From e3c37c6511bfef707e71543c02bd3e23894a9128 Mon Sep 17 00:00:00 2001
From: Natty <31473117+493msi@users.noreply.github.com>
Date: Fri, 15 Apr 2022 01:56:39 +0200
Subject: [PATCH] Fixed linear gradient rendering in the demo

---
 UPDATE_NOTES.md                               |  3 ++
 .../main/kotlin/org/plutoengine/Versions.kt   |  2 +-
 .../default/shaders/FragmentFontShader.glsl   | 36 +++++++++++++------
 .../main/java/org/plutoengine/demo/Main.java  |  2 +-
 libra                                         |  2 +-
 5 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/UPDATE_NOTES.md b/UPDATE_NOTES.md
index f2d2407..2da776c 100755
--- a/UPDATE_NOTES.md
+++ b/UPDATE_NOTES.md
@@ -1,3 +1,6 @@
+## 22.1.0.0-alpha.1
+* `plutoengine-demos/basic-application` Made the gradient in the fragment font shader rotatable
+
 ## 22.1.0.0-alpha.0
 * `[PlutoMesher]` **Partial rewrite**
   * *Removed* `VecArray`
diff --git a/buildSrc/src/main/kotlin/org/plutoengine/Versions.kt b/buildSrc/src/main/kotlin/org/plutoengine/Versions.kt
index cf6818c..9ccb0a0 100755
--- a/buildSrc/src/main/kotlin/org/plutoengine/Versions.kt
+++ b/buildSrc/src/main/kotlin/org/plutoengine/Versions.kt
@@ -23,7 +23,7 @@ object Versions {
 
     const val isPrerelease = true
     const val prereleaseName = "alpha"
-    const val prerealeaseUpdate = 0
+    const val prerealeaseUpdate = 1
 
     val versionFull =
         if (isPrerelease)
diff --git a/engine-demo/basic-application/mods/tefek.plutogui/default/shaders/FragmentFontShader.glsl b/engine-demo/basic-application/mods/tefek.plutogui/default/shaders/FragmentFontShader.glsl
index 9e59eee..b71866c 100755
--- a/engine-demo/basic-application/mods/tefek.plutogui/default/shaders/FragmentFontShader.glsl
+++ b/engine-demo/basic-application/mods/tefek.plutogui/default/shaders/FragmentFontShader.glsl
@@ -23,22 +23,38 @@ vec4 solidColor(void)
     return paintColor;
 }
 
+vec4 gammaMix(vec4 lCol, vec4 rCol, float ratio)
+{
+    float gamma = 2.2;
+    float one_over_gamma = 1 / gamma;
+
+    vec4 ilCol = vec4(pow(lCol.r, gamma), pow(lCol.g, gamma), pow(lCol.b, gamma), lCol.a);
+    vec4 irCol = vec4(pow(rCol.r, gamma), pow(rCol.g, gamma), pow(rCol.b, gamma), rCol.a);
+
+    vec4 fCol = mix(ilCol, irCol, ratio);
+
+    return vec4(pow(fCol.r, one_over_gamma), pow(fCol.g, one_over_gamma), pow(fCol.b, one_over_gamma), fCol.a);
+}
+
 vec4 gradientColor(void)
 {
-    float par = smoothstep(paintGradientEnds[0].x, paintGradientEnds[1].x, paintUVCoordinates.x) * (paintGradientStopCount - 1);
+    float angle = atan(-paintGradientEnds[1].y + paintGradientEnds[0].y, paintGradientEnds[1].x - paintGradientEnds[0].x);
+    float rotatedStartX = paintGradientEnds[0].x * cos(angle) - paintGradientEnds[0].y * sin(angle);
+    float rotatedEndX = paintGradientEnds[1].x * cos(angle) - paintGradientEnds[1].y * sin(angle);
+    float d = rotatedEndX - rotatedStartX;
 
-    float nPar = clamp(par, 0, float(paintGradientStopCount - 1)) + paintGradientPositions[0] * 0.000001;
-    vec4 lCol = paintGradientColors[int(floor(nPar))];
-    vec4 rCol = paintGradientColors[int(ceil(nPar))];
+    float pX = paintUVCoordinates.x * cos(angle) - paintUVCoordinates.y * sin(angle);
 
-    float gamma = 0.45;
+    float mr = smoothstep(rotatedStartX + paintGradientPositions[0] * d, rotatedStartX + paintGradientPositions[1] * d, pX);
+    vec4 col = gammaMix(paintGradientColors[0], paintGradientColors[1], mr);
 
-    vec4 ilCol = vec4(pow(lCol.r, 1 / gamma), pow(lCol.g, 1 / gamma), pow(lCol.b, 1 / gamma), lCol.a);
-    vec4 irCol = vec4(pow(rCol.r, 1 / gamma), pow(rCol.g, 1 / gamma), pow(rCol.b, 1 / gamma), rCol.a);
+    for (int i = 1; i < paintGradientStopCount - 1; i++)
+    {
+        mr = smoothstep(rotatedStartX + paintGradientPositions[i] * d, rotatedStartX + paintGradientPositions[i + 1] * d, pX);
+        col = gammaMix(col, paintGradientColors[i + 1], mr);
+    }
 
-    vec4 fCol = mix(ilCol, irCol, fract(nPar));
-
-    return vec4(pow(fCol.r, gamma), pow(fCol.g, gamma), pow(fCol.b, gamma), fCol.a);
+    return col;
 }
 
 void main(void)
diff --git a/engine-demo/basic-application/src/main/java/org/plutoengine/demo/Main.java b/engine-demo/basic-application/src/main/java/org/plutoengine/demo/Main.java
index 50409a0..0e9c289 100755
--- a/engine-demo/basic-application/src/main/java/org/plutoengine/demo/Main.java
+++ b/engine-demo/basic-application/src/main/java/org/plutoengine/demo/Main.java
@@ -65,7 +65,7 @@ public class Main extends PlutoApplication
         var watermarkStyle = new TextStyleOptions(20.0f);
         watermarkStyle.setHorizontalAlign(TextStyleOptions.TextAlign.CENTER);
         watermarkStyle.setPaint(LiPaint.solidColor(Color.from(0x4f000000, EnumColorFormat.CF_INT_ARGB)));
-        ImmediateFontRenderer.drawString(this.display.getWidth() / 2.0f, 5, "PlutoEngine demo build licensed the MIT license...", BasicApplicationDemoMod.font, watermarkStyle);
+        ImmediateFontRenderer.drawString(this.display.getWidth() / 2.0f, 5, "PlutoEngine demo build licensed under the MIT license", BasicApplicationDemoMod.font, watermarkStyle);
 
         RectangleRenderer2D.draw()
                            .at(this.display.getWidth() / 2.0f - 150, this.display.getHeight() / 2.0f - 246, 300, 300)
diff --git a/libra b/libra
index 443ab09..3e0521b 160000
--- a/libra
+++ b/libra
@@ -1 +1 @@
-Subproject commit 443ab09e71c4ff08184167646fa8b2fe3465986a
+Subproject commit 3e0521b1b072f3f87f3ac2131c6849b0624a370f