renderer/opengl: move opengl API to pkg/opengl

pkg/opengl/VertexArray.zig

@@ -0,0 +1,29 @@
+const VertexArray = @This();
+
+const c = @import("c.zig");
+const glad = @import("glad.zig");
+const errors = @import("errors.zig");
+
+id: c.GLuint,
+
+/// Create a single vertex array object.
+pub inline fn create() !VertexArray {
+    var vao: c.GLuint = undefined;
+    glad.context.GenVertexArrays.?(1, &vao);
+    return VertexArray{ .id = vao };
+}
+
+// Unbind any active vertex array.
+pub inline fn unbind() !void {
+    glad.context.BindVertexArray.?(0);
+}
+
+/// glBindVertexArray
+pub inline fn bind(v: VertexArray) !void {
+    glad.context.BindVertexArray.?(v.id);
+    try errors.getError();
+}
+
+pub inline fn destroy(v: VertexArray) void {
+    glad.context.DeleteVertexArrays.?(1, &v.id);
+}