GPU: move filtered sampler to fragui.glsl, delete fragui_bicubic.glsl, add documentation

runelite-client/src/main/java/net/runelite/client/plugins/gpu/GpuPlugin.java

@@ -146,10 +146,6 @@ public class GpuPlugin extends Plugin implements DrawCallbacks
 	private int glUiVertexShader;
 	private int glUiFragmentShader;
 
-	private int glUiBicubicProgram;
-	private int glUiBicubicVertexShader;
-	private int glUiBicubicFragmentShader;
-
 	private int vaoUiHandle;
 	private int vboUiHandle;
 
@@ -223,7 +219,7 @@ public class GpuPlugin extends Plugin implements DrawCallbacks
 	private int uniProjectionMatrix;
 	private int uniBrightness;
 	private int uniTex;
-	private int uniTexBicubic;
+	private int uniTexSamplingMode;
 	private int uniTextures;
 	private int uniTextureOffsets;
 	private int uniBlockSmall;
@@ -510,15 +506,6 @@ public class GpuPlugin extends Plugin implements DrawCallbacks
 			null,
 			inputStreamToString(getClass().getResourceAsStream("fragui.glsl")));
 
-		glUiBicubicProgram = gl.glCreateProgram();
-		glUiBicubicVertexShader = gl.glCreateShader(gl.GL_VERTEX_SHADER);
-		glUiBicubicFragmentShader = gl.glCreateShader(gl.GL_FRAGMENT_SHADER);
-		GLUtil.loadShaders(gl, glUiBicubicProgram, glUiBicubicVertexShader, -1, glUiBicubicFragmentShader,
-		inputStreamToString(getClass().getResourceAsStream("vertui.glsl")),
-		null,
-		inputStreamToString(getClass().getResourceAsStream("fragui_bicubic.glsl")));
-
-
 		initUniforms();
 	}
 
@@ -533,7 +520,7 @@ public class GpuPlugin extends Plugin implements DrawCallbacks
 		uniDrawDistance = gl.glGetUniformLocation(glProgram, "drawDistance");
 
 		uniTex = gl.glGetUniformLocation(glUiProgram, "tex");
-		uniTexBicubic = gl.glGetUniformLocation(glUiBicubicProgram, "tex");
+		uniTexSamplingMode = gl.glGetUniformLocation(glUiProgram, "samplingMode");
 		uniTextures = gl.glGetUniformLocation(glProgram, "textures");
 		uniTextureOffsets = gl.glGetUniformLocation(glProgram, "textureOffsets");
 
@@ -586,9 +573,6 @@ public class GpuPlugin extends Plugin implements DrawCallbacks
 
 		gl.glDeleteProgram(glUiProgram);
 		glUiProgram = -1;
-
-		gl.glDeleteProgram(glUiBicubicProgram);
-		glUiBicubicProgram = -1;
 	}
 
 	private void initVao()
@@ -1182,18 +1166,10 @@ public class GpuPlugin extends Plugin implements DrawCallbacks
 			glDpiAwareViewport(0, 0, canvasWidth, canvasHeight);
 		}
 
-		if (client.isStretchedEnabled() && config.uiScalingMode() == UIScalingMode.CATMULL_ROM)
+		// Use the texture bound in the first pass
-		{
+		gl.glUseProgram(glUiProgram);
-			// Use the texture bound in the first pass
+		gl.glUniform1i(uniTex, 0);
-			gl.glUseProgram(glUiBicubicProgram);
+		gl.glUniform1i(uniTexSamplingMode, config.uiScalingMode().getMode());
-			gl.glUniform1i(uniTexBicubic, 0);
-		}
-		else
-		{
-			// Use the texture bound in the first pass
-			gl.glUseProgram(glUiProgram);
-			gl.glUniform1i(uniTex, 0);
-		}
 
 		// Set the sampling function used when stretching the UI.
 		// This is probably better done with sampler objects instead of texture parameters, but this is easier and likely more portable.

runelite-client/src/main/java/net/runelite/client/plugins/gpu/config/UIScalingMode.java

@@ -31,11 +31,12 @@ import lombok.RequiredArgsConstructor;
 @RequiredArgsConstructor
 public enum UIScalingMode
 {
-	NEAREST("Nearest Neighbor"),
+	NEAREST("Nearest Neighbor", 0),
-	LINEAR("Bilinear"),
+	LINEAR("Bilinear", 0),
-	CATMULL_ROM("Bicubic (Catmull-Rom)");
+	CATMULL_ROM("Bicubic (Catmull-Rom)", 1);
 
 	private final String name;
+	private final int mode;
 
 	@Override
 	public String toString()

runelite-client/src/main/resources/net/runelite/client/plugins/gpu/fragui.glsl

@@ -26,11 +26,93 @@
 
 uniform sampler2D tex;
 
+// Modes:
+// 0 - default sampling, either GL_LINEAR or GL_NEAREST depending on texture attributes
+// 1 - bicubic sampling with Catmull-Rom spline values
+uniform int samplingMode;
+
 in vec2 TexCoord;
 
 out vec4 FragColor;
 
-void main() {
+// Cubic filter with Catmull-Rom parameters
-  vec4 c = texture(tex, TexCoord);
+float catmull_rom(float x)
-  FragColor = c;
+{
+    /* A generalized cubic filter as described by Mitchell and Netravali is defined by the piecewise equation:
+     * if abs(x) < 1
+     *  y = 1/6 * ( (12 - 9b - 6c) * abs(x)^3 + (-18 + 12b + 6c) * abs(x)^2 + (6 - 2b) )
+     * if abs(x) >= 1 and < 2
+     *  y = 1/6 * ( (-1b - 6c) * abs(x)^3 + (6b + 30c) * abs(x)^2 + (-12b - 48c) * abs(x) + (8b + 24c) )
+     * otherwise
+     *  y = 0
+     * Generally favorable results in image upscaling are given by the values b = 0 and c = 0.5.
+     * This is known as the Catmull-Rom filter.
+     * Placing these values into the piecewise equations gives us a more compact representation of:
+     *  y = 1.5 * abs(x)^3 - 2.5 * abs(x)^2 + 1                 // abs(x) < 1
+     *  y = -0.5 * abs(x)^3 + 2.5 * abs(x)^2 - 4 * abs(x) + 2   // 1 <= abs(x) < 2
+     */
+
+    float t = abs(x);       // absolute value of the x coordinate
+    float t2 = t * t;       // t squared
+    float t3 = t * t * t;   // t cubed
+
+    if (t < 1)
+        return 1.5 * t3 - 2.5 * t2 + 1;
+    else if (t < 2)
+        return -0.5 * t3 + 2.5 * t2 - 4 * t + 2;
+    else
+        return 0;
+}
+
+// Samples a texture using a 4x4 filtering kernel.
+vec4 textureFiltered(sampler2D sampler, vec2 texCoords){
+    vec2 texSize = textureSize(tex, 0);
+    vec2 texelSize = 1.0 / texSize;
+    texCoords *= texSize;
+    texCoords -= 0.5;
+
+    vec4 nSum = vec4( 0.0, 0.0, 0.0, 0.0 );
+    vec4 nDenom = vec4( 0.0, 0.0, 0.0, 0.0 );
+
+    ivec2 texelCoords = ivec2(floor(texCoords));
+    vec2 coordFract = fract(texCoords);
+
+    if (samplingMode == 1)
+    {
+        for (int m = -1; m <= 2; m++)
+        {
+            for (int n = -1; n <= 2; n++)
+            {
+                // get the raw texel, bypassing any other filters
+                vec4 vecData = texelFetch(sampler, texelCoords + ivec2(m, n), 0);
+
+                // calculate weights based on distance of the current texel offset from the sub-texel position of the sampling location
+                float cx = catmull_rom( m - coordFract.x );
+                float cy = catmull_rom( n - coordFract.y );
+
+                // build the weighted average
+                nSum += vecData * cx * cy;
+                nDenom += cx * cy;
+            }
+        }
+    }
+    else
+    {
+        // Undefined sampling mode, fall back to default sampler
+        return texture(sampler, texCoords);
+    }
+
+    // calculate and return the weighted average
+    return nSum / nDenom;
+}
+
+void main() {
+    vec4 c;
+
+    if (samplingMode == 0)
+        c = texture(tex, TexCoord);
+    else
+        c = textureFiltered(tex, TexCoord);
+
+    FragColor = c;
 }

runelite-client/src/main/resources/net/runelite/client/plugins/gpu/fragui_bicubic.glsl

@@ -1,98 +0,0 @@
-/*
- * Copyright (c) 2019 logarrhytmic <https://github.com/logarrhythmic>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice, this
- *    list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- *    this list of conditions and the following disclaimer in the documentation
- *    and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
- * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
- * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-#version 330
-
-uniform sampler2D tex;
-
-in vec2 TexCoord;
-
-out vec4 FragColor;
-
-float CatmullRom( float x )
-{
-    const float B = 0.0;
-    const float C = 0.5;
-
-    float f = abs(x);
-    float f2 = f * f;
-    float f3 = f * f * f;
-
-    if (f >= 2) {
-        return 0.0;
-    }
-
-    if ( f < 1.0 ) {
-        return (
-            ( 12 - 9 * B - 6 * C ) * f3 +
-            ( -18 + 12 * B + 6 *C ) * f2 +
-            ( 6 - 2 * B )
-        ) / 6.0;
-    }
-    else {
-        return (
-            ( -B - 6 * C ) * f3 +
-            ( 6 * B + 30 * C ) * f2 +
-            ( - ( 12 * B ) - 48 * C  ) * f +
-            8 * B + 24 * C
-        ) / 6.0;
-    }
-}
-
-vec4 textureBicubic(sampler2D sampler, vec2 texCoords){
-    vec2 texSize = textureSize(tex, 0);
-    vec2 texelSize = 1.0 / texSize;
-    texCoords *= texSize;
-    texCoords -= 0.5;
-
-    vec4 nSum = vec4( 0.0, 0.0, 0.0, 0.0 );
-    vec4 nDenom = vec4( 0.0, 0.0, 0.0, 0.0 );
-
-    ivec2 texelCoords = ivec2(floor(texCoords));
-    vec2 fxy = fract(texCoords);
-
-    for (int m = -1; m <= 2; m++)
-    {
-        for (int n = -1; n <= 2; n++)
-        {
-            vec4 vecData = texelFetch(
-                sampler,
-                texelCoords + ivec2(m, n),
-                0
-            );
-
-            float cx = CatmullRom( m - fxy.x );
-            float cy = CatmullRom( n - fxy.y );
-
-            nSum += vecData * cx * cy;
-            nDenom += cx * cy;
-        }
-    }
-    return nSum / nDenom;
-}
-
-void main() {
-    vec4 c = textureBicubic(tex, TexCoord);
-    FragColor = c;
-}