Move rendering out of main

src/Renderer.zig

@@ -0,0 +1,97 @@
+const sdl = @import("sdl2");
+const gl = @import("zgl");
+
+const Self = @This();
+
+window: sdl.Window,
+context: sdl.gl.Context,
+color_loc: u32,
+buffer: gl.Buffer,
+
+pub fn init() !Self {
+    try sdl.init(.{ .video = true, .audio = true, .events = true });
+
+    // Set OpenGL version
+    try sdl.gl.setAttribute(.{ .context_major_version = 3 });
+    try sdl.gl.setAttribute(.{ .context_minor_version = 3 });
+
+    const window = try sdl.createWindow(
+        "USG",
+        .{ .centered = {} },
+        .{ .centered = {} },
+        1280,
+        720,
+        .{ .opengl = true, .shown = true }
+    );
+
+    const ctx = try sdl.gl.createContext(window);
+
+    var color_loc: u32 = undefined;
+    const program = gl.Program.create();
+    {
+        const vs = gl.Shader.create(.vertex);
+        defer vs.delete();
+        vs.source(1, &.{@embedFile("shaders/vector.vs")});
+        vs.compile();
+        const fs = gl.Shader.create(.fragment);
+        defer fs.delete();
+        fs.source(1, &.{@embedFile("shaders/fragment.fs")});
+        fs.compile();
+        program.attach(vs);
+        defer program.detach(vs);
+        program.attach(fs);
+        defer program.detach(fs);
+        program.link();
+        color_loc = program.uniformLocation("color").?;
+    }
+    program.use();
+
+    var vertex_array = gl.VertexArray.gen();
+    vertex_array.bind();
+
+    const vertex_buffer = [_]f32{
+        -1.0, -1.0, 0.0,
+        -1.0, 1.0, 0.0,
+        0.0, 1.0, 0.0,
+        1.0, 1.0, 0.0,
+        0.0, -1.0, 0.0,
+        1.0, -1.0, 0.0,
+    };
+
+    const buf = gl.Buffer.gen();
+    buf.bind(.array_buffer);
+    buf.data(f32, &vertex_buffer, .static_draw);
+
+    gl.clearColor(0.91, 0.97, 1.00, 1.00);
+
+    return Self{
+        .window = window,
+        .context = ctx,
+        .color_loc = color_loc,
+        .buffer = buf,
+    };
+}
+
+pub fn render(self: Self) void {
+    gl.clear(.{ .color = true });
+
+    gl.enableVertexAttribArray(0);
+    self.buffer.bind(.array_buffer);
+    gl.vertexAttribPointer(0, 3, .float, false, 0, 0);
+
+    gl.uniform4f(self.color_loc, 0.45, 0.21, 0.70, 1);
+    gl.drawArrays(.triangles, 0, 3);
+
+    gl.uniform4f(self.color_loc, 0.2, 0.5, 1.0, 1);
+    gl.drawArrays(.triangles, 3, 3);
+
+    gl.disableVertexAttribArray(0);
+
+    sdl.gl.swapWindow(self.window);
+}
+
+pub fn deinit(self: Self) void {
+    sdl.quit();
+    self.window.destroy();
+    sdl.gl.deleteContext(self.context);
+}

src/main.zig

@@ -1,71 +1,15 @@
 const std = @import("std");
 const sdl = @import("sdl2");
-const gl = @import("zgl");
 
+const Renderer = @import("Renderer.zig");
 //const Game = @import("Game.zig");
 //const MainMenu = @import("MainMenu.zig");
 
 //const State = @import("flow.zig").State;
 
 pub fn main() !void {
-    try sdl.init(.{ .video = true, .audio = true, .events = true });
+    var renderer = try Renderer.init();
-    defer sdl.quit();
+    defer renderer.deinit();
-
-    // Set OpenGL version
-    try sdl.gl.setAttribute(.{ .context_major_version = 3 });
-    try sdl.gl.setAttribute(.{ .context_minor_version = 3 });
-
-    const window = try sdl.createWindow(
-        "USG",
-        .{ .centered = {} },
-        .{ .centered = {} },
-        1280,
-        720,
-        .{ .opengl = true, .shown = true }
-    );
-    defer window.destroy();
-
-    const ctx = try sdl.gl.createContext(window);
-    defer sdl.gl.deleteContext(ctx);
-
-    var color_loc: u32 = undefined;
-    const program = gl.Program.create();
-    {
-        const vs = gl.Shader.create(.vertex);
-        defer vs.delete();
-        vs.source(1, &.{@embedFile("shaders/vector.vs")});
-        vs.compile();
-        const fs = gl.Shader.create(.fragment);
-        defer fs.delete();
-        fs.source(1, &.{@embedFile("shaders/fragment.fs")});
-        fs.compile();
-        program.attach(vs);
-        defer program.detach(vs);
-        program.attach(fs);
-        defer program.detach(fs);
-        program.link();
-        color_loc = program.uniformLocation("color").?;
-    }
-    program.use();
-
-    var vertex_array = gl.VertexArray.gen();
-    vertex_array.bind();
-
-    const vertex_buffer = [_]f32{
-        -1.0, -1.0, 0.0,
-        -1.0, 1.0, 0.0,
-        0.0, 1.0, 0.0,
-        1.0, 1.0, 0.0,
-        0.0, -1.0, 0.0,
-        1.0, -1.0, 0.0,
-    };
-
-    const buf = gl.Buffer.gen();
-    buf.bind(.array_buffer);
-    buf.data(f32, &vertex_buffer, .static_draw);
-
-    //var renderer = SDL.SDL_CreateRenderer(window, -1, SDL.SDL_RENDERER_PRESENTVSYNC | SDL.SDL_RENDERER_ACCELERATED) orelse return;
-    //defer _ = SDL.SDL_DestroyRenderer(renderer);
 
     //var main_menu = MainMenu.init();
     //var game = Game.init(renderer);
@@ -74,8 +18,6 @@ pub fn main() !void {
 
     //_ = SDL.IMG_Init(SDL.IMG_INIT_JPG);
 
-    gl.clearColor(0.91, 0.97, 1.00, 1.00);
-
     mainLoop: while (true) {
         while (sdl.pollEvent()) |ev| {
             switch (ev) {
@@ -84,25 +26,12 @@ pub fn main() !void {
             }
         }
 
-        gl.clear(.{ .color = true });
+        renderer.render();
-
-        gl.enableVertexAttribArray(0);
-        buf.bind(.array_buffer);
-        gl.vertexAttribPointer(0, 3, .float, false, 0, 0);
-
-        gl.uniform4f(color_loc, 0.45, 0.21, 0.70, 1);
-        gl.drawArrays(.triangles, 0, 3);
-
-        gl.uniform4f(color_loc, 0.2, 0.5, 1.0, 1);
-        gl.drawArrays(.triangles, 3, 3);
-
-        gl.disableVertexAttribArray(0);
 
         //current_state = switch (current_state) {
             //.main_menu => main_menu.tick(),
             //.game => game.tick(),
         //};
 
-        sdl.gl.swapWindow(window);
     }
 }