GLSL Porting from v110 to v150? - c++

Question

I'm attempting to port shaders from #version 110 to 150. I'm aware that when moving from 110 to 150 the global gl_ properties are deprecated and therefore all those properties will have to be specified manually in the shader. Then the specified properties have to be set through C++ via calls to OpenGL through glGetAttribLocation.
I'm a little unsure how to handle things such as gl_MultiTexCoord0 and gl_TexCoord.
Here of just one of the shaders I'm attempting to port from #version 110 to 150:
// blinn_phong.glsl
[vert]
#version 110
varying vec3 normal;
void main()
{
normal = normalize(gl_NormalMatrix * gl_Normal);
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
gl_TexCoord[0] = gl_MultiTexCoord0;
}
[frag]
#version 110
uniform sampler2D colorMap;
uniform float materialAlpha;
varying vec3 normal;
void main()
{
vec3 n = normalize(normal);
float nDotL = max(0.0, dot(n, gl_LightSource[0].position.xyz));
float nDotH = max(0.0, dot(normal, vec3(gl_LightSource[0].halfVector)));
float power = (nDotL == 0.0) ? 0.0 : pow(nDotH, gl_FrontMaterial.shininess);
vec4 ambient = gl_FrontLightProduct[0].ambient;
vec4 diffuse = gl_FrontLightProduct[0].diffuse * nDotL;
vec4 specular = gl_FrontLightProduct[0].specular * power;
vec4 color = gl_FrontLightModelProduct.sceneColor + ambient + diffuse + specular;
gl_FragColor = color * texture2D(colorMap, gl_TexCoord[0].st);
gl_FragColor.a = materialAlpha;
}
Can anyone provide some good resources to help with porting between these versions?

Answer 1

You will have to setup your own uniforms, attributes, varyings and fragment shader outputs. The code will become similar to:
[vert]
#version 150 core
uniform mat3 in_NormalMatrix;
uniform mat4 in_ModelViewProjectionMatrix;
in vec3 in_Normal;
in vec4 in_Vertex;
in vec2 in_MultiTexCoord;
out vec3 normal;
out vec2 texcoord;
void main()
{
normal = normalize(in_NormalMatrix * in_Normal);
gl_Position = in_ModelViewProjectionMatrix * in_Vertex;
texcoord = in_MultiTexCoord;
}
[frag]
#version 150
uniform sampler2D colorMap;
uniform float materialAlpha;
struct sLightSource
{
vec3 position;
vec3 halfVector;
...
}
uniform sLightSource u_LightSource;
in vec3 normal;
in vec2 texcoord;
out vec4 out_FragColor;
void main()
{
vec3 n = normalize(normal);
float nDotL = max(0.0, dot(n, u_LightSource.position.xyz));
float nDotH = max(0.0, dot(normal, vec3(u_LightSource.halfVector)));
...
out_FragColor = color * texture(colorMap, texcoord);
out_FragColor.a = materialAlpha;
}
P.S. This book has an entire chapter dedicated to this kind of transformations between different GLSL shader versions.