ended up using the 100 version shaders as off the top of my (#1142)

head can't think of any improvement I could use on the shaders for
version 120
This has been tested on Linux (Desktop) requires testing on a Rpi

Co-authored-by: codifies <[email protected]>

2 files changed, 151 insertions, 0 deletions

diff --git a/examples/shaders/resources/shaders/glsl120/base_lighting.vs b/examples/shaders/resources/shaders/glsl120/base_lighting.vs
new file mode 100644
index 00000000..678c60e9
--- /dev/null
+++ b/examples/shaders/resources/shaders/glsl120/base_lighting.vs
@@ -0,0 +1,59 @@
+#version 120
+
+// Input vertex attributes
+attribute vec3 vertexPosition;
+attribute vec2 vertexTexCoord;
+attribute vec3 vertexNormal;
+attribute vec4 vertexColor;
+
+// Input uniform values
+uniform mat4 mvp;
+uniform mat4 matModel;
+
+// Output vertex attributes (to fragment shader)
+varying vec3 fragPosition;
+varying vec2 fragTexCoord;
+varying vec4 fragColor;
+varying vec3 fragNormal;
+
+// NOTE: Add here your custom variables
+
+// https://github.com/glslify/glsl-inverse
+mat3 inverse(mat3 m)
+{
+  float a00 = m[0][0], a01 = m[0][1], a02 = m[0][2];
+  float a10 = m[1][0], a11 = m[1][1], a12 = m[1][2];
+  float a20 = m[2][0], a21 = m[2][1], a22 = m[2][2];
+
+  float b01 = a22*a11 - a12*a21;
+  float b11 = -a22*a10 + a12*a20;
+  float b21 = a21*a10 - a11*a20;
+
+  float det = a00*b01 + a01*b11 + a02*b21;
+
+  return mat3(b01, (-a22*a01 + a02*a21), (a12*a01 - a02*a11),
+              b11, (a22*a00 - a02*a20), (-a12*a00 + a02*a10),
+              b21, (-a21*a00 + a01*a20), (a11*a00 - a01*a10))/det;
+}
+
+// https://github.com/glslify/glsl-transpose
+mat3 transpose(mat3 m)
+{
+  return mat3(m[0][0], m[1][0], m[2][0],
+              m[0][1], m[1][1], m[2][1],
+              m[0][2], m[1][2], m[2][2]);
+}
+
+void main()
+{
+    // Send vertex attributes to fragment shader
+    fragPosition = vec3(matModel*vec4(vertexPosition, 1.0));
+    fragTexCoord = vertexTexCoord;
+    fragColor = vertexColor;
+    
+    mat3 normalMatrix = transpose(inverse(mat3(matModel)));
+    fragNormal = normalize(normalMatrix*vertexNormal);
+
+    // Calculate final vertex position
+    gl_Position = mvp*vec4(vertexPosition, 1.0);
+}
diff --git a/examples/shaders/resources/shaders/glsl120/fog.fs b/examples/shaders/resources/shaders/glsl120/fog.fs
new file mode 100644
index 00000000..fcd6ef95
--- /dev/null
+++ b/examples/shaders/resources/shaders/glsl120/fog.fs
@@ -0,0 +1,92 @@
+#version 120
+
+// Input vertex attributes (from vertex shader)
+varying vec3 fragPosition;
+varying vec2 fragTexCoord;
+varying vec4 fragColor;
+varying vec3 fragNormal;
+
+// Input uniform values
+uniform sampler2D texture0;
+uniform vec4 colDiffuse;
+
+// NOTE: Add here your custom variables
+
+#define     MAX_LIGHTS              4
+#define     LIGHT_DIRECTIONAL       0
+#define     LIGHT_POINT             1
+
+struct MaterialProperty {
+    vec3 color;
+    int useSampler;
+    sampler2D sampler;
+};
+
+struct Light {
+    int enabled;
+    int type;
+    vec3 position;
+    vec3 target;
+    vec4 color;
+};
+
+// Input lighting values
+uniform Light lights[MAX_LIGHTS];
+uniform vec4 ambient;
+uniform vec3 viewPos;
+uniform float fogDensity;
+
+void main()
+{
+    // Texel color fetching from texture sampler
+    vec4 texelColor = texture2D(texture0, fragTexCoord);
+    vec3 lightDot = vec3(0.0);
+    vec3 normal = normalize(fragNormal);
+    vec3 viewD = normalize(viewPos - fragPosition);
+    vec3 specular = vec3(0.0);
+
+    // NOTE: Implement here your fragment shader code
+
+    for (int i = 0; i < MAX_LIGHTS; i++)
+    {
+        if (lights[i].enabled == 1)
+        {
+            vec3 light = vec3(0.0);
+            
+            if (lights[i].type == LIGHT_DIRECTIONAL) light = -normalize(lights[i].target - lights[i].position);
+            if (lights[i].type == LIGHT_POINT) light = normalize(lights[i].position - fragPosition);
+
+            float NdotL = max(dot(normal, light), 0.0);
+            lightDot += lights[i].color.rgb*NdotL;
+
+            float specCo = 0.0;
+            if (NdotL > 0.0) specCo = pow(max(0.0, dot(viewD, reflect(-(light), normal))), 16.0); // Shine: 16.0
+            specular += specCo;
+        }
+    }
+
+    vec4 finalColor = (texelColor*((colDiffuse + vec4(specular,1))*vec4(lightDot, 1.0)));
+    finalColor += texelColor*(ambient/10.0);
+    
+    // Gamma correction
+    finalColor = pow(finalColor, vec4(1.0/2.2));
+    
+    // Fog calculation
+    float dist = length(viewPos - fragPosition);
+
+    // these could be parameters...
+    const vec4 fogColor = vec4(0.5, 0.5, 0.5, 1.0);
+    //const float fogDensity = 0.16;
+
+    // Exponential fog
+    float fogFactor = 1.0/exp((dist*fogDensity)*(dist*fogDensity));
+
+    // Linear fog (less nice)
+    //const float fogStart = 2.0;
+    //const float fogEnd = 10.0;
+    //float fogFactor = (fogEnd - dist)/(fogEnd - fogStart);
+
+    fogFactor = clamp(fogFactor, 0.0, 1.0);
+
+    gl_FragColor = mix(fogColor, finalColor, fogFactor);
+}