opengl: VertexArray

src/main.zig

@@ -50,11 +50,11 @@ pub fn main() !void {
         0.5, -0.5, 0.0, // right
         0.0, 0.5, 0.0, // top
     };
-    var vao: c_uint = undefined;
+    const vao = try gl.VertexArray.create();
+    defer vao.destroy();
     var vbo: c_uint = undefined;
-    c.glGenVertexArrays(1, &vao);
     c.glGenBuffers(1, &vbo);
-    c.glBindVertexArray(vao);
+    try vao.bind();
 
     c.glBindBuffer(c.GL_ARRAY_BUFFER, vbo);
     c.glBufferData(
@@ -83,8 +83,8 @@ pub fn main() !void {
         c.glClearColor(0.2, 0.3, 0.3, 1.0);
         c.glClear(c.GL_COLOR_BUFFER_BIT);
 
-        c.glUseProgram(program.id);
+        try program.use();
-        c.glBindVertexArray(vao);
+        try vao.bind();
         c.glDrawArrays(c.GL_TRIANGLES, 0, 3);
 
         // const pos = try window.getCursorPos();

src/opengl.zig

@@ -1,3 +1,14 @@
+//! OpenGL bindings.
+//!
+//! These are pupose-built for usage within this program. While they closely
+//! align with the OpenGL C APIs, they aren't meant to be general purpose.
+//! Certain use cases will CERTAINLY be sub-optimal by using these helpers
+//! and should use the C API directly.
+//!
+//! For performance-intensive or unsupported aspects of OpenGL, the C
+//! API is exposed via the `c` constant.
+
 pub const c = @import("opengl/c.zig");
 pub const Program = @import("opengl/Program.zig");
 pub const Shader = @import("opengl/Shader.zig");
+pub const VertexArray = @import("opengl/VertexArray.zig");

src/opengl/Program.zig

@@ -10,7 +10,7 @@ const errors = @import("errors.zig");
 
 id: c.GLuint,
 
-pub fn create() !Program {
+pub inline fn create() !Program {
     const id = c.glCreateProgram();
     if (id == 0) try errors.mustError();
 
@@ -18,12 +18,12 @@ pub fn create() !Program {
     return Program{ .id = id };
 }
 
-pub fn attachShader(p: Program, s: Shader) !void {
+pub inline fn attachShader(p: Program, s: Shader) !void {
     c.glAttachShader(p.id, s.id);
     try errors.getError();
 }
 
-pub fn link(p: Program) !void {
+pub inline fn link(p: Program) !void {
     c.glLinkProgram(p.id);
 
     // Check if linking succeeded
@@ -41,19 +41,23 @@ pub fn link(p: Program) !void {
     return error.CompileFailed;
 }
 
+pub inline fn use(p: Program) !void {
+    c.glUseProgram(p.id);
+}
+
 /// getInfoLog returns the info log for this program. This attempts to
 /// keep the log fully stack allocated and is therefore limited to a max
 /// amount of elements.
 //
 // NOTE(mitchellh): we can add a dynamic version that uses an allocator
 // if we ever need it.
-pub fn getInfoLog(s: Program) [512]u8 {
+pub inline fn getInfoLog(s: Program) [512]u8 {
     var msg: [512]u8 = undefined;
     c.glGetProgramInfoLog(s.id, msg.len, null, &msg);
     return msg;
 }
 
-pub fn destroy(p: Program) void {
+pub inline fn destroy(p: Program) void {
     assert(p.id != 0);
     c.glDeleteProgram(p.id);
     log.debug("program destroyed id={}", .{p.id});

src/opengl/Shader.zig

@@ -9,7 +9,7 @@ const errors = @import("errors.zig");
 
 id: c.GLuint,
 
-pub fn create(typ: c.GLenum) errors.Error!Shader {
+pub inline fn create(typ: c.GLenum) errors.Error!Shader {
     const id = c.glCreateShader(typ);
     if (id == 0) {
         try errors.mustError();
@@ -21,7 +21,7 @@ pub fn create(typ: c.GLenum) errors.Error!Shader {
 }
 
 /// Set the source and compile a shader.
-pub fn setSourceAndCompile(s: Shader, source: [:0]const u8) !void {
+pub inline fn setSourceAndCompile(s: Shader, source: [:0]const u8) !void {
     c.glShaderSource(s.id, 1, &@ptrCast([*c]const u8, source), null);
     c.glCompileShader(s.id);
 
@@ -42,13 +42,13 @@ pub fn setSourceAndCompile(s: Shader, source: [:0]const u8) !void {
 //
 // NOTE(mitchellh): we can add a dynamic version that uses an allocator
 // if we ever need it.
-pub fn getInfoLog(s: Shader) [512]u8 {
+pub inline fn getInfoLog(s: Shader) [512]u8 {
     var msg: [512]u8 = undefined;
     c.glGetShaderInfoLog(s.id, msg.len, null, &msg);
     return msg;
 }
 
-pub fn destroy(s: Shader) void {
+pub inline fn destroy(s: Shader) void {
     assert(s.id != 0);
     c.glDeleteShader(s.id);
     log.debug("shader destroyed id={}", .{s.id});

src/opengl/VertexArray.zig

@@ -0,0 +1,21 @@
+const VertexArray = @This();
+
+const c = @import("c.zig");
+
+id: c.GLuint,
+
+/// Create a single vertex array object.
+pub inline fn create() !VertexArray {
+    var vao: c.GLuint = undefined;
+    c.glGenVertexArrays(1, &vao);
+    return VertexArray{ .id = vao };
+}
+
+/// glBindVertexArray
+pub inline fn bind(v: VertexArray) !void {
+    c.glBindVertexArray(v.id);
+}
+
+pub inline fn destroy(v: VertexArray) void {
+    c.glDeleteVertexArrays(1, &v.id);
+}