From ccfeb1fe1b4bf46b1b022dc6a5b74f2455b68368 Mon Sep 17 00:00:00 2001
From: Dendy <dendy@fai.st>
Date: Thu, 21 Jul 2022 17:55:22 +0200
Subject: [PATCH] WIP: open an image and clear with OpenGL

---
 .gitmodules  |  3 ++
 build.zig    |  6 +++-
 lib/zgl      |  1 +
 src/main.zig | 82 ++++++++++++++++++++++++++++------------------------
 4 files changed, 54 insertions(+), 38 deletions(-)
 create mode 160000 lib/zgl

diff --git a/.gitmodules b/.gitmodules
index 92af0ff..ec33071 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "lib/SDL.zig"]
 	path = lib/SDL.zig
 	url = ../SDL.zig
+[submodule "lib/zgl"]
+	path = lib/zgl
+	url = https://github.com/ziglibs/zgl
diff --git a/build.zig b/build.zig
index 5bfd975..d774945 100644
--- a/build.zig
+++ b/build.zig
@@ -17,7 +17,11 @@ pub fn build(b: *std.build.Builder) void {
     const sdk = Sdk.init(b);
     sdk.link(exe, .dynamic);
 
-    exe.addPackage(sdk.getNativePackage("sdl2"));
+    exe.addPackagePath("zgl", "lib/zgl/zgl.zig");
+    exe.addPackage(sdk.getWrapperPackage("sdl2"));
+
+    exe.linkSystemLibrary("gl");
+    exe.linkSystemLibrary("epoxy");
 
     exe.setTarget(target);
     exe.setBuildMode(mode);
diff --git a/lib/zgl b/lib/zgl
new file mode 160000
index 0000000..32608da
--- /dev/null
+++ b/lib/zgl
@@ -0,0 +1 @@
+Subproject commit 32608da70ca057ec09438dbf6549834dcfbeb52c
diff --git a/src/main.zig b/src/main.zig
index a9f0372..fd8cc79 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -1,59 +1,67 @@
 const std = @import("std");
-const SDL = @import("sdl2");
+const sdl = @import("sdl2");
+const gl = @import("zgl");
 
-const Game = @import("Game.zig");
-const MainMenu = @import("MainMenu.zig");
+//const Game = @import("Game.zig");
+//const MainMenu = @import("MainMenu.zig");
 
-const State = @import("flow.zig").State;
+//const State = @import("flow.zig").State;
 
 pub fn main() !void {
-    const stderr = std.io.getStdErr();
-    defer stderr.close();
+    try sdl.init(.{ .video = true, .audio = true, .events = true });
+    defer sdl.quit();
 
-    // var gpa = std.heap.GeneralPurposeAllocator(.{}){};
-    // defer _ = gpa.deinit();
-    // const allocator = gpa.allocator();
+    try sdl.gl.setAttribute(.{ .context_major_version = 2 });
+    try sdl.gl.setAttribute(.{ .context_minor_version = 1 });
 
-    _ = SDL.SDL_Init(SDL.SDL_INIT_VIDEO | SDL.SDL_INIT_EVENTS | SDL.SDL_INIT_AUDIO);
-    defer SDL.SDL_Quit();
-
-    var window = SDL.SDL_CreateWindow(
+    const window = try sdl.createWindow(
         "USG",
-        SDL.SDL_WINDOWPOS_CENTERED,
-        SDL.SDL_WINDOWPOS_CENTERED,
+        .{ .centered = {} },
+        .{ .centered = {} },
         1280,
         720,
-        SDL.SDL_WINDOW_SHOWN,
-    ) orelse return;
-    defer _ = SDL.SDL_DestroyWindow(window);
+        .{ .opengl = true, .shown = true }
+    );
+    defer window.destroy();
 
-    var renderer = SDL.SDL_CreateRenderer(window, -1, SDL.SDL_RENDERER_PRESENTVSYNC | SDL.SDL_RENDERER_ACCELERATED) orelse return;
-    defer _ = SDL.SDL_DestroyRenderer(renderer);
+    const ctx = try sdl.gl.createContext(window);
+    defer sdl.gl.deleteContext(ctx);
 
-    var main_menu = MainMenu.init();
-    var game = Game.init(renderer);
+    //var renderer = SDL.SDL_CreateRenderer(window, -1, SDL.SDL_RENDERER_PRESENTVSYNC | SDL.SDL_RENDERER_ACCELERATED) orelse return;
+    //defer _ = SDL.SDL_DestroyRenderer(renderer);
 
-    var current_state: State = main_menu.state;
+    //var main_menu = MainMenu.init();
+    //var game = Game.init(renderer);
 
-    _ = SDL.SDL_SetRenderDrawBlendMode(renderer, SDL.SDL_BLENDMODE_BLEND);
-    _ = SDL.IMG_Init(SDL.IMG_INIT_JPG);
+    //var current_state: State = main_menu.state;
+
+    //_ = SDL.SDL_SetRenderDrawBlendMode(renderer, SDL.SDL_BLENDMODE_BLEND);
+    //_ = SDL.IMG_Init(SDL.IMG_INIT_JPG);
 
     mainLoop: while (true) {
-        var ev: SDL.SDL_Event = undefined;
-
-        while (SDL.SDL_PollEvent(&ev) != 0) {
-            if (ev.type == SDL.SDL_QUIT)
-                break :mainLoop;
+        while (sdl.pollEvent()) |ev| {
+            switch (ev) {
+                .quit => break :mainLoop,
+                else => {},
+            }
         }
 
-        _ = SDL.SDL_SetRenderDrawColor(renderer, 231, 247, 255, 0xFF);
-        _ = SDL.SDL_RenderClear(renderer);
+        gl.clear(.{});
 
-        current_state = switch (current_state) {
-            .main_menu => main_menu.tick(),
-            .game => game.tick(),
-        };
+        sdl.gl.swapWindow(window);
 
-        SDL.SDL_RenderPresent(renderer);
+        //_ = SDL.SDL_SetRenderDrawColor(renderer, 231, 247, 255, 0xFF);
+        //_ = SDL.SDL_RenderClear(renderer);
+
+        //current_state = switch (current_state) {
+            //.main_menu => main_menu.tick(),
+            //.game => game.tick(),
+        //};
+
+        //SDL.SDL_RenderPresent(renderer);
     }
 }
+
+fn initGL() void {
+
+}