opengl: a lot more enums

src/TextRenderer.zig

@@ -55,22 +55,22 @@ pub fn init(alloc: std.mem.Allocator) !TextRenderer {
 
         // Generate the texture
         const tex = try gl.Texture.create();
-        var binding = try tex.bind(gl.c.GL_TEXTURE_2D);
+        var binding = try tex.bind(.@"2D");
         defer binding.unbind();
         try binding.image2D(
             0,
-            gl.c.GL_RED,
+            .Red,
             @intCast(c_int, face.*.glyph.*.bitmap.width),
             @intCast(c_int, face.*.glyph.*.bitmap.rows),
             0,
-            gl.c.GL_RED,
+            .Red,
-            gl.c.GL_UNSIGNED_BYTE,
+            .UnsignedByte,
             face.*.glyph.*.bitmap.buffer,
         );
-        try binding.parameter(gl.c.GL_TEXTURE_WRAP_S, gl.c.GL_CLAMP_TO_EDGE);
+        try binding.parameter(.WrapS, gl.c.GL_CLAMP_TO_EDGE);
-        try binding.parameter(gl.c.GL_TEXTURE_WRAP_T, gl.c.GL_CLAMP_TO_EDGE);
+        try binding.parameter(.WrapT, gl.c.GL_CLAMP_TO_EDGE);
-        try binding.parameter(gl.c.GL_TEXTURE_MIN_FILTER, gl.c.GL_LINEAR);
+        try binding.parameter(.MinFilter, gl.c.GL_LINEAR);
-        try binding.parameter(gl.c.GL_TEXTURE_MAG_FILTER, gl.c.GL_LINEAR);
+        try binding.parameter(.MagFilter, gl.c.GL_LINEAR);
 
         // Store the character
         chars.appendAssumeCapacity(.{
@@ -91,8 +91,8 @@ pub fn init(alloc: std.mem.Allocator) !TextRenderer {
     const vao = try gl.VertexArray.create();
     const vbo = try gl.Buffer.create();
     try vao.bind();
-    var binding = try vbo.bind(gl.c.GL_ARRAY_BUFFER);
+    var binding = try vbo.bind(.ArrayBuffer);
-    try binding.setDataType([6 * 4]f32, gl.c.GL_DYNAMIC_DRAW);
+    try binding.setDataNull([6 * 4]f32, .DynamicDraw);
     try binding.enableVertexAttribArray(0);
     try binding.vertexAttribPointer(0, 4, gl.c.GL_FLOAT, false, 4 * @sizeOf(f32), null);
     binding.unbind();
@@ -179,9 +179,9 @@ pub fn render(
             .{ xpos + w, ypos + h, 1.0, 0.0 },
         };
 
-        var texbind = try char.tex.bind(gl.c.GL_TEXTURE_2D);
+        var texbind = try char.tex.bind(.@"2D");
         defer texbind.unbind();
-        var bind = try self.vbo.bind(gl.c.GL_ARRAY_BUFFER);
+        var bind = try self.vbo.bind(.ArrayBuffer);
         try bind.setSubData(0, vert);
         bind.unbind();
 

src/opengl/Buffer.zig

@@ -6,21 +6,41 @@ const errors = @import("errors.zig");
 
 id: c.GLuint,
 
+/// Enum for possible binding targets.
+pub const Target = enum(c_uint) {
+    ArrayBuffer = c.GL_ARRAY_BUFFER,
+    _,
+};
+
+/// Enum for possible buffer usages.
+pub const Usage = enum(c_uint) {
+    StreamDraw = c.GL_STREAM_DRAW,
+    StreamRead = c.GL_STREAM_READ,
+    StreamCopy = c.GL_STREAM_COPY,
+    StaticDraw = c.GL_STATIC_DRAW,
+    StaticRead = c.GL_STATIC_READ,
+    StaticCopy = c.GL_STATIC_COPY,
+    DynamicDraw = c.GL_DYNAMIC_DRAW,
+    DynamicRead = c.GL_DYNAMIC_READ,
+    DynamicCopy = c.GL_DYNAMIC_COPY,
+    _,
+};
+
 /// Binding is a bound buffer. By using this for functions that operate
 /// on bound buffers, you can easily defer unbinding and in safety-enabled
 /// modes verify that unbound buffers are never accessed.
 pub const Binding = struct {
-    target: c.GLenum,
+    target: Target,
 
     /// Sets the data of this bound buffer. The data can be any array-like
     /// type. The size of the data is automatically determined based on the type.
     pub inline fn setData(
         b: Binding,
         data: anytype,
-        usage: c.GLenum,
+        usage: Usage,
     ) !void {
         const info = dataInfo(data);
-        c.glBufferData(b.target, info.size, info.ptr, usage);
+        c.glBufferData(@enumToInt(b.target), info.size, info.ptr, @enumToInt(usage));
         try errors.getError();
     }
 
@@ -32,19 +52,19 @@ pub const Binding = struct {
         data: anytype,
     ) !void {
         const info = dataInfo(data);
-        c.glBufferSubData(b.target, @intCast(c_long, offset), info.size, info.ptr);
+        c.glBufferSubData(@enumToInt(b.target), @intCast(c_long, offset), info.size, info.ptr);
         try errors.getError();
     }
 
     /// Sets the buffer data with a null buffer that is expected to be
     /// filled in the future using subData. This requires the type just so
     /// we can setup the data size.
-    pub inline fn setDataType(
+    pub inline fn setDataNull(
         b: Binding,
         comptime T: type,
-        usage: c.GLenum,
+        usage: Usage,
     ) !void {
-        c.glBufferData(b.target, @sizeOf(T), null, usage);
+        c.glBufferData(@enumToInt(b.target), @sizeOf(T), null, @enumToInt(usage));
         try errors.getError();
     }
 
@@ -97,7 +117,7 @@ pub const Binding = struct {
     }
 
     pub inline fn unbind(b: *Binding) void {
-        c.glBindBuffer(b.target, 0);
+        c.glBindBuffer(@enumToInt(b.target), 0);
         b.* = undefined;
     }
 };
@@ -110,8 +130,8 @@ pub inline fn create() !Buffer {
 }
 
 /// glBindBuffer
-pub inline fn bind(v: Buffer, target: c.GLenum) !Binding {
+pub inline fn bind(v: Buffer, target: Target) !Binding {
-    c.glBindBuffer(target, v.id);
+    c.glBindBuffer(@enumToInt(target), v.id);
     return Binding{ .target = target };
 }
 

src/opengl/Texture.zig

@@ -10,21 +10,83 @@ pub inline fn active(target: c.GLenum) !void {
     c.glActiveTexture(target);
 }
 
+/// Enun for possible texture binding targets.
+pub const Target = enum(c_uint) {
+    @"1D" = c.GL_TEXTURE_1D,
+    @"2D" = c.GL_TEXTURE_2D,
+    @"3D" = c.GL_TEXTURE_3D,
+    @"1DArray" = c.GL_TEXTURE_1D_ARRAY,
+    @"2DArray" = c.GL_TEXTURE_2D_ARRAY,
+    Rectangle = c.GL_TEXTURE_RECTANGLE,
+    CubeMap = c.GL_TEXTURE_CUBE_MAP,
+    Buffer = c.GL_TEXTURE_BUFFER,
+    @"2DMultisample" = c.GL_TEXTURE_2D_MULTISAMPLE,
+    @"2DMultisampleArray" = c.GL_TEXTURE_2D_MULTISAMPLE_ARRAY,
+};
+
+/// Enum for possible texture parameters.
+pub const Parameter = enum(c_uint) {
+    BaseLevel = c.GL_TEXTURE_BASE_LEVEL,
+    CompareFunc = c.GL_TEXTURE_COMPARE_FUNC,
+    CompareMode = c.GL_TEXTURE_COMPARE_MODE,
+    LodBias = c.GL_TEXTURE_LOD_BIAS,
+    MinFilter = c.GL_TEXTURE_MIN_FILTER,
+    MagFilter = c.GL_TEXTURE_MAG_FILTER,
+    MinLod = c.GL_TEXTURE_MIN_LOD,
+    MaxLod = c.GL_TEXTURE_MAX_LOD,
+    MaxLevel = c.GL_TEXTURE_MAX_LEVEL,
+    SwizzleR = c.GL_TEXTURE_SWIZZLE_R,
+    SwizzleG = c.GL_TEXTURE_SWIZZLE_G,
+    SwizzleB = c.GL_TEXTURE_SWIZZLE_B,
+    SwizzleA = c.GL_TEXTURE_SWIZZLE_A,
+    WrapS = c.GL_TEXTURE_WRAP_S,
+    WrapT = c.GL_TEXTURE_WRAP_T,
+    WrapR = c.GL_TEXTURE_WRAP_R,
+};
+
+/// Internal format enum for texture images.
+pub const InternalFormat = enum(c_int) {
+    Red = c.GL_RED,
+
+    // There are so many more that I haven't filled in.
+    _,
+};
+
+/// Format for texture images
+pub const Format = enum(c_uint) {
+    Red = c.GL_RED,
+
+    // There are so many more that I haven't filled in.
+    _,
+};
+
+/// Data type for texture images.
+pub const DataType = enum(c_uint) {
+    UnsignedByte = c.GL_UNSIGNED_BYTE,
+
+    // There are so many more that I haven't filled in.
+    _,
+};
+
 pub const Binding = struct {
-    target: c.GLenum,
+    target: Target,
 
     pub inline fn unbind(b: *Binding) void {
-        c.glBindTexture(b.target, 0);
+        c.glBindTexture(@enumToInt(b.target), 0);
         b.* = undefined;
     }
 
     pub fn generateMipmap(b: Binding) void {
-        c.glGenerateMipmap(b.target);
+        c.glGenerateMipmap(@enumToInt(b.target));
     }
 
-    pub fn parameter(b: Binding, name: c.GLenum, value: anytype) !void {
+    pub fn parameter(b: Binding, name: Parameter, value: anytype) !void {
         switch (@TypeOf(value)) {
-            c.GLint => c.glTexParameteri(b.target, name, value),
+            c.GLint => c.glTexParameteri(
+                @enumToInt(b.target),
+                @enumToInt(name),
+                value,
+            ),
             else => unreachable,
         }
     }
@@ -32,23 +94,23 @@ pub const Binding = struct {
     pub fn image2D(
         b: Binding,
         level: c.GLint,
-        internal_format: c.GLint,
+        internal_format: InternalFormat,
         width: c.GLsizei,
         height: c.GLsizei,
         border: c.GLint,
-        format: c.GLenum,
+        format: Format,
-        typ: c.GLenum,
+        typ: DataType,
         data: ?*const anyopaque,
     ) !void {
         c.glTexImage2D(
-            b.target,
+            @enumToInt(b.target),
             level,
-            internal_format,
+            @enumToInt(internal_format),
             width,
             height,
             border,
-            format,
+            @enumToInt(format),
-            typ,
+            @enumToInt(typ),
             data,
         );
     }
@@ -62,8 +124,8 @@ pub inline fn create() !Texture {
 }
 
 /// glBindTexture
-pub inline fn bind(v: Texture, target: c.GLenum) !Binding {
+pub inline fn bind(v: Texture, target: Target) !Binding {
-    c.glBindTexture(target, v.id);
+    c.glBindTexture(@enumToInt(target), v.id);
     return Binding{ .target = target };
 }