Started work on a text overlay rendering example using a separate render pass for drawing on top of the current framebuffer

data/shaders/textoverlay/generate-spirv.bat

@@ -0,0 +1,4 @@
+glslangvalidator -V text.vert -o text.vert.spv
+glslangvalidator -V text.frag -o text.frag.spv
+glslangvalidator -V mesh.vert -o mesh.vert.spv
+glslangvalidator -V mesh.frag -o mesh.frag.spv

data/shaders/textoverlay/mesh.frag

@@ -0,0 +1,29 @@
+#version 450
+
+#extension GL_ARB_separate_shader_objects : enable
+#extension GL_ARB_shading_language_420pack : enable
+
+layout (binding = 1) uniform sampler2D samplerColorMap;
+
+layout (location = 0) in vec3 inNormal;
+layout (location = 1) in vec3 inColor;
+layout (location = 2) in vec2 inUV;
+layout (location = 3) in vec3 inViewVec;
+layout (location = 4) in vec3 inLightVec;
+
+layout (location = 0) out vec4 outFragColor;
+
+void main() 
+{
+	vec4 color = texture(samplerColorMap, inUV) * vec4(inColor, 1.0);
+
+	vec3 N = normalize(inNormal);
+	vec3 L = normalize(inLightVec);
+	vec3 V = normalize(inViewVec);
+	vec3 R = reflect(-L, N);
+	vec3 diffuse = max(dot(N, L), 0.0) * inColor;
+	vec3 specular = pow(max(dot(R, V), 0.0), 16.0) * vec3(0.75);
+	outFragColor = vec4(diffuse * color.rgb + specular, 1.0);	
+	
+	outFragColor.rgb = vec3(diffuse + specular);
+}

data/shaders/textoverlay/mesh.vert

@@ -0,0 +1,36 @@
+#version 450
+
+#extension GL_ARB_separate_shader_objects : enable
+#extension GL_ARB_shading_language_420pack : enable
+
+layout (location = 0) in vec3 inPos;
+layout (location = 1) in vec3 inNormal;
+layout (location = 2) in vec2 inUV;
+layout (location = 3) in vec3 inColor;
+
+layout (binding = 0) uniform UBO 
+{
+	mat4 projection;
+	mat4 model;
+	vec4 lightPos;
+} ubo;
+
+layout (location = 0) out vec3 outNormal;
+layout (location = 1) out vec3 outColor;
+layout (location = 2) out vec2 outUV;
+layout (location = 3) out vec3 outViewVec;
+layout (location = 4) out vec3 outLightVec;
+
+void main() 
+{
+	outNormal = inNormal;
+	outColor = inColor;
+	outUV = inUV;
+	gl_Position = ubo.projection * ubo.model * vec4(inPos.xyz, 1.0);
+	
+    vec4 pos = ubo.model * vec4(inPos, 1.0);
+    outNormal = /*mat3(ubo.model) */ inNormal;
+	vec3 lPos = /*mat3(ubo.model) */ ubo.lightPos.xyz;
+    outLightVec = lPos - pos.xyz;
+    outViewVec = -pos.xyz;		
+}

data/shaders/textoverlay/text.frag

@@ -0,0 +1,13 @@
+#version 450 core
+
+layout (location = 0) in vec2 inUV;
+
+layout (binding = 0) uniform sampler2D samplerFont;
+
+layout (location = 0) out vec4 outFragColor;
+
+void main(void)
+{
+	float color = texture(samplerFont, inUV).r;
+	outFragColor = vec4(vec3(color), 1.0);
+}

data/shaders/textoverlay/text.vert

@@ -0,0 +1,12 @@
+#version 450 core
+
+layout (location = 0) in vec2 inPos;
+layout (location = 1) in vec2 inUV;
+
+layout (location = 0) out vec2 outUV;
+
+void main(void)
+{
+	gl_Position = vec4(inPos, 0.0, 1.0);
+	outUV = inUV;
+}