From 431e3ddf8dfb68e2c5449f2f7cf49aa83be289a8 Mon Sep 17 00:00:00 2001
From: Igor Gutorov <igootorov@gmail.com>
Date: Tue, 20 Mar 2018 21:00:46 +0200
Subject: [PATCH] Simplify GetTexParameter

---
 components/canvas/webgl_thread.rs             | 17 +------
 components/canvas_traits/webgl.rs             |  2 +-
 .../script/dom/webglrenderingcontext.rs       | 50 +++++++++++--------
 3 files changed, 32 insertions(+), 37 deletions(-)

diff --git a/components/canvas/webgl_thread.rs b/components/canvas/webgl_thread.rs
index bfb6c7ab5cb..e4d807b01d6 100644
--- a/components/canvas/webgl_thread.rs
+++ b/components/canvas/webgl_thread.rs
@@ -1066,21 +1066,8 @@ impl WebGLImpl {
     fn get_tex_parameter(gl: &gl::Gl,
                        target: u32,
                        pname: u32,
-                       chan: WebGLSender<WebGLResult<WebGLParameter>> ) {
-        let result = match pname {
-            gl::TEXTURE_MAG_FILTER |
-            gl::TEXTURE_MIN_FILTER |
-            gl::TEXTURE_WRAP_S |
-            gl::TEXTURE_WRAP_T => {
-                let parameter = gl.get_tex_parameter_iv(target, pname);
-                if parameter == 0 {
-                    Ok(WebGLParameter::Invalid)
-                } else {
-                    Ok(WebGLParameter::Int(parameter))
-                }
-            }
-            _ => Err(WebGLError::InvalidEnum)
-        };
+                       chan: WebGLSender<i32> ) {
+        let result = gl.get_tex_parameter_iv(target, pname);
         chan.send(result).unwrap();
     }
 
diff --git a/components/canvas_traits/webgl.rs b/components/canvas_traits/webgl.rs
index 70aeb40ab06..ac0e5a17b99 100644
--- a/components/canvas_traits/webgl.rs
+++ b/components/canvas_traits/webgl.rs
@@ -207,7 +207,7 @@ pub enum WebGLCommand {
     GetBufferParameter(u32, u32, WebGLSender<WebGLResult<WebGLParameter>>),
     GetExtensions(WebGLSender<String>),
     GetParameter(u32, WebGLSender<WebGLResult<WebGLParameter>>),
-    GetTexParameter(u32, u32, WebGLSender<WebGLResult<WebGLParameter>>),
+    GetTexParameter(u32, u32, WebGLSender<i32>),
     GetProgramParameter(WebGLProgramId, u32, WebGLSender<WebGLResult<WebGLParameter>>),
     GetShaderParameter(WebGLShaderId, u32, WebGLSender<WebGLResult<WebGLParameter>>),
     GetShaderPrecisionFormat(u32, u32, WebGLSender<WebGLResult<(i32, i32, i32)>>),
diff --git a/components/script/dom/webglrenderingcontext.rs b/components/script/dom/webglrenderingcontext.rs
index 0145d84ffd8..c6443ecfd29 100644
--- a/components/script/dom/webglrenderingcontext.rs
+++ b/components/script/dom/webglrenderingcontext.rs
@@ -1342,31 +1342,39 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     #[allow(unsafe_code)]
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.8
     unsafe fn GetTexParameter(&self, _cx: *mut JSContext, target: u32, pname: u32) -> JSVal {
-        let texture = match target {
+        let target_matches = match target {
             constants::TEXTURE_2D |
-            constants::TEXTURE_CUBE_MAP => self.bound_texture(target),
+            constants::TEXTURE_CUBE_MAP => true,
+            _ => false,
+        };
+
+        let pname_matches = match pname {
+            constants::TEXTURE_MAG_FILTER |
+            constants::TEXTURE_MIN_FILTER |
+            constants::TEXTURE_WRAP_S |
+            constants::TEXTURE_WRAP_T => true,
+            _ => false,
+        };
+
+        if !target_matches || !pname_matches {
+            self.webgl_error(InvalidEnum);
+            return NullValue();
+        }
+
+        if self.bound_texture(target).is_none() {
+            self.webgl_error(InvalidOperation);
+            return NullValue();
+        }
+
+        let (sender, receiver) = webgl_channel().unwrap();
+        self.send_command(WebGLCommand::GetTexParameter(target, pname, sender));
+
+        match receiver.recv().unwrap() {
+            value if value != 0 => Int32Value(value),
             _ => {
                 self.webgl_error(InvalidEnum);
-                return NullValue();
+                NullValue()
             }
-        };
-        if texture.is_some() {
-            let (sender, receiver) = webgl_channel().unwrap();
-            self.send_command(WebGLCommand::GetTexParameter(target, pname, sender));
-            match handle_potential_webgl_error!(self, receiver.recv().unwrap(), WebGLParameter::Invalid) {
-                WebGLParameter::Int(val) => Int32Value(val),
-                WebGLParameter::Bool(_) => panic!("Texture parameter should not be bool"),
-                WebGLParameter::Float(_) => panic!("Texture parameter should not be float"),
-                WebGLParameter::FloatArray(_) => panic!("Texture parameter should not be float array"),
-                WebGLParameter::String(_) => panic!("Texture parameter should not be string"),
-                WebGLParameter::Invalid => {
-                    self.webgl_error(InvalidEnum);
-                    NullValue()
-                }
-            }
-        } else {
-            self.webgl_error(InvalidOperation);
-            NullValue()
         }
     }