpenGL 1. line vertex is too thick (no matter what the width is) 0. Drawing a thick line with legacy OpenGL (immediate mode) in C++. Something like this: OpenGL Line Width. drawing lines on Android with OpenGL ES 1. 14 Is it possible to thicken a quadratic Bézier curve using the GPU only? 0 Drawing bezier curve with limited subdivisions in OpenGL. You can use glPushAttrib (GL_LINE_BIT) before you set the line width for one line and glPopAttrib when you are done drawing that line. 5 Simple Geometry shader. 6 Resolution independent cubic bezier drawing on GPU (Blinn/Loop) 5 Bezier curve using c++ opengl. Hot Network Questions You set a state and it stays that way until you change it again. GLSL, adding a single line makes nothing draw. Thanks! The glLineWidth function specifies the rasterized width of both aliased and antialiased lines. 4k Views. To enable glLineWidth specifies the rasterized width of both aliased and antialiased lines. gl. glLineWidth(): a bug causes angles to appear on the ring, because the circle is actually made of several segments (see other question for illustration) drawing two circles one onto another, and rotate the second one of 45 degrees to hide these angles, but that doesn't suit me because my circle has an alpha OpenGL line width geometry shader. O I have forgotten, there is a way to change the values by a other Graphic Card g. How to draw lines with a certain amount of thickness. It is not allowed to call glLineWidth with in a glBegin/glEnd sequence. xill November 16, 2001, 2:15am 11. OpenGL Line Width. Rendering line art with The maximum line width supported must be at least one. To enable and disable line antialiasing, call glEnable and glDisable with argument GL_LINE_SMOOTH . Return value. glLineWidth specifies the rasterized width of both aliased and antialiased lines. 0) Dynamically Change Line Width. Using a line width other than 1 has different effects, depending on whether line antialiasing is enabled. – Rabbid76. Since this seems like a basic requirement (render 2D/3D lines of arbitrary width, mesh wireframe, etc. gl. 2. Another, more general I there a programmatical way (e. OpenGL line thickness. This may not be the most efficient way, but it works. Antialiased lines using jogl on Windows 7 look horrible. ”. glBegin(GL. In addition to setting the line width and setting anti-aliasing you can also specify a stipple pattern. Draw lines with custom thickness with Pyglet/OpenGL? 3. M 1 Reply Last This isn't a problem with line strips. The ARB didn’t As with point sizes, a particular OpenGL implementation might limit the width of non-antialiased lines to its maximum antialiased line width, rounded to the nearest integer value. 211k 30 30 gold badges 156 156 silver badges 199 199 bronze GL_LINE_LOOP: As line strips, except that the first and last vertices are also used as a line. API Create points and draw a polygon between them to create the desired thickness. Thats the same as drawing the line with a width of 1 pixel Drawing a continuous, curvy line in OpenGL with arbitrary width. for each vertex v_i_j where i is the index of the strip and j the index of the vertex in the strip. It may also help to set the line width to a non-integral width. Even if wide lines are supported, OpenGL’s line rasterisation doesn’t support joins, so there will be noticeable gaps at the vertices for widths much larger than 1. glPolygonMode controls the interpretation of polygons for rasterization. why Description [] glLineWidth specifies the rasterized width of both aliased and antialiased lines. I know that glLineWidth will change the radius of the all the lines but they each should have a different radius. getParameter(gl. Just set the stroke() to a value that contains an alpha. OpenGL command) to determine the maximal line width IN PIXELS supported by my GPU's OpenGL implementation? I recently worked with a OpenGL buffer with width ~50000 pixels and got bad results. docs. The default is 1. This tutorial is perfect for Line width may be clamped to an implementation-dependent maximum. In my case, i really need this lines As with points, OpenGL allows you to change several parameters of the state machine that affect how your line is drawn. Line antialiasing is controlled by calling glEnable and glDisable with argument GL_LINE_SMOOTH. OpenGL is doing exactly what you have asked it to do: draw a bunch of rectangles oriented to match the 'lines' you've provided, each with a particular width which you've also provided. API The WebGLRenderingContext. Is it possible to draw line thickness in a fragment shader? 0. To do so you have to check the join-angle, the width of the line and the length of the joined line-segments (line OpenGL (ES 2. Add a comment | Related questions. To find out the currently selected line with pass GetPName. Now yes, MacOS's OpenGL support doesn't let • Understand the role of primitives & vertices in Opengl • Be able to draw points and circles • Understand how the point size it acquired and set • Be able to draw individual lines, connected lines, line strips and loops • Have seen line stippling 2. I have an application that involves some lines, and I would like to draw realistic 3d line widths. 191 2 2 silver badges 11 11 bronze glGetFloatv(GL_LINE_WIDTH_RANGE, lineWidth); say you what your OpenGL implementatin suport. GLSL Geometry shader to replace Set the OpenGL line width. However, if you are using a core OpenGL context and the forward In OpenGL 1. glLineStipple is deprecated, as is GL_LINE_SMOOTH. Python Qt bindings: How to increase the width of lines with width 0. Using a line width other than 1 has different effects, depending on whether line ant OpenGL support for line drawing fairly basic. You need a number of different line widths in a single code segment: Sort by line width and set once for every line width. Clamping and rounding for aliased and Line width is controlled by glLineWidth, but the set of supported widths is implementation-dependent. M 1 Reply Line width may be clamped to an implementation-dependent maximum. The glLineWidth function specifies the rasterized width of both aliased and antialiased lines. But the problem is, when i increment the line-width, V-shaped gaps are appearing between the stippled lines. • The glLineWidthfunction Call glGet with GL_ALIASED_LINE_WIDTH_RANGE to determine the maximum width. 0 draw line with color. Ask Question Asked 12 years ago. All vertices are in one common buffer. Try: glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); and then drawing lines. Thus, you get n lines for n input vertices. Only a width of 1 is guaranteed to be supported. I created a function to do this with each point. The range of supported widths and the size difference between supported widths within the range can be queried by calling glGet with arguments GL_LINE_WIDTH_RANGE and GL_LINE_WIDTH_GRANULARITY. 5); line(0, 0, width, height); More info can be found in the reference. GL_NICEST); However, this essentially means I cannot control the width of the line, as it #opengl #shaders #line In this video, I'll show you how to draw lines with adjustable thickness using shaders vao vbo in OpenGL. 7f, -1. lineWidth(5); Getting the line width: js. It was deprecated, but in 3. Unfortunately, drawing lines is a weak point of OpenGL. Commented Sep 19, 2020 at 13:39. • The glLineWidthfunction I want to draw multiple line strips of different length. . GL_INVALID_VALUE is generated if As the user swipes their finger across the screen, this produces a line following their finger. 3gl Name glLineWidth - specify the width of rasterized lines C Specification void glLineWidth( GLfloat width) Parameters width Specifies the width of rasterized lines. If I set my hardware to oversampling, I can Line width may be clamped to an implementation-dependent maximum. Setting the line width: js. 13 OpenGL line width/thickness; QtWS: Super Early Bird Tickets Available! OpenGL line width/thickness. surfdabbler March 8, 2007, 10:03pm 1. Oldest to Newest. OpenGL line width GL_LINE_LOOP: As line strips, except that the first and last vertices are also used as a line. 1+ core profile. Hi there, I’ve had some luck with assigning floats to the gl_PointSize variable, but I haven’t figured anything out for changing the width of my the line_strip primitive that I’m producing. face describes which polygons mode applies to: both front and back-facing polygons (GL_FRONT_AND_BACK). Default value: 1. Follow asked Jun 2, 2013 at 1:07. ALIASED_LINE_WIDTH_RANGE) which returns an array of 2 numbers. It is working fine for lines and Polygons but It is not working for Circle. Android OpenGL ES Line antialiase. To find out the minimum and maximum width supported for a line you're supposed to call gl. 9k Views. is there any problem with These were both super-useful features for writing 3D editing software, and my program is worse in OpenGL 4 for their loss. Hot Network Questions VT320 over ttyUSB0 crashes when encountering emoji XOR sum versus additive sum for parallelizable hash Is a person free to say anything before signing an NDA? Why is a smooth morphism so much more restrictive in algebraic geometry than differential topology? Doesn't saving an SSH passphrase Drawing arbitrary 2D lines in OpenGL and OpenGL ES can be a bit tricky. The polygon mode affects only the final rasterization of polygons. The GL_LINES drawing mode is limited: it does not support line Write yourself a routine that checks if the joins can be constructed from simple geometry without problems. Lines of width 1 look OK and require no capping, lines of width greater than 1 are usually implemented by expanding vertically or horizontally depending on slope. Color picking wide lines on 1x1 viewport not working in OpenGL. Any smaller, and they stay at 1 pixel. I created a function on desmos which takes two points and finds new points to create the desired thickness T. Thanks in advance! All Content Blogs Forums News Tutorials For a "modern" solution see OpenGL Line Width. Other solutions are a to draw a texture and use Blending or draw a rectangle and discard fragments in the fragment shader. By a brief benchmark, it is 30 times faster than OpenGL native strokeWeight(. On Windows, it's limited to width 10. Anyway if you want to use a geometry shader, transform the vertex coordinate with the model view projection matrix in the vertex shader: #version 330 in vec4 a_position; uniform mat4 u_modelviewprojection_matrix; void main() { gl_Position = OpenGL man pages glLineWidth. How to draw a A possible solution without using a geometry shader is presented in the answer to OpenGL Line Width. glLineWidth(32); // Or whatever thickness you need // Then render the lines or circles as per what you're currently doing shape Remarks. One vertex buffer with varying width. My first issue is that w = 10 or w = 3000 (or any larger number) shows the same line thickness, but something smaller like w=3 produces a thinner line. You can use the class QLineWidth to set the width of rendered lines or QPointSize to set the size of points. 0 / WebGL1. Also, in OpenGL ES, implementations are only required to support line widths up to 1. GL_INVALID_VALUE is generated if width is less than or equal to 0. Share. Maps are mostly made up of lines, as well as the occasional polygon thrown in. Just don't create a "forward compatibility context", and you should be fine. For the application I am trying to come up with the best strategy on how to render thick and smooth lines in 3D. You would have to end the draw call, change the width, go 1 vertex back and start a new draw call. None (undefined). By thick and In OpenGL 1. Or if you want to align more closely with the OpenGL approaches If line is thiner than 1 pixel, draw 1-pixel line but use alpha blending to make it partially visible. 0). It might not be the problem. genpfault. GL_INVALID_VALUE is generated if Pass in two vertices and a line width, generate 4 points forming two triangles by shifting the vertices, render and be done But drawing wide lines using triangles w/o a geometry shader can also be done in OpenGL ES 2. Examples. If line antialiasing is disabled, the actual width is determined By Konstantin Käfer. It does not explicitly support any kind of capping. Instead, it’s measured in the y-direction if the absolute value of the slope is less than 1. OpenGL line width geometry shader. The line between the first and last vertices happens after all of the previous lines in the sequence. @Shuvo0o: Since you are using deprecated OpenGL, you still have access to the attrib stack. LINE_WIDTH); The circular fan on the right is drawn as 1px black lines by cairo_set_line_width (cr, 1. fptoold zwwojg klek qnh jdfj ofze grber aiveiwz ltnddfn pgdcdw okqg hquur blzwzu vhl ism