From e56efe809ba0f3c47feaecedd992e10f4209a451 Mon Sep 17 00:00:00 2001
From: s-ol <s+removethis@s-ol.nu>
Date: Wed, 10 Nov 2021 16:19:21 +0100
Subject: resolve '#pragma include "...path..."' directives

---
 src/main.zig | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 53 insertions(+), 8 deletions(-)

(limited to 'src')

diff --git a/src/main.zig b/src/main.zig
index b580dd9..47e72f8 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -104,7 +104,7 @@ pub fn main() !void {
 
     const shader_file = try fs.cwd().openFile(config.fragment, .{});
     var last_stat = try shader_file.stat();
-    try reloadShader(&main_program, shader_file, last_stat.size);
+    try reloadShader(&main_program, shader_file, config.fragment, last_stat.size);
 
     var cache = gl.UniformCache.init(std.heap.c_allocator, &main_program);
     defer cache.deinit();
@@ -112,8 +112,6 @@ pub fn main() !void {
     const control = try ctrl.ControlServer.init(&arena.allocator, config.osc, &cache);
     defer control.destroy();
 
-    _ = try cache.get("radius\x00");
-
     while (c.glfwWindowShouldClose(window) == c.GL_FALSE) {
         c.glfwMakeContextCurrent(window);
         c.glClear(c.GL_COLOR_BUFFER_BIT);
@@ -124,7 +122,7 @@ pub fn main() !void {
 
         const stat = try shader_file.stat();
         if (stat.mtime > last_stat.mtime) {
-            try reloadShader(&main_program, shader_file, stat.size);
+            try reloadShader(&main_program, shader_file, config.fragment, stat.size);
             try cache.refresh();
             last_stat = stat;
         }
@@ -154,11 +152,58 @@ pub fn main() !void {
     }
 }
 
-fn reloadShader(current: *gl.ShaderProgram, frag_file: fs.File, size: u64) !void {
-    var frag_source = try c_allocator.alloc(u8, @intCast(usize, size));
+// given a file and the directory it is in, resolve references
+fn loadFile(writer: anytype, dir: []const u8, filename: []const u8) !void {
+    const file_dir = try std.fs.path.resolve(c_allocator, &[_][]const u8{
+        dir,
+        std.fs.path.dirname(filename) orelse "",
+    });
+    defer c_allocator.free(file_dir);
+
+    const file_path = try std.fs.path.resolve(c_allocator, &[_][]const u8{ dir, filename });
+    defer c_allocator.free(file_path);
+
+    var file = try fs.openFileAbsolute(file_path, .{});
+    defer file.close();
+    var reader = file.reader();
+
+    var buf: [1024]u8 = undefined;
+    while (try reader.readUntilDelimiterOrEof(&buf, '\n')) |line| {
+        if (std.mem.startsWith(u8, line, "#pragma ")) {
+            var parts = std.mem.split(line, " ");
+            _ = parts.next();
+            const pragma = parts.next().?;
+
+            if (std.mem.eql(u8, pragma, "include")) {
+                var include_path = parts.next().?;
+                if (include_path[0] != '"' or include_path[include_path.len - 1] != '"') {
+                    std.debug.warn("Invalid #pragma directive '{}'\n", .{line});
+                    continue;
+                }
+                include_path = include_path[1 .. include_path.len - 1];
+
+                loadFile(writer, file_dir, include_path) catch unreachable;
+
+                continue;
+            } else {
+                std.debug.warn("Unknown #pragma directive '{}'\n", .{pragma});
+            }
+        }
+
+        _ = try writer.write(line);
+        _ = try writer.write("\n");
+    }
+}
+
+fn reloadShader(current: *gl.ShaderProgram, frag_file: fs.File, frag_filename: []const u8, size: u64) !void {
+    var buffer = try std.ArrayList(u8).initCapacity(c_allocator, @intCast(usize, size));
+    var writer = buffer.writer();
+    errdefer buffer.deinit();
+
+    try loadFile(buffer.writer(), "", frag_filename);
+
+    const frag_source = buffer.toOwnedSlice();
     defer c_allocator.free(frag_source);
-    try frag_file.seekTo(0);
-    const length = try frag_file.read(frag_source);
 
     const vert_source =
         \\#version 330 core
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