From 816272e46b372d32650725ac2380fb8dcc1000a5 Mon Sep 17 00:00:00 2001
From: Mike Welsh <mwelsh@gmail.com>
Date: Wed, 23 Sep 2020 16:35:10 -0700
Subject: [PATCH] webgl: Bump max gradient count to 15

---
 render/webgl/shaders/gradient.frag | 29 +++++++++++++++++++++++++----
 render/webgl/src/lib.rs            | 12 +++++++-----
 2 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/render/webgl/shaders/gradient.frag b/render/webgl/shaders/gradient.frag
index 53177f87e..f25565227 100644
--- a/render/webgl/shaders/gradient.frag
+++ b/render/webgl/shaders/gradient.frag
@@ -8,8 +8,8 @@ uniform vec4 add_color;
 uniform mat3 u_matrix;
 
 uniform int u_gradient_type;
-uniform float u_ratios[8];
-uniform vec4 u_colors[8];
+uniform float u_ratios[15];
+uniform vec4 u_colors[15];
 uniform int u_num_colors;
 uniform int u_repeat_mode;
 uniform float u_focal_point;
@@ -95,14 +95,35 @@ void main() {
     } else if( t <= u_ratios[7] ) {
         a = (t - u_ratios[6]) / (u_ratios[7] - u_ratios[6]);
         color = mix(u_colors[6], u_colors[7], a);
+    } else if( t <= u_ratios[8] ) {
+        a = (t - u_ratios[7]) / (u_ratios[8] - u_ratios[7]);
+        color = mix(u_colors[7], u_colors[8], a);
+    } else if( t <= u_ratios[9] ) {
+        a = (t - u_ratios[8]) / (u_ratios[9] - u_ratios[8]);
+        color = mix(u_colors[8], u_colors[9], a);
+    } else if( t <= u_ratios[10] ) {
+        a = (t - u_ratios[9]) / (u_ratios[10] - u_ratios[9]);
+        color = mix(u_colors[9], u_colors[10], a);
+    } else if( t <= u_ratios[11] ) {
+        a = (t - u_ratios[10]) / (u_ratios[11] - u_ratios[10]);
+        color = mix(u_colors[10], u_colors[11], a);
+    } else if( t <= u_ratios[12] ) {
+        a = (t - u_ratios[11]) / (u_ratios[12] - u_ratios[11]);
+        color = mix(u_colors[11], u_colors[12], a);
+    } else if( t <= u_ratios[13] ) {
+        a = (t - u_ratios[12]) / (u_ratios[13] - u_ratios[12]);
+        color = mix(u_colors[12], u_colors[13], a);
+    } else if( t <= u_ratios[14] ) {
+        a = (t - u_ratios[13]) / (u_ratios[14] - u_ratios[13]);
+        color = mix(u_colors[13], u_colors[14], a);
     } else {
-        color = u_colors[7];
+        color = u_colors[14];
     }
 
     if( u_interpolation != 0 ) {
         color = vec4(linear_to_srgb(vec3(color)), color.a);
     }
 
-    gl_FragColor = mult_color * color + add_color;;
+    gl_FragColor = mult_color * color + add_color;
 }
 
diff --git a/render/webgl/src/lib.rs b/render/webgl/src/lib.rs
index d28be33b4..7821c002f 100644
--- a/render/webgl/src/lib.rs
+++ b/render/webgl/src/lib.rs
@@ -66,6 +66,8 @@ pub struct WebGlRenderBackend {
     view_matrix: [[f32; 4]; 4],
 }
 
+const MAX_GRADIENT_COLORS: usize = 15;
+
 impl WebGlRenderBackend {
     pub fn new(canvas: &HtmlCanvasElement) -> Result<Self, Error> {
         // Create WebGL context.
@@ -479,9 +481,9 @@ impl WebGlRenderBackend {
                     },
                 ),
                 TessDrawType::Gradient(gradient) => {
-                    let mut ratios = [0.0; 8];
-                    let mut colors = [[0.0; 4]; 8];
-                    let num_colors = gradient.num_colors as usize;
+                    let mut ratios = [0.0; MAX_GRADIENT_COLORS];
+                    let mut colors = [[0.0; 4]; MAX_GRADIENT_COLORS];
+                    let num_colors = (gradient.num_colors as usize).min(MAX_GRADIENT_COLORS);
                     ratios[..num_colors].copy_from_slice(&gradient.ratios[..num_colors]);
                     colors[..num_colors].copy_from_slice(&gradient.colors[..num_colors]);
                     // Convert to linear color space if this is a linear-interpolated gradient.
@@ -1244,8 +1246,8 @@ struct Texture {
 struct Gradient {
     matrix: [[f32; 3]; 3],
     gradient_type: i32,
-    ratios: [f32; 8],
-    colors: [[f32; 4]; 8],
+    ratios: [f32; MAX_GRADIENT_COLORS],
+    colors: [[f32; 4]; MAX_GRADIENT_COLORS],
     num_colors: u32,
     repeat_mode: i32,
     focal_point: f32,