Update articles to use glsl over c as code highlighter for glsl

Author: deccer

blog/2024/2024-10-17-glsl-development-made-shrimple/index.md

@@ -61,7 +61,7 @@ Writing the same structure definitions for buffers in both C or C++ and GLSL is
 is to abuse macros. It also requires shading language includes.
 
 The first step is to write a "shared header" of common definitions that can be understood by both GLSL and C++. This file is split into sections that are only compiled in one language or the other:
-```c
+```glsl
 #ifndef COMMON_H
 #define COMMON_H
 
@@ -83,7 +83,7 @@ The first step is to write a "shared header" of common definitions that can be u
 ```
 
 The second step is to put structure definitions in a file that both languages understand. This can be a separate header, or in the body of the shader itself. For an example of the latter:
-```c
+```glsl
 // Common section
 #include "Common.h"
 

blog/2024/2024-10-30-generating-phase-functions-luts-with-mieplot/index.md

@@ -161,7 +161,7 @@ glm::vec3 MapToUnitSphere(glm::vec2 uv)
 
 I suggest testing your normalization by plugging in a known-good analytical phase function like Henyey-Greenstein or Schlick's. These integrate to 1 and so don't require hacky normalization:
 
-```cpp
+```glsl
 float phaseHG(float g, float cosTheta)
 {
     return (1.0 - g * g) / (4.0 * M_PI * pow(1.0 + g * g - 2.0 * g * cosTheta, 1.5));
@@ -180,7 +180,7 @@ After normalizing the data, we can put it into a 1D texture.
 
 We only need to keep in mind that the our LUT-based phase function is parameterized by theta (unlike HG and Schlick above). Here's how you might access it in GLSL:
 
-```c
+```glsl
 layout(binding = 0) uniform sampler1D s_phaseFunction;
 
 vec3 phaseLut(float cosTheta)