Implement constant wrap mode in shader source to ensure portability across languages.

Author: ld-kerley

libraries/stdlib/genglsl/mx_image_color3.glsl

@@ -3,5 +3,13 @@
 void mx_image_color3($texSamplerSignature, int layer, vec3 defaultval, vec2 texcoord, int uaddressmode, int vaddressmode, int filtertype, int framerange, int frameoffset, int frameendaction, vec2 uv_scale, vec2 uv_offset, out vec3 result)
 {
     vec2 uv = mx_transform_uv(texcoord, uv_scale, uv_offset);
+
+    // "constant" wrap mode directly implemented in shader source because MSL and GLSL implementations don't align
+    if ((uaddressmode == 0 && (uv[0] < 0 || uv[0] > 1)) || (vaddressmode == 0 && (uv[1] < 0 || uv[1] > 1)))
+    {
+        result = defaultval;
+        return;
+    }
+
     result = texture($texSamplerSampler2D, uv).rgb;
 }

libraries/stdlib/genglsl/mx_image_color4.glsl

@@ -3,5 +3,13 @@
 void mx_image_color4($texSamplerSignature, int layer, vec4 defaultval, vec2 texcoord, int uaddressmode, int vaddressmode, int filtertype, int framerange, int frameoffset, int frameendaction, vec2 uv_scale, vec2 uv_offset, out vec4 result)
 {
     vec2 uv = mx_transform_uv(texcoord, uv_scale, uv_offset);
+
+    // "constant" wrap mode directly implemented in shader source because MSL and GLSL implementations don't align
+    if ((uaddressmode == 0 && (uv[0] < 0 || uv[0] > 1)) || (vaddressmode == 0 && (uv[1] < 0 || uv[1] > 1)))
+    {
+        result = defaultval;
+        return;
+    }
+
     result = texture($texSamplerSampler2D, uv);
 }

libraries/stdlib/genglsl/mx_image_float.glsl

@@ -3,5 +3,13 @@
 void mx_image_float($texSamplerSignature, int layer, float defaultval, vec2 texcoord, int uaddressmode, int vaddressmode, int filtertype, int framerange, int frameoffset, int frameendaction, vec2 uv_scale, vec2 uv_offset, out float result)
 {
     vec2 uv = mx_transform_uv(texcoord, uv_scale, uv_offset);
+
+    // "constant" wrap mode directly implemented in shader source because MSL and GLSL implementations don't align
+    if ((uaddressmode == 0 && (uv[0] < 0 || uv[0] > 1)) || (vaddressmode == 0 && (uv[1] < 0 || uv[1] > 1)))
+    {
+        result = defaultval;
+        return;
+    }
+
     result = texture($texSamplerSampler2D, uv).r;
 }

libraries/stdlib/genglsl/mx_image_vector2.glsl

@@ -3,5 +3,13 @@
 void mx_image_vector2($texSamplerSignature, int layer, vec2 defaultval, vec2 texcoord, int uaddressmode, int vaddressmode, int filtertype, int framerange, int frameoffset, int frameendaction, vec2 uv_scale, vec2 uv_offset, out vec2 result)
 {
     vec2 uv = mx_transform_uv(texcoord, uv_scale, uv_offset);
+
+    // "constant" wrap mode directly implemented in shader source because MSL and GLSL implementations don't align
+    if ((uaddressmode == 0 && (uv[0] < 0 || uv[0] > 1)) || (vaddressmode == 0 && (uv[1] < 0 || uv[1] > 1)))
+    {
+        result = defaultval;
+        return;
+    }
+
     result = texture($texSamplerSampler2D, uv).rg;
 }

libraries/stdlib/genglsl/mx_image_vector3.glsl

@@ -3,5 +3,13 @@
 void mx_image_vector3($texSamplerSignature, int layer, vec3 defaultval, vec2 texcoord, int uaddressmode, int vaddressmode, int filtertype, int framerange, int frameoffset, int frameendaction, vec2 uv_scale, vec2 uv_offset, out vec3 result)
 {
     vec2 uv = mx_transform_uv(texcoord, uv_scale, uv_offset);
+
+    // "constant" wrap mode directly implemented in shader source because MSL and GLSL implementations don't align
+    if ((uaddressmode == 0 && (uv[0] < 0 || uv[0] > 1)) || (vaddressmode == 0 && (uv[1] < 0 || uv[1] > 1)))
+    {
+        result = defaultval;
+        return;
+    }
+
     result = texture($texSamplerSampler2D, uv).rgb;
 }

libraries/stdlib/genglsl/mx_image_vector4.glsl

@@ -3,5 +3,13 @@
 void mx_image_vector4($texSamplerSignature, int layer, vec4 defaultval, vec2 texcoord, int uaddressmode, int vaddressmode, int filtertype, int framerange, int frameoffset, int frameendaction, vec2 uv_scale, vec2 uv_offset, out vec4 result)
 {
     vec2 uv = mx_transform_uv(texcoord, uv_scale, uv_offset);
+
+    // "constant" wrap mode directly implemented in shader source because MSL and GLSL implementations don't align
+    if ((uaddressmode == 0 && (uv[0] < 0 || uv[0] > 1)) || (vaddressmode == 0 && (uv[1] < 0 || uv[1] > 1)))
+    {
+        result = defaultval;
+        return;
+    }
+
     result = texture($texSamplerSampler2D, uv);
 }