Add a CRT shader effect over the game.

src/game.odin

@@ -26,6 +26,7 @@ RESOLUTIONS := [?]Resolution{
 Game :: struct {
     viewport:     rl.RenderTexture2D,
     bg_texture:   rl.Texture2D, 
+    crt_shader:   rl.Shader,
     scene_stack:  [dynamic]Scene,
     should_close: bool,
     audio:        Audio_Manager,
@@ -65,8 +66,8 @@ game_init :: proc(game: ^Game) {
     game.scene_stack = make([dynamic]Scene, 0, 8)
     game.viewport = rl.LoadRenderTexture(VIEWPORT_W, VIEWPORT_H)
 
-    // Force nearest neighbor point filtering on the viewport texture
-    rl.SetTextureFilter(game.viewport.texture, .POINT)
+    // Look into texture filters
+    rl.SetTextureFilter(game.viewport.texture, .BILINEAR)
 
     // Generate soft CRT background radial texture once on startup
     bg_center := rl.Color{22, 28, 36, 255}
@@ -74,7 +75,8 @@ game_init :: proc(game: ^Game) {
     bg_img    := rl.GenImageGradientRadial(VIEWPORT_W, VIEWPORT_H, 0.3, bg_center, bg_corner)
     game.bg_texture = rl.LoadTextureFromImage(bg_img)
     rl.UnloadImage(bg_img) // Free CPU memory
-    // rl.SetTextureFilter(game.bg_texture, .BILINEAR)
+
+    game.crt_shader = rl.LoadShader(nil, "assets/shaders/crt.fs")
 
     game.should_close = false
     set_root_scene(game, make_main_menu()) 
@@ -121,6 +123,7 @@ game_render :: proc(game: ^Game) {
 game_quit :: proc(game: ^Game) {
     audio_manager_quit(&game.audio)
 
+    rl.UnloadShader(game.crt_shader)
     rl.UnloadTexture(game.bg_texture)
     rl.UnloadRenderTexture(game.viewport)
     delete(GLOBAL_EVENTS)
@@ -156,15 +159,16 @@ game_set_resolution :: proc(game: ^Game, res_index: int) {
 render_game_to_window :: proc(game: ^Game) {
     texture := game.viewport.texture
 
-    rl.DrawTexturePro(
-        texture, 
-        // src: inverted y coordinate flips opengl texture buffer correctly
-        rl.Rectangle{0, 0, f32(texture.width), -f32(texture.height)},
-        // dst: scales viewport canvas to fill window resolution
-        rl.Rectangle{0, 0, f32(game.window_w), f32(game.window_h)},
-        rl.Vector2{},
-        0,
-        rl.WHITE,
-    ) 
-
+    rl.BeginShaderMode(game.crt_shader)
+        rl.DrawTexturePro(
+            texture, 
+            // src: inverted y coordinate flips opengl texture buffer correctly
+            rl.Rectangle{0, 0, f32(texture.width), -f32(texture.height)},
+            // dst: scales viewport canvas to fill window resolution
+            rl.Rectangle{0, 0, f32(game.window_w), f32(game.window_h)},
+            rl.Vector2{},
+            0,
+            rl.WHITE,
+        ) 
+    rl.EndShaderMode()
 }