renderer/opengl: resize the screen texture

src/renderer/opengl/custom.zig

@@ -148,6 +148,19 @@ pub const State = struct {
             1,
         };
         try self.syncUniforms();
+
+        // Update our texture
+        const texbind = try self.fb_texture.bind(.@"2D");
+        try texbind.image2D(
+            0,
+            .rgb,
+            @intCast(size.width),
+            @intCast(size.height),
+            0,
+            .rgb,
+            .UnsignedByte,
+            null,
+        );
     }
 
     /// Call this prior to drawing a frame to update the time

src/renderer/shaders/shadertoy_prefix.glsl

@@ -13,7 +13,7 @@ layout(binding = 0) uniform Globals {
     uniform float	iSampleRate;
 };
 
-layout(binding = 1) uniform sampler2D	iChannel0;
+layout(binding = 0) uniform sampler2D	iChannel0;
 
 // These are unused currently by Ghostty:
 // layout(binding = 1) uniform sampler2D	iChannel1;