Support for 3d images in the renderer.

Quik.Media.Defaults/QImageStbi.cs

@@ -11,12 +11,14 @@ namespace Quik.Media.Defaults
     {
         private readonly StbImage image;
         private QImageBuffer buffer;
+        private bool isSdf = false;
 
         public override int Width => image.Width;
 
         public override int Height => image.Height;
 
         public override int Depth => 1;
+        public override bool IsSdf => isSdf;
         public override QImageFormat InternalFormat => Stb2QImageFormat(image.Format);
 
         public QImageStbi(Stream source)
@@ -79,6 +81,11 @@ namespace Quik.Media.Defaults
             buffer.UnlockBits();
         }
 
+        public void SdfHint(bool value = true)
+        {
+            isSdf = value;
+        }
+
         protected override void Dispose(bool disposing)
         {
             base.Dispose(disposing);

Quik/CommandMachine/CommandList.cs

@@ -1,3 +1,4 @@
+using Quik.Media;
 using System;
 using System.Collections;
 using System.Collections.Generic;
@@ -214,7 +215,7 @@ namespace Quik.CommandMachine
             }
         }
 
-        public void Image(QuikTexture texture, in QRectangle rectangle)
+        public void Image(QImage texture, in QRectangle rectangle)
         {
             Enqueue(Command.Image);
             Enqueue((Frame)(int)ImageCommandFlags.Single);
@@ -222,7 +223,7 @@ namespace Quik.CommandMachine
             Enqueue(rectangle);
         }
 
-        public void Image(QuikTexture texture, in QRectangle rectangle, in QRectangle uv)
+        public void Image(QImage texture, in QRectangle rectangle, in QRectangle uv)
         {
             Enqueue(Command.Image);
             Enqueue((Frame)(int)(ImageCommandFlags.Single | ImageCommandFlags.UVs));
@@ -231,7 +232,7 @@ namespace Quik.CommandMachine
             Enqueue(uv);
         }
 
-        public void Image(QuikTexture texture, ReadOnlySpan<QRectangle> rectangles, bool interleavedUV = false)
+        public void Image(QImage texture, ReadOnlySpan<QRectangle> rectangles, bool interleavedUV = false)
         {
             int count = rectangles.Length;
             ImageCommandFlags flags = ImageCommandFlags.None;
@@ -252,7 +253,7 @@ namespace Quik.CommandMachine
             }
         }
 
-        public void Image(QuikTexture texture, ReadOnlySpan<QRectangle> rectangles, ReadOnlySpan<QRectangle> uvs)
+        public void Image(QImage texture, ReadOnlySpan<QRectangle> rectangles, ReadOnlySpan<QRectangle> uvs)
         {
             int count = Math.Min(rectangles.Length, uvs.Length);
             Enqueue(Command.Image);
@@ -266,7 +267,7 @@ namespace Quik.CommandMachine
             }
         }
 
-        public void Image3D(QuikTexture texture, in Image3DCall call)
+        public void Image3D(QImage texture, in Image3DCall call)
         {
             Enqueue(Command.Image);
             Enqueue(new Frame(ImageCommandFlags.Image3d | ImageCommandFlags.Single));
@@ -276,7 +277,7 @@ namespace Quik.CommandMachine
             Enqueue(new Frame(call.Layer));
         }
 
-        public void Image3D(QuikTexture texture, ReadOnlySpan<Image3DCall> calls)
+        public void Image3D(QImage texture, ReadOnlySpan<Image3DCall> calls)
         {
             Enqueue(Command.Image);
             Enqueue(new Frame((int)ImageCommandFlags.Image3d, calls.Length));

Quik/Media/QImage.cs

@@ -10,6 +10,7 @@ namespace Quik.Media
         public abstract QImageFormat InternalFormat { get; }
         public virtual int MipMapLevels => 0;
         public virtual bool Premultiplied => false;
+        public virtual bool IsSdf => false;
 
         public abstract void LockBits2d(out QImageLock imageLock, QImageLockOptions options);
         public abstract void LockBits3d(out QImageLock imageLock, QImageLockOptions options);

Quik/OpenGL/GL.Texture.cs

@@ -9,7 +9,9 @@ namespace Quik.OpenGL
         private delegate void PixelStoreiProc(GLEnum pname, int param);
         private delegate void PixelStorefProc(GLEnum pname, float param);
         private delegate void TexImage2DProc(GLEnum target, int level, GLEnum internalFormat, int width, int height, int border, GLEnum format, GLEnum pixelType, void *data);
+        private delegate void TexImage3DProc(GLEnum target, int level, GLEnum internalFormat, int width, int height, int depth, int border, GLEnum format, GLEnum pixelType, void* data);
         private delegate void TexSubImage2DProc(GLEnum target, int level, int x, int y, int width, int height, GLEnum format, GLEnum pixelType, void *data);
+        private delegate void TexSubImage3DProc(GLEnum target, int level, int x, int y, int z, int width, int height, int depth, int border, GLEnum format, GLEnum pixelType, void* data);
         private delegate void TexParameteriProc(GLEnum target, GLEnum pname, int value);
         private delegate void TexParameterfProc(GLEnum target, GLEnum pname, float value);
         private delegate void TexParameterivProc(GLEnum target, GLEnum pname, int* value);
@@ -23,7 +25,9 @@ namespace Quik.OpenGL
         private static PixelStoreiProc _pixelStorei;
         private static PixelStorefProc _pixelStoref;
         private static TexImage2DProc _texImage2D;
+        private static TexImage3DProc _texImage3D;
         private static TexSubImage2DProc _texSubImage2D;
+        private static TexSubImage3DProc _texSubImage3D;
         private static TexParameteriProc _texParameteri;
         private static TexParameterfProc _texParameterf;
         private static TexParameterivProc _texParameteriv;
@@ -39,7 +43,9 @@ namespace Quik.OpenGL
             _pixelStorei    = GetProcAddress<PixelStoreiProc>("glPixelStorei");
             _pixelStoref    = GetProcAddress<PixelStorefProc>("glPixelStoref");
             _texImage2D     = GetProcAddress<TexImage2DProc>("glTexImage2D");
+            _texImage3D     = GetProcAddress<TexImage3DProc>("glTexImage3D");
             _texSubImage2D  = GetProcAddress<TexSubImage2DProc>("glTexSubImage2D");
+            _texSubImage3D  = GetProcAddress<TexSubImage3DProc>("glTexSubImage3D");
             _texParameteri  = GetProcAddress<TexParameteriProc>("glTexParameteri");
             _texParameterf  = GetProcAddress<TexParameterfProc>("glTexParameterf");
             _texParameteriv = GetProcAddress<TexParameterivProc>("glTexParameteriv");
@@ -92,7 +98,7 @@ namespace Quik.OpenGL
             _texImage2D(target, level, internalFormat, width, height, border, format, pixelType, (void*)data);
 
         [MethodImpl(AggressiveInlining)]
-        public static void TexImage2d<T>(GLEnum target, int level, GLEnum internalFormat, int width, int height, int border, GLEnum format, GLEnum pixelType, in T data) where T : unmanaged
+        public static void TexImage2D<T>(GLEnum target, int level, GLEnum internalFormat, int width, int height, int border, GLEnum format, GLEnum pixelType, in T data) where T : unmanaged
         {
             fixed(T *ptr = &data)
                 _texImage2D(target, level, internalFormat, width, height, border, format, pixelType, ptr);
@@ -100,7 +106,24 @@ namespace Quik.OpenGL
 
         [MethodImpl(AggressiveInlining)]
         public static void TexImage2D<T>(GLEnum target, int level, GLEnum internalFormat, int width, int height, int border, GLEnum format, GLEnum pixelType, T[] data) where T : unmanaged =>
-            TexImage2d<T>(target, level, internalFormat, width, height, border, format, pixelType, in data[0]);
+            TexImage2D(target, level, internalFormat, width, height, border, format, pixelType, in data[0]);
+
+        [MethodImpl(AggressiveInlining)]
+        public static void TexImage3D(GLEnum target, int level, GLEnum internalFormat, int width, int height, int depth, int border, GLEnum format, GLEnum pixelType, void* data) =>
+            _texImage3D(target, level, internalFormat, width, height, depth, border, format, pixelType, data);
+
+        [MethodImpl(AggressiveInlining)]
+        public static void TexImage3D<T>(GLEnum target, int level, GLEnum internalFormat, int width, int height, int depth, int border, GLEnum format, GLEnum pixelType, in T data)
+            where T : unmanaged
+        {
+            fixed (T* ptr = &data)
+                _texImage3D(target, level, internalFormat, width, height, depth, border, format, pixelType, ptr);
+        }
+
+        [MethodImpl(AggressiveInlining)]
+        public static void TexImage3D<T>(GLEnum target, int level, GLEnum internalFormat, int width, int height, int depth, int border, GLEnum format, GLEnum pixelType, T[] data)
+            where T : unmanaged =>
+                TexImage3D(target, level, internalFormat, width, height, depth, border, format, pixelType, in data[0]);
 
         [MethodImpl(AggressiveInlining)]
         public static void TexSubImage2D(GLEnum target, int level, int x, int y, int width, int height, GLEnum format, GLEnum pixelType, IntPtr data) =>
@@ -117,6 +140,23 @@ namespace Quik.OpenGL
         public static void TexSubImage2D<T>(GLEnum target, int level, int x, int y, int width, int height, GLEnum format, GLEnum pixelType, T[] data) where T : unmanaged =>
             TexSubImage2d<T>(target, level, x, y, width, height, format, pixelType, in data[0]);
 
+        [MethodImpl(AggressiveInlining)]
+        public static void TexSubImage3D(GLEnum target, int level, int x, int y, int z, int width, int height, int depth, int border, GLEnum format, GLEnum pixelType, void* data) =>
+            _texSubImage3D(target, level, x, y, z, width, height, depth, border, format, pixelType, data);
+
+        [MethodImpl(AggressiveInlining)]
+        public static void TexSubImage3D<T>(GLEnum target, int level, int x, int y, int z, int width, int height, int depth, int border, GLEnum format, GLEnum pixelType, in T data)
+            where T : unmanaged
+        {
+            fixed (T* ptr = &data)
+                _texSubImage3D(target, level, x, y, z, width, height, depth, border, format, pixelType, ptr);
+        }
+
+        [MethodImpl(AggressiveInlining)]
+        public static void TexSubImage3D<T>(GLEnum target, int level, int x, int y, int z, int width, int height, int depth, int border, GLEnum format, GLEnum pixelType, T[] data)
+            where T : unmanaged =>
+                TexSubImage3D(target, level, x, y, z, width, height, depth, border, format, pixelType, in data[0]);
+
         [MethodImpl(AggressiveInlining)]
         public static void TexParameter(GLEnum target, GLEnum pname, int value) => _texParameteri(target, pname, value);
         [MethodImpl(AggressiveInlining)]

Quik/OpenGL/GL21Driver.cs

@@ -3,6 +3,8 @@ using System.IO;
 using System.Collections.Generic;
 using Quik.VertexGenerator;
 using static Quik.OpenGL.GLEnum;
+using Quik.Media;
+using System.Linq;
 
 namespace Quik.OpenGL
 {
@@ -10,18 +12,23 @@ namespace Quik.OpenGL
     {
         private int program;
         private int v2Position;
-        private int iZIndex;
+        private int fZIndex;
         private int v2TexPos;
+        private int fTexLayer;
         private int v4Color;
         private int m4Transforms;
-        private int iMaxZ;
+        private int fMaxZ;
         private int iEnableSdf;
         private int iEnableTexture;
         private int iAlphaDiscard;
         private int fSdfThreshold;
-        private int txTexture;
+        private int tx2d;
+        private int tx2darray;
+
         private bool isDiposed;
         private readonly Dictionary<DrawQueue, DrawData> data = new Dictionary<DrawQueue, DrawData>();
+        private readonly TextureManager textures = new TextureManager();
+
         public bool IsInit { get; private set; } = false;
         public event Action<GL21Driver> OnGCDispose;
 
@@ -57,16 +64,19 @@ namespace Quik.OpenGL
             GL.DeleteShader(fs);
 
             v2Position = GL.GetAttribLocation(program, nameof(v2Position));
-            iZIndex    = GL.GetAttribLocation(program, nameof(iZIndex));
+            fZIndex    = GL.GetAttribLocation(program, nameof(fZIndex));
             v2TexPos   = GL.GetAttribLocation(program, nameof(v2TexPos));
+            fTexLayer  = GL.GetAttribLocation(program, nameof(fTexLayer));
             v4Color    = GL.GetAttribLocation(program, nameof(v4Color));
 
             m4Transforms   = GL.GetUniformLocation(program, nameof(m4Transforms));
-            iMaxZ          = GL.GetUniformLocation(program, nameof(iMaxZ));
+            fMaxZ          = GL.GetUniformLocation(program, nameof(fMaxZ));
+            fSdfThreshold  = GL.GetUniformLocation(program, nameof(fSdfThreshold));
             iEnableSdf     = GL.GetUniformLocation(program, nameof(iEnableSdf));
-            iEnableTexture = GL.GetUniformLocation(program, nameof(iEnableSdf));
+            iEnableTexture = GL.GetUniformLocation(program, nameof(iEnableTexture));
             iAlphaDiscard  = GL.GetUniformLocation(program, nameof(iAlphaDiscard));
-            txTexture      = GL.GetUniformLocation(program, nameof(txTexture));
+            tx2d           = GL.GetUniformLocation(program, nameof(tx2d));
+            tx2darray      = GL.GetUniformLocation(program, nameof(tx2darray));
 
             IsInit = true;
         }
@@ -93,23 +103,39 @@ namespace Quik.OpenGL
             QMat4.Orthographic(out QMat4 matrix, view);
 
             GL.UseProgram(program);
-            GL.Uniform1(iMaxZ, queue.ZDepth+1);
+            GL.Uniform1(fMaxZ, (float)(queue.ZDepth+1));
             GL.UniformMatrix4(m4Transforms, false, in matrix);
             GL.Uniform1(fSdfThreshold, 0.0f);
-            GL.Uniform1(txTexture, 0);
+            GL.Uniform1(tx2d, 0);
             GL.Enable(GL_BLEND);
             GL.BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
             foreach (DrawCall call in queue)
             {
+                GL.Viewport(
+                    (int)call.Bounds.Left,
+                    (int)(view.Bottom - call.Bounds.Bottom),
+                    (int)call.Bounds.Right,
+                    (int)(view.Bottom - call.Bounds.Top));
                 GL.ActiveTexture(GL_TEXTURE0);
                 GL.BindTexture(GL_TEXTURE_2D, 0);
                 if (call.Texture != null)
                 {
-                    // TODO: actually use textures?
-                    GL.Uniform1(iEnableTexture, 1);
-                    GL.Uniform1(iEnableSdf, call.Texture.SignedDistanceField ? 1 : 0);
+                    GL.Uniform1(iEnableSdf, call.Texture.IsSdf ? 1 : 0);
                     GL.Uniform1(iAlphaDiscard, 1);
+
+                    if (call.Texture.Depth > 1)
+                    {
+                        GL.Uniform1(iEnableTexture, 3);
+                        GL.ActiveTexture(GL_TEXTURE1);
+                        GL.BindTexture(GL_TEXTURE_2D_ARRAY, textures.GetTexture(call.Texture));
+                    }
+                    else
+                    {
+                        GL.Uniform1(iEnableTexture, 2);
+                        GL.ActiveTexture(GL_TEXTURE0);
+                        GL.BindTexture(GL_TEXTURE_2D, textures.GetTexture(call.Texture));
+                    }
                 }
                 else
                 {
@@ -254,13 +280,15 @@ namespace Quik.OpenGL
                 GL.BufferData(GL_ARRAY_BUFFER, QuikVertex.Stride * Queue.VertexCount, Queue.VertexArray, GL_STREAM_DRAW);
 
                 GL.VertexAttribPointer(driver.v2Position, 2, GL_FLOAT, false, QuikVertex.Stride, QuikVertex.PositionOffset);
-                GL.VertexAttribIPointer(driver.iZIndex, 1, GL_UNSIGNED_INT, QuikVertex.Stride, QuikVertex.ZIndexOffset);
+                GL.VertexAttribPointer(driver.fZIndex, 1, GL_UNSIGNED_INT, false, QuikVertex.Stride, QuikVertex.ZIndexOffset);
                 GL.VertexAttribPointer(driver.v2TexPos, 2, GL_FLOAT, false, QuikVertex.Stride, QuikVertex.TextureCoordinatesOffset);
+                GL.VertexAttribPointer(driver.fTexLayer, 1, GL_FLOAT, false, QuikVertex.Stride, QuikVertex.TextureLayerOffset);
                 GL.VertexAttribPointer(driver.v4Color, 4, GL_UNSIGNED_BYTE, true, QuikVertex.Stride, QuikVertex.ColorOffset);
                 GL.EnableVertexAttribArray(driver.v2Position);
-                GL.EnableVertexAttribArray(driver.iZIndex);
+                GL.EnableVertexAttribArray(driver.fZIndex);
                 GL.EnableVertexAttribArray(driver.v2TexPos);
                 GL.EnableVertexAttribArray(driver.v4Color);
+                GL.EnableVertexAttribArray(driver.fTexLayer);
 
                 GL.BindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
                 GL.BufferData(GL_ELEMENT_ARRAY_BUFFER, Queue.ElementCount * sizeof(int), Queue.ElementArray, GL_STREAM_DRAW);
@@ -287,4 +315,115 @@ namespace Quik.OpenGL
             }
         }
     }
+
+    internal class TextureManager : IDisposable
+    {
+        private readonly Dictionary<QImage, int> textures = new Dictionary<QImage, int>();
+        private readonly HashSet<QImage> imagesNotUsed = new HashSet<QImage>();
+        private bool isDisposed = false;
+
+        public void BeginFrame()
+        {
+            if (imagesNotUsed.Count > 0)
+            {
+                foreach (QImage image in imagesNotUsed)
+                {
+                    GL.DeleteTexture(textures[image]);
+                }
+
+                imagesNotUsed.Clear();
+            }
+
+            foreach (QImage image in textures.Keys)
+            {
+                imagesNotUsed.Add(image);
+            }
+        }
+
+        public int GetTexture(QImage image)
+        {
+            if (textures.TryGetValue(image, out int texture))
+            {
+                return texture;
+            }
+
+            if (image.Depth > 1)
+            {
+                texture = UploadTexture3d(image);
+            }
+            else
+            {
+                texture = UploadTexture2d(image);
+            }
+           
+            return textures[image] = texture;
+        }
+
+        public int UploadTexture3d(QImage image3d)
+        {
+            int texture = GL.GenTexture();
+
+            GL.BindTexture(GL_TEXTURE_2D_ARRAY, texture);
+
+            image3d.LockBits3d(out QImageLock lck, QImageLockOptions.Default);
+                GL.TexImage3D(GL_TEXTURE_2D_ARRAY, 0, GL_RGBA, lck.Width, lck.Height, lck.Depth, 0, s_InternalFormat[lck.Format], s_PixelType[lck.Format], lck.ImagePtr);
+            image3d.UnlockBits();
+
+            GL.TexParameter(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+            GL.TexParameter(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+            return texture;
+        }
+
+        public int UploadTexture2d(QImage image2d)
+        {
+            int texture = GL.GenTexture();
+
+            GL.BindTexture(GL_TEXTURE_2D, texture);
+
+            image2d.LockBits2d(out QImageLock lck, QImageLockOptions.Default);
+            GL.TexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, lck.Width, lck.Height, 0, s_InternalFormat[lck.Format], s_PixelType[lck.Format], lck.ImagePtr);
+            image2d.UnlockBits();
+
+            GL.TexParameter(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+            GL.TexParameter(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+            return texture;
+        }
+
+        public void Dispose()
+        {
+            if (isDisposed)
+                return;
+
+            isDisposed = true;
+
+            int[] ids = textures.Values.ToArray();
+            GL.DeleteTextures(ids);
+        }
+
+        private static readonly Dictionary<QImageFormat, GLEnum> s_InternalFormat = new Dictionary<QImageFormat, GLEnum>()
+        {
+            [QImageFormat.AlphaF] = GL_ALPHA,
+            [QImageFormat.AlphaU8] = GL_ALPHA,
+            [QImageFormat.RedF] = GL_RED,
+            [QImageFormat.RedU8] = GL_RED,
+            [QImageFormat.RgbF] = GL_RGB,
+            [QImageFormat.RgbU8] = GL_RGB,
+            [QImageFormat.RgbaU8] = GL_RGBA,
+            [QImageFormat.RgbaF] = GL_RGBA,
+        };
+
+        private static readonly Dictionary<QImageFormat, GLEnum> s_PixelType = new Dictionary<QImageFormat, GLEnum>()
+        {
+            [QImageFormat.AlphaF] = GL_FLOAT,
+            [QImageFormat.RedF] = GL_FLOAT,
+            [QImageFormat.RgbF] = GL_FLOAT,
+            [QImageFormat.RgbaF] = GL_FLOAT,
+            [QImageFormat.AlphaU8] = GL_UNSIGNED_BYTE,
+            [QImageFormat.RedU8] = GL_UNSIGNED_BYTE,
+            [QImageFormat.RgbU8] = GL_UNSIGNED_BYTE,
+            [QImageFormat.RgbaU8] = GL_UNSIGNED_BYTE,
+        };
+    }
 }

Quik/OpenGL/GLEnum.cs

@@ -50,6 +50,7 @@ namespace Quik.OpenGL
         GL_TEXTURE6 = GL_TEXTURE0 + 6,
 
         GL_TEXTURE_2D = 0x0DE1,
+        GL_TEXTURE_2D_ARRAY = 0x8C1A,
         GL_UNPACK_ALIGNMENT = 0x0CF5,
 
         GL_TEXTURE_MAG_FILTER = 0x2800,

Quik/QuikGeometry.cs

@@ -12,7 +12,7 @@ namespace Quik
     {
         public float X;
         public float Y;
-
+        
         public float Magnitude => MathF.Sqrt(X * X + Y * Y);
 
         public QVec2(float x, float y)
@@ -92,6 +92,10 @@ namespace Quik
         {
             return $"({X}; {Y})";
         }
+
+        public static readonly QVec2 Zero = new QVec2(0, 0);
+        public static readonly QVec2 UnitX = new QVec2(1, 0);
+        public static readonly QVec2 UnitY = new QVec2(0, 1);
     }
 
     /// <summary>

Quik/res/gl21.frag

@@ -2,16 +2,34 @@
  * QUIK: User Interface Kit
  * Copyright (C) 2023 Halit Utku Maden, et al.
  */
-#version 120
+#version 130
 
-varying vec2        fv2TexPos;
-varying vec4        fv4Color;
+in vec2        fv2TexPos;
+in vec4        fv4Color;
+in float       ffTexLayer;
 
-uniform int         iEnableSdf;
-uniform int         iEnableTexture;
-uniform int         iAlphaDiscard;
-uniform float       fSdfThreshold;
-uniform sampler2D   txTexture;
+out vec4 fragColor;
+
+uniform int            iEnableSdf;
+uniform int            iEnableTexture;
+uniform int            iAlphaDiscard;
+uniform float          fSdfThreshold;
+uniform sampler2D      tx2d;
+uniform sampler2DArray tx2dArray;
+
+const float fAlphaThreshold = 0.01;
+
+vec4 getTexture()
+{
+    if (iEnableTexture == 3)
+    {
+        return texture(tx2dArray, vec3(fv2TexPos, ffTexLayer));
+    }
+    else
+    {
+        return texture(tx2d, fv2TexPos);
+    }
+}
 
 void main(void)
 {
@@ -19,16 +37,19 @@ void main(void)
 
     if (iEnableTexture != 0)
     {
-        vec4 value = texture2D(txTexture, fv2TexPos);
+        vec4 value = getTexture();
 
         if (iEnableSdf != 0)
         {
             float a = max(value.r, value.a);
 
-            value = (a >= fSdfThreshold) ? vec4(1,1,1,1) : vec4(0,0,0,0);
+            value = 
+                (a >= fSdfThreshold) ?
+                    vec4(1.0,1.0,1.0,1.0) :
+                    vec4(0.0,0.0,0.0,0.0);
         }
 
-        if (iAlphaDiscard != 0 && value.a == 0.0)
+        if (iAlphaDiscard != 0 && value.a <= fAlphaThreshold)
         {
             discard;
         }
@@ -36,5 +57,5 @@ void main(void)
         albedo = albedo * value;
     }
 
-    gl_FragColor = albedo;
+    fragColor = albedo;
 }

Quik/res/gl21.vert

@@ -2,24 +2,34 @@
  * QUIK: User Interface Kit
  * Copyright (C) 2023 Halit Utku Maden, et al.
  */
-#version 120
+#version 130
 
-attribute vec2  v2Position;     /**< The vertex position.*/
-attribute int   iZIndex;        /**< The z index. */
-attribute vec2  v2TexPos;       /**< The texture coorindates. */
-attribute vec4  v4Color;        /**< The vertex color. */
+in vec2  v2Position;     /**< The vertex position.*/
+in float fZIndex;        /**< The z index. */
+in vec2  v2TexPos;       /**< The texture coorindates. */
+in float fTexLayer;      /**< The texture layer for 3D textures. */
+in vec4  v4Color;        /**< The vertex color. */
 
-varying vec2    fv2TexPos;
-varying vec4    fv4Color;
+out vec2    fv2TexPos;
+out float   ffTexLayer;
+out vec4    fv4Color;
 
 uniform mat4        m4Transforms;   /**< The view matrix. */
-uniform int         iMaxZ;          /**< Highest Z coordinate. */
+uniform float       fMaxZ;          /**< Highest Z coordinate. */
+
+const mat4 m4BaseTransforms = mat4(
+    vec4( 2.0,  0.0,  0.0,  0.0),
+    vec4( 0.0, -2.0,  0.0,  0.0),
+    vec4( 0.0,  0.0,  1.0,  0.0),
+    vec4(-1.0,  1.0,  0.0,  1.0)
+);
 
 void main(void)
 {
-    vec4 v = vec4(v2Position, float(iZIndex)/float(iMaxZ), 1);
-    gl_Position = v * m4Transforms;
+    vec4 v      = vec4(v2Position, fZIndex/fMaxZ, 1);
+    gl_Position = m4Transforms * v;
 
     fv2TexPos = v2TexPos;
     fv4Color = v4Color;
-}
+    ffTexLayer = fTexLayer;
+}