Merge branch 'render-with-outline' of https://github.com/dov/vsgExamples into dov-render-with-outline

Author: robertosfield

data/shaders/shader_Outline.frag

@@ -0,0 +1,38 @@
+#version 450
+#extension GL_ARB_separate_shader_objects : enable
+
+layout(binding = 0) uniform sampler2D texSampler;
+
+layout(location = 0) in vec3 fragColor;
+layout(location = 1) in vec2 fragTexCoord;
+
+layout(location = 0) out vec4 outColor;
+
+void main() {
+    vec4 shadowColor = {1.0,0.5,0.0,0.5 };  // Color of the shadow/outline
+
+    vec2 texSize = textureSize(texSampler, 0);
+    vec2 texOffset = vec2(1.0) / texSize; // Size of a single texel
+
+    float shadowAlpha = 0.0;
+
+    shadowAlpha = 0.0;
+    int n=3; // Size of surrounding for outline sampling
+    for (int x=-n; x<=n; ++x) {
+      for (int y=-n; y<=n; ++y) {
+          shadowAlpha += texture(texSampler,
+                                 +fragTexCoord
+                                 +vec2(x,y)*texOffset).a;
+      }
+    }
+
+    // Get the original texture color
+    vec4 original = texture(texSampler, fragTexCoord);
+
+    // First combine the shadow with the background color
+    outColor = mix(vec4(0.1,0.1,0.3,1.0), shadowColor, min(shadowAlpha,1.0));
+
+    // Now combine with the original model
+    outColor = mix(outColor, original, original.a);
+}
+

examples/app/CMakeLists.txt

@@ -19,6 +19,7 @@ add_subdirectory(vsgvalidate)
 add_subdirectory(vsgaxes)
 add_subdirectory(vsgcolorspace)
 add_subdirectory(vsgmultiwindowmultiview)
+add_subdirectory(vsgrenderoutline)
 
 if (vsgXchange_FOUND)
     add_subdirectory(vsghelloworld)

examples/app/vsgrenderoutline/CMakeLists.txt

@@ -0,0 +1,14 @@
+set(SOURCES
+    vsgrenderoutline.cpp
+)
+
+add_executable(vsgrenderoutline ${SOURCES})
+
+target_link_libraries(vsgrenderoutline vsg::vsg)
+
+if (vsgXchange_FOUND)
+    target_compile_definitions(vsgrenderoutline PRIVATE vsgXchange_FOUND)
+    target_link_libraries(vsgrenderoutline vsgXchange::vsgXchange)
+endif()
+
+install(TARGETS vsgrenderoutline RUNTIME DESTINATION bin)