Move shaders into glsl and hlsl directories

Move `data/shaders` to `data/shaders/glsl`
Move `data/hlsl` to `data/shaders/hlsl`

Fix up shader paths in the cpp files to point to the new glsl location.

`data/shaders/hlsl/compile.py` still overwrites the glsl .spv files (for
now).

Issue: #723

data/shaders/glsl/displacement/base.frag

@@ -0,0 +1,26 @@
+#version 450
+
+layout (binding = 2) uniform sampler2D colorMap;
+
+layout (location = 0) in vec3 inNormal;
+layout (location = 1) in vec2 inUV;
+layout (location = 2) in vec3 inEyePos;
+layout (location = 3) in vec3 inLightVec;
+
+layout (location = 0) out vec4 outFragColor;
+
+void main()
+{
+	vec3 N = normalize(inNormal);
+	vec3 L = normalize(vec3(1.0));	
+	
+	outFragColor.rgb = texture(colorMap, inUV).rgb;
+	
+	vec3 Eye = normalize(-inEyePos);
+	vec3 Reflected = normalize(reflect(-inLightVec, inNormal)); 
+
+	vec4 IAmbient = vec4(0.0, 0.0, 0.0, 1.0);
+	vec4 IDiffuse = vec4(1.0) * max(dot(inNormal, inLightVec), 0.0);
+
+	outFragColor = vec4((IAmbient + IDiffuse) * vec4(texture(colorMap, inUV).rgb, 1.0));	
+}

data/shaders/glsl/displacement/base.vert

@@ -0,0 +1,15 @@
+#version 450
+
+layout (location = 0) in vec3 inPos;
+layout (location = 1) in vec3 inNormal;
+layout (location = 2) in vec2 inUV;
+
+layout (location = 0) out vec3 outNormal;
+layout (location = 1) out vec2 outUV;
+
+void main(void)
+{
+	gl_Position = vec4(inPos.xyz, 1.0);
+    outUV = inUV * 3.0;
+	outNormal = inNormal;
+}

data/shaders/glsl/displacement/displacement.tesc

@@ -0,0 +1,29 @@
+#version 450
+
+layout (binding = 0) uniform UBO 
+{
+	float tessLevel;
+} ubo; 
+ 
+layout (vertices = 3) out;
+ 
+layout (location = 0) in vec3 inNormal[];
+layout (location = 1) in vec2 inUV[];
+ 
+layout (location = 0) out vec3 outNormal[3];
+layout (location = 1) out vec2 outUV[3];
+ 
+void main()
+{
+	if (gl_InvocationID == 0)
+	{
+		gl_TessLevelInner[0] = ubo.tessLevel;
+		gl_TessLevelOuter[0] = ubo.tessLevel;
+		gl_TessLevelOuter[1] = ubo.tessLevel;
+		gl_TessLevelOuter[2] = ubo.tessLevel;		
+	}
+
+	gl_out[gl_InvocationID].gl_Position =  gl_in[gl_InvocationID].gl_Position;
+	outNormal[gl_InvocationID] = inNormal[gl_InvocationID];
+	outUV[gl_InvocationID] = inUV[gl_InvocationID];
+} 

data/shaders/glsl/displacement/displacement.tese

@@ -0,0 +1,36 @@
+#version 450
+
+layout (binding = 1) uniform UBO 
+{
+	mat4 projection;
+	mat4 model;
+	vec4 lightPos;
+	float tessAlpha;
+	float tessStrength;
+} ubo; 
+
+layout (binding = 2) uniform sampler2D displacementMap; 
+
+layout(triangles, equal_spacing, ccw) in;
+
+layout (location = 0) in vec3 inNormal[];
+layout (location = 1) in vec2 inUV[];
+ 
+layout (location = 0) out vec3 outNormal;
+layout (location = 1) out vec2 outUV;
+layout (location = 2) out vec3 outEyesPos;
+layout (location = 3) out vec3 outLightVec;
+
+void main()
+{
+	gl_Position = (gl_TessCoord.x * gl_in[0].gl_Position) + (gl_TessCoord.y * gl_in[1].gl_Position) + (gl_TessCoord.z * gl_in[2].gl_Position); 
+	outUV = gl_TessCoord.x * inUV[0] + gl_TessCoord.y * inUV[1] + gl_TessCoord.z * inUV[2];
+	outNormal = gl_TessCoord.x * inNormal[0] + gl_TessCoord.y * inNormal[1] + gl_TessCoord.z * inNormal[2]; 
+				
+	gl_Position.xyz += normalize(outNormal) * (max(textureLod(displacementMap, outUV.st, 0.0).a, 0.0) * ubo.tessStrength);
+				
+	outEyesPos = (gl_Position).xyz;
+	outLightVec = normalize(ubo.lightPos.xyz - outEyesPos);	
+		
+	gl_Position = ubo.projection * ubo.model * gl_Position;
+}

data/shaders/glsl/displacement/generate-spirv.bat

@@ -0,0 +1,5 @@
+glslangvalidator -V base.vert -o base.vert.spv
+glslangvalidator -V base.frag -o base.frag.spv
+glslangvalidator -V displacement.tesc -o displacement.tesc.spv
+glslangvalidator -V displacement.tese -o displacement.tese.spv
+