From a94ab87eabce6f97d7a79e49d3f6f2913cc21443 Mon Sep 17 00:00:00 2001
From: Bradlee Speice <bradlee@speice.io>
Date: Sat, 8 Feb 2025 18:39:31 -0500
Subject: [PATCH] Start fixing the camera; use image width for indexing

---
 crates/flare-shader/src/lib.rs | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/crates/flare-shader/src/lib.rs b/crates/flare-shader/src/lib.rs
index d2480fb..ed31d83 100644
--- a/crates/flare-shader/src/lib.rs
+++ b/crates/flare-shader/src/lib.rs
@@ -62,10 +62,11 @@ pub struct CameraConstants {
 
 impl CameraConstants {
     pub fn camera(&self, image_width: i32, image_height: i32) -> glam::Affine2 {
+        let zoom_factor = 2f32.powf(self.zoom);
         let zoom_rotate_offset = glam::Affine2::from_scale_angle_translation(
-            glam::Vec2::splat(2f32.powf(self.zoom)),
+            glam::Vec2::splat(zoom_factor),
             self.rotate.to_radians(),
-            -vec2(self.offset_x, self.offset_y),
+            -vec2(self.offset_x, self.offset_y) * zoom_factor,
         );
         let ifs_to_pixel = glam::Affine2::from_scale_angle_translation(
             glam::Vec2::splat(self.scale),
@@ -262,10 +263,10 @@ pub fn main_cs(
     // Fixed camera, should be provided by a uniform in the future
     let camera = CameraConstants {
         scale: max_dimension as f32 / 4.0,
-        zoom: 0.0,
+        zoom: 2.0,
         rotate: 0.0,
-        offset_x: 0.0,
-        offset_y: 0.0,
+        offset_x: 0.5,
+        offset_y: 0.5,
     }
     .camera(image_constants.accum_width, image_constants.accum_height);
 
@@ -285,7 +286,7 @@ pub fn main_cs(
         let ii = image_index(
             pixel_coordinates.x,
             pixel_coordinates.y,
-            image_constants.accum_height,
+            image_constants.accum_width,
         );
         accum_image[ii as usize] = Color::WHITE;
     }