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    • By lxjk
      Hi guys,
      There are many ways to do light culling in tile-based shading. I've been playing with this idea for a while, and just want to throw it out there.
      Because tile frustums are general small compared to light radius, I tried using cone test to reduce false positives introduced by commonly used sphere-frustum test.
      On top of that, I use distance to camera rather than depth for near/far test (aka. sliced by spheres).
      This method can be naturally extended to clustered light culling as well.
      The following image shows the general ideas

      Performance-wise I get around 15% improvement over sphere-frustum test. You can also see how a single light performs as the following: from left to right (1) standard rendering of a point light; then tiles passed the test of (2) sphere-frustum test; (3) cone test; (4) spherical-sliced cone test

      I put the details in my blog post (https://lxjk.github.io/2018/03/25/Improve-Tile-based-Light-Culling-with-Spherical-sliced-Cone.html), GLSL source code included!
    • By Fadey Duh
      Good evening everyone!

      I was wondering if there is something equivalent of  GL_NV_blend_equation_advanced for AMD?
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    • By Jens Eckervogt
      Hello guys, 
      Please tell me! 
      How do I know? Why does wavefront not show for me?
      I already checked I have non errors yet.
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      Please help me how do I fix.

      And my download (mega.nz) should it is original but I tried no success...
      - Add blend source and png file here I have tried tried,.....  
      PS: Why is our community not active? I wait very longer. Stop to lie me!
      Thanks !
    • By codelyoko373
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    • By Jens Eckervogt
      Hello everyone, 
      I have problem with texture
      using System; using OpenTK; using OpenTK.Input; using OpenTK.Graphics; using OpenTK.Graphics.OpenGL4; using System.Drawing; using System.Reflection; namespace Tutorial_05 { class Game : GameWindow { private static int WIDTH = 1200; private static int HEIGHT = 720; private static KeyboardState keyState; private int vaoID; private int vboID; private int iboID; private Vector3[] vertices = { new Vector3(-0.5f, 0.5f, 0.0f), // V0 new Vector3(-0.5f, -0.5f, 0.0f), // V1 new Vector3(0.5f, -0.5f, 0.0f), // V2 new Vector3(0.5f, 0.5f, 0.0f) // V3 }; private Vector2[] texcoords = { new Vector2(0, 0), new Vector2(0, 1), new Vector2(1, 1), new Vector2(1, 0) }; private int[] indices = { 0, 1, 3, 3, 1, 2 }; private string vertsrc = @"#version 450 core in vec3 position; in vec2 textureCoords; out vec2 pass_textureCoords; void main(void) { gl_Position = vec4(position, 1.0); pass_textureCoords = textureCoords; }"; private string fragsrc = @"#version 450 core in vec2 pass_textureCoords; out vec4 out_color; uniform sampler2D textureSampler; void main(void) { out_color = texture(textureSampler, pass_textureCoords); }"; private int programID; private int vertexShaderID; private int fragmentShaderID; private int textureID; private Bitmap texsrc; public Game() : base(WIDTH, HEIGHT, GraphicsMode.Default, "Tutorial 05 - Texturing", GameWindowFlags.Default, DisplayDevice.Default, 4, 5, GraphicsContextFlags.Default) { } protected override void OnLoad(EventArgs e) { base.OnLoad(e); CursorVisible = true; GL.GenVertexArrays(1, out vaoID); GL.BindVertexArray(vaoID); GL.GenBuffers(1, out vboID); GL.BindBuffer(BufferTarget.ArrayBuffer, vboID); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(vertices.Length * Vector3.SizeInBytes), vertices, BufferUsageHint.StaticDraw); GL.GenBuffers(1, out iboID); GL.BindBuffer(BufferTarget.ElementArrayBuffer, iboID); GL.BufferData(BufferTarget.ElementArrayBuffer, (IntPtr)(indices.Length * sizeof(int)), indices, BufferUsageHint.StaticDraw); vertexShaderID = GL.CreateShader(ShaderType.VertexShader); GL.ShaderSource(vertexShaderID, vertsrc); GL.CompileShader(vertexShaderID); fragmentShaderID = GL.CreateShader(ShaderType.FragmentShader); GL.ShaderSource(fragmentShaderID, fragsrc); GL.CompileShader(fragmentShaderID); programID = GL.CreateProgram(); GL.AttachShader(programID, vertexShaderID); GL.AttachShader(programID, fragmentShaderID); GL.LinkProgram(programID); // Loading texture from embedded resource texsrc = new Bitmap(Assembly.GetEntryAssembly().GetManifestResourceStream("Tutorial_05.example.png")); textureID = GL.GenTexture(); GL.BindTexture(TextureTarget.Texture2D, textureID); GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)All.Linear); GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)All.Linear); GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, texsrc.Width, texsrc.Height, 0, PixelFormat.Bgra, PixelType.UnsignedByte, IntPtr.Zero); System.Drawing.Imaging.BitmapData bitmap_data = texsrc.LockBits(new Rectangle(0, 0, texsrc.Width, texsrc.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppRgb); GL.TexSubImage2D(TextureTarget.Texture2D, 0, 0, 0, texsrc.Width, texsrc.Height, PixelFormat.Bgra, PixelType.UnsignedByte, bitmap_data.Scan0); texsrc.UnlockBits(bitmap_data); GL.Enable(EnableCap.Texture2D); GL.BufferData(BufferTarget.TextureBuffer, (IntPtr)(texcoords.Length * Vector2.SizeInBytes), texcoords, BufferUsageHint.StaticDraw); GL.BindAttribLocation(programID, 0, "position"); GL.BindAttribLocation(programID, 1, "textureCoords"); } protected override void OnResize(EventArgs e) { base.OnResize(e); GL.Viewport(0, 0, ClientRectangle.Width, ClientRectangle.Height); } protected override void OnUpdateFrame(FrameEventArgs e) { base.OnUpdateFrame(e); keyState = Keyboard.GetState(); if (keyState.IsKeyDown(Key.Escape)) { Exit(); } } protected override void OnRenderFrame(FrameEventArgs e) { base.OnRenderFrame(e); // Prepare for background GL.Clear(ClearBufferMask.ColorBufferBit); GL.ClearColor(Color4.Red); // Draw traingles GL.EnableVertexAttribArray(0); GL.EnableVertexAttribArray(1); GL.BindVertexArray(vaoID); GL.UseProgram(programID); GL.BindBuffer(BufferTarget.ArrayBuffer, vboID); GL.VertexAttribPointer(0, 3, VertexAttribPointerType.Float, false, 0, IntPtr.Zero); GL.ActiveTexture(TextureUnit.Texture0); GL.BindTexture(TextureTarget.Texture3D, textureID); GL.BindBuffer(BufferTarget.ElementArrayBuffer, iboID); GL.DrawElements(BeginMode.Triangles, indices.Length, DrawElementsType.UnsignedInt, 0); GL.DisableVertexAttribArray(0); GL.DisableVertexAttribArray(1); SwapBuffers(); } protected override void OnClosed(EventArgs e) { base.OnClosed(e); GL.DeleteVertexArray(vaoID); GL.DeleteBuffer(vboID); } } } I can not remember where do I add GL.Uniform2();
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OpenGL unicode fonts

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Hi! I wanted to support unicode in my game, but I'm thinking how to get it to draw on opengl. Can I generate bitmap fonts for all the chars in unicode? (I think it'll use too much video memory) If I create a texture for each string on demand, and upload it to the video card, will it be too slow? or you guys have other ways of dealing it? thanks

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hey ,

i think loading all maps in VRAM will be kinda expensive so try to load them in RAM and bind them to VRAM when u need it and free it when u done from it.

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There are a lot of glyphs in Unicode. Trying to create a bitmap for each one would not be a good idea. If you plan to support arbitrary Unicode text then you should consider rendering as needed from a font.

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ohboy this question was for me
As already pointed out you probably don't want to do this with texture fonts. Of course you could have a default 16x16 glyph size, and generate 1-bit textures (say 256 glyphs on a 256x256 texture) for every character in the basic multilingual plane, at a cost of 256 textures, or a little over 2MB disk space. I almost did this because it would mean the unicode rendering is completely self contained and portable.

However, apart from being stuck with only one (aliased) font, the resulting text would be quite fugly having commas the same width as 'w' for example. Also when you show characters larger than the size they are in the texture, it would be fuglier than fugly. There would probably be a marginal speed hit too, unless you did something clever to reduce the number of texture binds necessary per frame. I still dont think its such a bad idea, but in the end I went with using wglUseFontOutlines to make a display list for each character. This function also gives you the dimensions of the glyph which you can use for a bunch of things: checking if it should be rendered or will need to have a line break, checking if mouse is over it, rendering text as 'selected' by the user etc. Since the display list for the character is made up of lines/polygons, you can do all kinds of 3D rendering with them which you cant do with texture fonts.

Anyway, allow me to contribute some code that I lost a lot of hair making. Here are a couple of functions from my UnicodeString class, with relevant support functions for them. buildDisplayLists takes a wstring and iterates over the characters in it to create a display list for each one, and puts them in a map. The map makes sure you dont create any redundant lists. The result is stored as an array of GLuints in the class, these are the ids of the display lists which need to be called to draw the whole string. Each characters display list includes a glTranslate to position ready for the next character, so you can see the render function just does glCallLists.
Admittedly the characters do look kinda crusty when displayed very small, but they scale up nicely.

You can't just pop in some Thai/Arabic/Big5 text and expect it to work. Most fonts will only contain a subset of unicode glyphs. For example, the font I used here is "MS UI Gothic". As far as I know this is the font windows uses by default for all its menus and on my pc this includes Japanese glyphs but not Korean, so I need to change the font to something else to view Korean. On your pc you may not have either of these. Also within a font there can be more than one character set. This may also need changing in order to see what you are expecting to see, but so far I havent found it necessary.

HFONT oldfont = NULL, newfont = NULL;

void selectFont()
int nHeight = -MulDiv(12, GetDeviceCaps(hDC, LOGPIXELSY), 72);
LOGFONT logfont;
logfont.lfHeight = nHeight;
logfont.lfWidth = 0;
logfont.lfEscapement = 0;
logfont.lfOrientation = 0;
logfont.lfWeight = FW_NORMAL;
logfont.lfItalic = FALSE;
logfont.lfUnderline = FALSE;
logfont.lfStrikeOut = FALSE;
logfont.lfCharSet = DEFAULT_CHARSET;
logfont.lfOutPrecision = OUT_DEFAULT_PRECIS;
logfont.lfClipPrecision = CLIP_DEFAULT_PRECIS;
logfont.lfQuality = DEFAULT_QUALITY;
logfont.lfPitchAndFamily= FF_DONTCARE|DEFAULT_PITCH;
lstrcpy( logfont.lfFaceName, "MS UI Gothic" );
//lstrcpy( logfont.lfFaceName, "Comic Sans MS" );

newfont = CreateFontIndirect( &logfont );
if (!newfont)
fileLog.log(LL_ERROR, "CreateFontIndirect failed");
oldfont = (HFONT)SelectObject( hDC, newfont );
if (!oldfont)
fileLog.log(LL_ERROR, "SelectObject failed");
assert( oldfont );

void releaseFont()
if (!oldfont)
fileLog.log(LL_ERROR, "SelectObject failed (%s)", __FUNCTION__);
SelectObject(hDC, oldfont);

//these are members of UnicodeString class
int length;
GLuint* lists;
BoundingBox boundingBox;
static map<wchar_t, characterData*> characterCache;

void UnicodeString::buildDisplayLists(wstring _text)
length = (int)_text.length();

lists = new GLuint[length];
glyphMetrics = new GLYPHMETRICSFLOAT[length];

for (int i = 0; i < length; i++) {
map<unsigned short, characterData*>::iterator it = characterCache.find(text);
if (it != characterCache.end()) {
characterData* cd = (*it).second;
lists = cd->listId;
glyphMetrics = cd->glyphMetrics;
lists = glGenLists(1);
int e = glGetError();
if (!lists) {
fileLog.log(LL_ERROR, "glGenLists failed, glGetError = %d", e);
continue;// or... ?
BOOL ok = wglUseFontOutlinesW( hDC, text, 1, lists, 0, 0, WGL_FONT_POLYGONS, &glyphMetrics);
e = glGetError();
assert(ok || !e);
if (!ok)
fileLog.log(LL_ERROR, "wglUseFontOutlines failed, glGetError = %d", e);
characterData* cd = new characterData;
cd->listId = lists;
cd->glyphMetrics = glyphMetrics;
characterCache[text] = cd;

boundingBox = BoundingBox();
float baseX = 0, baseY = 0;
for (int i = 0; i < length; i++) {
boundingBox.expandToCover(baseX + g.gmfptGlyphOrigin.x, -0.15f);
boundingBox.expandToCover(baseX + g.gmfptGlyphOrigin.x+g.gmfBlackBoxX, -0.15f);
boundingBox.expandToCover(baseX + g.gmfptGlyphOrigin.x+g.gmfBlackBoxX, 0.88f);
boundingBox.expandToCover(baseX + g.gmfptGlyphOrigin.x, 0.85f);
baseX += g.gmfCellIncX;
baseY += g.gmfCellIncY;

void UnicodeString::renderText()
//set color,translation,rotation,scale etc here
//scale should be roughly the height in pixels that you want the character to be
glCallLists(length, GL_UNSIGNED_INT, lists);

Some screens of this.

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