From 487434a0b55fa7cf479f39481b51da0a7eda79e1 Mon Sep 17 00:00:00 2001
From: Gabriel Schneider <gbrls@0x4200.cafe>
Date: Sun, 2 Aug 2026 13:13:53 -0300
Subject: gui: draw image surfaces as GPU quads via glsl shaders

---
 src/pardes.zig | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

(limited to 'src/pardes.zig')

diff --git a/src/pardes.zig b/src/pardes.zig
index 0c7c0363..956b0e25 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -391,9 +391,12 @@ pub const Cell = struct {
 };
 
 /// A pixel image riding the surface: the shell transmits/places it over the
-/// given cell rect (tty: kitty graphics; SDL: texture blit).
+/// given cell rect (tty: Kitty graphics; SDL: alpha-blended GPU texture).
 pub const ImagePlace = struct {
-    pane: u8, // stable key for the shell's transmit-once cache
+    pane: u8, // cache slot
+    /// Pane slots are reused. This generation makes a cached GPU texture or
+    /// kitty image unambiguously belong to the pane which supplied the bytes.
+    serial: u32,
     x: u16,
     y: u16,
     w: u16,
@@ -1172,9 +1175,10 @@ pub const Pardes = struct {
     /// the Crt builtin's CRT post-process, rendered by the gui shell only
     /// (the tty and web shells never read it)
     crt_on: bool = false,
-    /// kitty graphics support, reported by the shell (image panes fall back
-    /// to the petscii matcher without it)
-    kitty_ok: bool = false,
+    /// Native pixel attachments supported by the shell (Kitty graphics in a
+    /// terminal, GPU textures in SDL). Image panes dynamically fall back to
+    /// the PETSCII matcher without it.
+    native_images: bool = false,
     quit: bool = false,
     drag: Drag = .none,
     hover_col: u16 = 0,
@@ -1260,7 +1264,7 @@ pub const Pardes = struct {
             // FILE argv boot: the doc focused in the left column, a terminal
             // on the launch directory in the right (files left, shells right)
             _ = if (look.isImagePath(path))
-                try p.openImageView(0, path, !p.kitty_ok)
+                try p.openImageView(0, path)
             else
                 try file_pane.open(p, 0, path, opts.file_line);
             const sh = try p.newPane(1);
@@ -6250,11 +6254,15 @@ pub const Pardes = struct {
         return pane;
     }
 
-    fn openImageView(p: *Pardes, id: usize, path: []const u8, petscii: bool) !*Pane {
+    fn openImageView(p: *Pardes, id: usize, path: []const u8) !*Pane {
         const path_copy = try p.gpa.dupe(u8, path);
         errdefer p.gpa.free(path_copy);
         const pane = try p.newDocPane(id);
-        pane.image = .{ .path = path_copy, .petscii = petscii };
+        // Native pixels are the preference, not a capability observed at open
+        // time. drawImage dynamically falls back while a shell has no native
+        // image support; this matters because kitty detection finishes after
+        // argv images and restored panes have already been constructed.
+        pane.image = .{ .path = path_copy };
         return pane;
     }
 
@@ -6489,8 +6497,7 @@ pub const Pardes = struct {
             .image => |target| {
                 if (p.focusPaneByPath(target.path, .{})) return;
                 const free = p.freeSlot() orelse return;
-                // petscii by default when the host has no kitty graphics
-                const nt = p.openImageView(free, target.path, !p.kitty_ok) catch return;
+                const nt = p.openImageView(free, target.path) catch return;
                 p.placeDoc(id, free, nt);
             },
         }
@@ -6866,7 +6873,7 @@ pub const Pardes = struct {
                         dump.decodeBytes(gpa, im.bytes_b64) catch &.{}
                     else
                         &.{};
-                    pane.image = .{ .path = path, .petscii = true, .raw = raw };
+                    pane.image = .{ .path = path, .raw = raw };
                     pane.cols = @max(1, src.cols);
                     pane.rows = @max(1, src.rows);
                 },
@@ -7553,12 +7560,13 @@ pub const Pardes = struct {
         if (iv.rgba.len == 0 or r.h <= BOX_H) return;
         const body_cols = tw;
         const body_rows = r.h - BOX_H;
-        const use_petscii = iv.petscii or !p.kitty_ok;
+        const use_petscii = iv.petscii or !p.native_images;
         if (!use_petscii) {
             s.images[s.nimages] = .{
                 .pane = @intCast(for (p.panes, 0..) |slot, i| {
                     if (slot == pane) break i;
                 } else 0),
+                .serial = pane.serial,
                 .x = tx,
                 .y = r.y + BOX_H,
                 .w = body_cols,
-- 
cgit v1.3