make font atlas generator interface more uniform and implement bitmap font atlas rendering and generation

openVulkanoCpp/Shader/sdfText.frag

@@ -0,0 +1,39 @@
+#version 450
+
+layout(location = 1) in vec2 texCoord;
+
+layout(location = 0) out vec4 outColor;
+
+layout(set = 2, binding = 0) uniform sampler2D texSampler;
+
+layout(set = 3, binding = 0) uniform TextConfig
+{
+  vec4 textColor;
+  vec4 borderColor;
+  vec4 backgroundColor;
+  float threshold;
+	float borderSize;
+	float smoothing;
+	bool applyBorder;
+} textConfig;
+
+void main()
+{
+    float distance = texture(texSampler, texCoord).r;
+    float alpha = smoothstep(textConfig.threshold - textConfig.smoothing, textConfig.threshold + textConfig.smoothing, distance);
+    if (textConfig.applyBorder)
+    {
+        float border = smoothstep(textConfig.threshold + textConfig.borderSize - textConfig.smoothing, 
+                                  textConfig.threshold + textConfig.borderSize + textConfig.smoothing, distance);
+        outColor = mix(textConfig.borderColor, textConfig.textColor, border) * alpha;
+    }
+    else
+    {
+        outColor = vec4(textConfig.textColor) * alpha; 
+    }
+
+    if (textConfig.backgroundColor.a != 0)
+    {
+        outColor = mix(textConfig.backgroundColor, outColor, alpha);
+    }
+}