feat: Basic keyword completion

Author: armsnyder

.gitignore

@@ -1,2 +1,3 @@
 /tmp/
 *.test
+gdshader-language-server

.golangci.yaml

@@ -6,6 +6,7 @@ linters:
     - ginkgolinter
     - gocritic
     - godot
+    - goheader
     - gosec
     - govet
     - ineffassign
@@ -42,6 +43,8 @@ linters:
       enable-all: true
       disabled-checks:
         - whyNoLint
+    goheader:
+      template-path: LICENSE
     revive:
       enable-all-rules: true
       rules:

Makefile

@@ -9,14 +9,17 @@ COV_UNIT := $(PWD)/tmp/cover/unit
 COV_E2E := $(PWD)/tmp/cover/e2e
 COV_MERGED := $(PWD)/tmp/cover/merged
 
-reviewable: tidy fmt lint build test
+reviewable: tidy fmt lint-fix lint build test
 
 tidy:
 	go mod tidy
 
 fmt:
 	golangci-lint fmt
 
+lint-fix:
+	golangci-lint run --fix
+
 lint:
 	golangci-lint run
 

README.md

@@ -8,39 +8,35 @@ External editor support for `.gdshader` files.
 > [!WARNING]
 > 🚧 Early Work in Progress
 >
-> This project is in its infancy and currently has no features. Feel free to ⭐
-> the repo to track progress and signal to me that there is interest!
+> This project is in its infancy and currently only supports some basic keyword
+> completion. Feel free to ⭐ the repo to track progress and signal to me that
+> there is interest!
 
 Godot's shader language is powerful, but editing `.gdshader` files outside the
 Godot editor is painful. This project aims to bring proper language tooling
 (autocomplete, hover, references, etc.) to editors like Neovim and VSCode.
 
 ## 📦 Install
 
-Install from source:
+### Neovim
 
-```shell
-go install github.com/armsnyder/gdshader-language-server@latest
-```
+1. Install from source:
 
-## ⚙️  Configure
+   ```shell
+   go install github.com/armsnyder/gdshader-language-server@latest
+   ```
 
-### Neovim
+1. Create a `~/.config/nvim/after/ftplugin/gdshader.lua` file with the following
+   content, adjusting the path to the `gdshader-language-server` binary if
+   necessary:
 
-Add the following to your `init.lua`, adjusting the path to the
-`gdshader-language-server` binary if necessary:
-
-```lua
-vim.api.nvim_create_autocmd("FileType", {
-  pattern = "gdshader",
-  callback = function()
-    vim.lsp.start({
-      name = "gdshader",
-      cmd = { vim.fs.expand('$HOME/go/bin/gdshader-language-server') },
-    })
-  end,
-})
-```
+   ```lua
+   vim.lsp.start({
+     name = "gdshader",
+     cmd = { vim.fs.expand('~/go/bin/gdshader-language-server') },
+     capabilities = vim.lsp.protocol.make_client_capabilities(),
+   })
+   ```
 
 ### VSCode
 
@@ -50,6 +46,10 @@ Coming soon? Contributions welcome!
 
 Planned features:
 
+- [x] Basic keyword completion
+- [ ] Basic shader-type-dependent global built-in completion
+      (`VERTEX`, `NORMAL`, etc.)
+- [ ] More advanced completion (functions, variables, etc.)
 - [ ] Go to definition
 - [ ] Find references
 - [ ] Formatting

e2e_test.go

@@ -1,3 +1,25 @@
+// MIT License
+//
+// Copyright (c) 2025 Adam Snyder
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
 package main_test
 
 import (

internal/app/completion.go

@@ -0,0 +1,181 @@
+// MIT License
+//
+// Copyright (c) 2025 Adam Snyder
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package app
+
+import "github.com/armsnyder/gdshader-language-server/internal/lsp"
+
+var completionItems = func() []lsp.CompletionItem {
+	var items []lsp.CompletionItem
+
+	// https://docs.godotengine.org/en/stable/tutorials/shaders/shader_reference/shading_language.html#data-types
+	dataTypes := map[string]string{
+		"void":               "Void datatype, useful only for functions that return nothing.",
+		"bool":               "Boolean datatype, can only contain `true` or `false`.",
+		"bvec2":              "Two-component vector of booleans.",
+		"bvec3":              "Three-component vector of booleans.",
+		"bvec4":              "Four-component vector of booleans.",
+		"int":                "32 bit signed scalar integer.",
+		"ivec2":              "Two-component vector of signed integers.",
+		"ivec3":              "Three-component vector of signed integers.",
+		"ivec4":              "Four-component vector of signed integers.",
+		"uint":               "Unsigned scalar integer; can't contain negative numbers.",
+		"uvec2":              "Two-component vector of unsigned integers.",
+		"uvec3":              "Three-component vector of unsigned integers.",
+		"uvec4":              "Four-component vector of unsigned integers.",
+		"float":              "32 bit floating-point scalar.",
+		"vec2":               "Two-component vector of floating-point values.",
+		"vec3":               "Three-component vector of floating-point values.",
+		"vec4":               "Four-component vector of floating-point values.",
+		"mat2":               "2x2 matrix, in column major order.",
+		"mat3":               "3x3 matrix, in column major order.",
+		"mat4":               "4x4 matrix, in column major order.",
+		"sampler2D":          "Sampler type for binding 2D textures, which are read as float.",
+		"isampler2D":         "Sampler type for binding 2D textures, which are read as signed integer.",
+		"usampler2D":         "Sampler type for binding 2D textures, which are read as unsigned integer.",
+		"sampler2DArray":     "Sampler type for binding 2D texture arrays, which are read as float.",
+		"isampler2DArray":    "Sampler type for binding 2D texture arrays, which are read as signed integer.",
+		"usampler2DArray":    "Sampler type for binding 2D texture arrays, which are read as unsigned integer.",
+		"sampler3D":          "Sampler type for binding 3D textures, which are read as float.",
+		"isampler3D":         "Sampler type for binding 3D textures, which are read as signed integer.",
+		"usampler3D":         "Sampler type for binding 3D textures, which are read as unsigned integer.",
+		"samplerCube":        "Sampler type for binding Cubemaps, which are read as float.",
+		"samplerCubeArray":   "Sampler type for binding Cubemap arrays, which are read as float. Only supported in Forward+ and Mobile, not Compatibility.",
+		"samplerExternalOES": "External sampler type. Only supported in Compatibility/Android platform.",
+	}
+
+	for label, doc := range dataTypes {
+		items = append(items, lsp.CompletionItem{
+			Label:         label,
+			Kind:          lsp.CompletionClass,
+			Documentation: &lsp.MarkupContent{Kind: lsp.MarkupMarkdown, Value: doc},
+		})
+	}
+
+	// TODO(asnyder): Filter keywords based on context.
+
+	simpleKeywords := []string{"break", "case", "continue", "default", "do", "else", "for", "if", "return", "switch", "while", "const", "struct"}
+
+	for _, keyword := range simpleKeywords {
+		items = append(items, lsp.CompletionItem{
+			Label: keyword,
+			Kind:  lsp.CompletionKeyword,
+		})
+	}
+
+	describedKeywords := map[string]string{
+		// https://docs.godotengine.org/en/stable/tutorials/shaders/shader_reference/shading_language.html#precision
+		"lowp":          "low precision, usually 8 bits per component mapped to 0-1",
+		"mediump":       "medium precision, usually 16 bits or half float",
+		"highp":         "high precision, uses full float or integer range (32 bit default)",
+		"discard":       "Discards the current fragment, preventing it from being drawn. Used in fragment shaders to skip rendering under certain conditions.",
+		"in":            "An agument only for reading",
+		"out":           "An argument only for writing",
+		"inout":         "An argument that is fully passed via reference",
+		"shader_type":   "Declares the type of shader being written, such as `canvas_item`, `spatial`, or `particle`.",
+		"uniform":       "Declares a variable that can be set from outside the shader",
+		"varying":       "Declares a variable that is passed between vertex and fragment shaders",
+		"flat":          "The value is not interpolated",
+		"smooth":        "The value is interpolated in a perspective-correct fashion. This is the default.",
+		"uniform_group": "Group multiple uniforms together in the inspector",
+	}
+
+	for label, doc := range describedKeywords {
+		items = append(items, lsp.CompletionItem{
+			Label: label,
+			Kind:  lsp.CompletionKeyword,
+			Documentation: &lsp.MarkupContent{
+				Kind:  lsp.MarkupMarkdown,
+				Value: doc,
+			},
+		})
+	}
+
+	// Non-function uniform himts.
+	uniformHints := map[string]string{
+		"source_color":                  "Used as color.",
+		"hint_normal":                   "Used as normalmap.",
+		"hint_default_white":            "As value or albedo color, default to opaque white.",
+		"hint_default_black":            "As value or albedo color, default to opaque black.",
+		"hint_default_transparent":      "As value or albedo color, default to transparent black.",
+		"hint_anisotropy":               "As flowmap, default to right.",
+		"repeat_enable":                 "Enabled texture repeating.",
+		"repeat_disable":                "Disabled texture repeating.",
+		"hint_screen_texture":           "Texture is the screen texture.",
+		"hint_depth_texture":            "Texture is the depth texture.",
+		"hint_normal_roughness_texture": "Texture is the normal roughness texture (only supported in Forward+).",
+	}
+
+	roughnessHints := []string{"r", "g", "b", "a", "normal", "gray"}
+	for _, channel := range roughnessHints {
+		uniformHints["hint_roughness_"+channel] = "Used for roughness limiter on import (attempts reducing specular aliasing). `_normal` is a normal map that guides the roughness limiter, with roughness increasing in areas that have high-frequency detail."
+	}
+
+	filterHints := []string{"nearest", "linear", "nearest_mipmap_nearest", "linear_mipmap_nearest", "nearest_mipmap_linear", "linear_mipmap_linear"}
+	for _, filter := range filterHints {
+		uniformHints["hint_filter_"+filter] = "Enabled specified texture filtering."
+	}
+
+	for label, doc := range uniformHints {
+		items = append(items, lsp.CompletionItem{
+			Label:         label,
+			Kind:          lsp.CompletionKeyword,
+			Documentation: &lsp.MarkupContent{Kind: lsp.MarkupMarkdown, Value: doc},
+		})
+	}
+
+	// Function uniform hints.
+	functionUniformHints := map[string]string{
+		"hint_enum":  "Displays int input as a dropdown widget in the editor.",
+		"hint_range": "Displays float input as a slider in the editor.",
+	}
+
+	for label, doc := range functionUniformHints {
+		items = append(items, lsp.CompletionItem{
+			Label:         label,
+			Kind:          lsp.CompletionFunction,
+			Documentation: &lsp.MarkupContent{Kind: lsp.MarkupMarkdown, Value: doc},
+		})
+	}
+
+	// Shader types
+	shaderTypes := map[string]string{
+		"canvas_item": "Canvas item shader, used for 2D rendering.",
+		"spatial":     "Spatial shader, used for 3D rendering.",
+		"particles":   "Particle shader, used for particle systems.",
+		"sky":         "Sky shader, used for rendering skyboxes or skydomes.",
+		"fog":         "Fog shader, used for rendering fog effects.",
+	}
+	for label, doc := range shaderTypes {
+		items = append(items, lsp.CompletionItem{
+			Label:         label,
+			Kind:          lsp.CompletionKeyword,
+			Documentation: &lsp.MarkupContent{Kind: lsp.MarkupMarkdown, Value: doc},
+		})
+	}
+
+	// Built-in variables
+	// https://docs.godotengine.org/en/stable/tutorials/shaders/shader_reference/shading_language.html#built-in-variables
+	// TODO(asnyder): Set variables based on shader type.
+
+	return items
+}()