yog_book/
renderer.rs

1//! Book renderer — ties together yog-ui layout, yog-gfx GPU pipeline,
2//! SVG icon rasterization, and custom font rendering.
3
4use std::collections::HashMap;
5use yog_gfx::{GfxContext, gl, core::{DrawMode, DataType, blend}};
6use yog_ui::{widget, FlexDir, Align, UiRoot};
7
8use crate::{Book, BookPage};
9use crate::state::BookViewState;
10use crate::theme::BookTheme;
11use crate::font::{BookFontRegistry, FontAtlas};
12use crate::svg;
13
14// Patchouli-compatible book texture layout (512×256 sprite sheet).
15// UV coordinates are in pixels on a 512×256 sheet.
16// The full open-book background occupies 272×180 at UV (0,0).
17pub const BOOK_TEX_W: f32   = 512.0;
18pub const BOOK_TEX_H: f32   = 256.0;
19// Open-book dimensions in texture-space
20pub const BK_W: f32         = 272.0;
21pub const BK_H: f32         = 180.0;
22// Per-page dimensions and offsets (in book-local coords)
23pub const PAGE_W: f32       = 116.0;
24pub const PAGE_H: f32       = 156.0;
25pub const TOP_PAD: f32      = 18.0;   // vertical space above page text area
26pub const LEFT_X: f32       = 15.0;   // left page X inside book
27pub const RIGHT_X: f32      = 141.0;  // right page X inside book
28// Separator strip UV origin on the sprite sheet
29pub const SEP_U: f32        = 140.0;
30pub const SEP_V: f32        = 180.0;
31pub const SEP_W: f32        = 110.0;
32pub const SEP_H: f32        = 3.0;
33
34// ── Vertex for the custom 2D shader (pos + uv + color) ───────────────────────
35
36#[repr(C)]
37#[derive(Copy, Clone)]
38struct Vert { x: f32, y: f32, u: f32, v: f32, r: f32, g: f32, b: f32, a: f32 }
39
40fn rgba_f(c: u32) -> (f32, f32, f32, f32) {
41    let a = ((c >> 24) & 0xFF) as f32 / 255.0;
42    let r = ((c >> 16) & 0xFF) as f32 / 255.0;
43    let g = ((c >>  8) & 0xFF) as f32 / 255.0;
44    let b = ( c        & 0xFF) as f32 / 255.0;
45    (r, g, b, a)
46}
47
48fn quad(verts: &mut Vec<Vert>, x: f32, y: f32, w: f32, h: f32,
49        u0: f32, v0: f32, u1: f32, v1: f32, color: u32) {
50    let (r, g, b, a) = rgba_f(color);
51    let p = [
52        Vert { x,        y,        u: u0, v: v0, r, g, b, a },
53        Vert { x: x+w,   y,        u: u1, v: v0, r, g, b, a },
54        Vert { x,        y: y+h,   u: u0, v: v1, r, g, b, a },
55        Vert { x: x+w,   y: y+h,   u: u1, v: v1, r, g, b, a },
56    ];
57    // two triangles: 0,1,2  1,3,2
58    verts.extend_from_slice(&[p[0], p[1], p[2], p[1], p[3], p[2]]);
59}
60
61// ── GLSL shaders ─────────────────────────────────────────────────────────────
62
63const VERT: &str = r#"
64#version 330 core
65layout(location = 0) in vec2 aPos;
66layout(location = 1) in vec2 aUv;
67layout(location = 2) in vec4 aCol;
68out vec2 fUv;
69out vec4 fCol;
70uniform vec2 uScreen;
71void main() {
72    fUv  = aUv;
73    fCol = aCol;
74    vec2 ndc = aPos / uScreen * 2.0 - vec2(1.0);
75    gl_Position = vec4(ndc.x, -ndc.y, 0.0, 1.0);
76}
77"#;
78
79const FRAG: &str = r#"
80#version 330 core
81in vec2 fUv;
82in vec4 fCol;
83out vec4 outColor;
84uniform sampler2D uTex;
85uniform int uMode;  // 0 = solid color, 1 = RGBA texture, 2 = alpha-only (font)
86void main() {
87    if (uMode == 0) {
88        outColor = fCol;
89    } else if (uMode == 1) {
90        outColor = texture(uTex, fUv) * fCol;
91    } else {
92        float alpha = texture(uTex, fUv).a;
93        outColor = vec4(fCol.rgb, fCol.a * alpha);
94    }
95}
96"#;
97
98// ── Embedded textures ─────────────────────────────────────────────────────────
99
100static BOOK_PNG:     &[u8] = include_bytes!("../assets/book_brown.png");
101static CRAFTING_PNG: &[u8] = include_bytes!("../assets/crafting.png");
102
103fn decode_png(data: &[u8]) -> Option<(Vec<u8>, u32, u32)> {
104    use png::Decoder;
105    let decoder = Decoder::new(std::io::Cursor::new(data));
106    let mut reader = decoder.read_info().ok()?;
107    let mut buf = vec![0u8; reader.output_buffer_size()];
108    let info = reader.next_frame(&mut buf).ok()?;
109    let rgba = match info.color_type {
110        png::ColorType::Rgba => buf[..info.buffer_size()].to_vec(),
111        png::ColorType::Rgb  => {
112            let rgb = &buf[..info.buffer_size()];
113            let mut out = Vec::with_capacity(rgb.len() / 3 * 4);
114            for px in rgb.chunks(3) { out.extend_from_slice(px); out.push(255); }
115            out
116        }
117        _ => return None,
118    };
119    Some((rgba, info.width, info.height))
120}
121
122// ── GL resource cache ─────────────────────────────────────────────────────────
123
124struct BookGl {
125    prog:         gl::ShaderProgram,
126    vao:          gl::VertexArray,
127    vbo:          gl::Buffer,
128    book_tex:     Option<(gl::Texture, u32, u32)>,
129    crafting_tex: Option<(gl::Texture, u32, u32)>,
130    svg_tex:      HashMap<u64, (gl::Texture, u32, u32)>,
131    font_atlas:   HashMap<u64, (gl::Texture, FontAtlas)>,
132}
133
134impl BookGl {
135    fn init(ctx: &GfxContext) -> Option<Self> {
136        let prog = ctx.create_shader(VERT, FRAG).ok()?;
137        let vbo  = ctx.create_buffer();
138        let vao  = ctx.create_vao();
139
140        const STRIDE: u32 = 32; // 8 × f32
141        vao.attrib(ctx, &vbo, 0, 2, DataType::F32, false, STRIDE, 0);  // pos
142        vao.attrib(ctx, &vbo, 1, 2, DataType::F32, false, STRIDE, 8);  // uv
143        vao.attrib(ctx, &vbo, 2, 4, DataType::F32, false, STRIDE, 16); // col
144
145        let load = |data: &[u8]| decode_png(data).map(|(rgba, w, h)| {
146            let tex = ctx.create_texture_rgba(w, h, &rgba, true);
147            (tex, w, h)
148        });
149        let book_tex     = load(BOOK_PNG);
150        let crafting_tex = load(CRAFTING_PNG);
151
152        Some(BookGl { prog, vao, vbo, book_tex, crafting_tex, svg_tex: HashMap::new(), font_atlas: HashMap::new() })
153    }
154
155    fn svg_tex(&mut self, ctx: &GfxContext, hash: u64, data: &str, w: u32, h: u32)
156        -> Option<&(gl::Texture, u32, u32)>
157    {
158        if !self.svg_tex.contains_key(&hash) {
159            let pixels = svg::rasterize(data, w, h)?;
160            let tex = ctx.create_texture_rgba(w, h, &pixels, true);
161            self.svg_tex.insert(hash, (tex, w, h));
162        }
163        self.svg_tex.get(&hash)
164    }
165
166    fn flush(&self, ctx: &GfxContext, verts: &[Vert]) {
167        if verts.is_empty() { return; }
168        unsafe { self.vbo.upload(ctx, verts, true); }
169        ctx.draw_arrays(&self.vao, &self.prog, DrawMode::Triangles, 0, verts.len() as u32);
170    }
171}
172
173// ── Draw helpers ──────────────────────────────────────────────────────────────
174
175impl BookGl {
176    fn begin_frame(&self, ctx: &GfxContext, sw: f32, sh: f32) {
177        ctx.set_blend(true, blend::SRC_ALPHA, blend::ONE_MINUS_SRC_ALPHA);
178        ctx.set_depth(false, false);
179        self.prog.uniform_2f(ctx, "uScreen", sw, sh);
180        self.prog.uniform_1i(ctx, "uTex", 0);
181    }
182
183    /// Blit a subrect of a sprite sheet at an arbitrary screen position.
184    fn draw_book_sprite(&self, ctx: &GfxContext, spr: &BgSprite) {
185        let sheet = match spr.sheet {
186            SpriteSheet::Book     => &self.book_tex,
187            SpriteSheet::Crafting => &self.crafting_tex,
188        };
189        let Some((tex, tw, th)) = sheet else { return };
190        let u0 = spr.u  / *tw as f32;
191        let v0 = spr.v  / *th as f32;
192        let u1 = (spr.u + spr.uw) / *tw as f32;
193        let v1 = (spr.v + spr.uh) / *th as f32;
194        self.prog.uniform_1i(ctx, "uMode", 1);
195        ctx.bind_texture(0, tex);
196        let mut v = Vec::with_capacity(6);
197        quad(&mut v, spr.x, spr.y, spr.w, spr.h, u0, v0, u1, v1, 0xFF_FFFFFF);
198        self.flush(ctx, &v);
199    }
200
201    /// Blit the open-book background from the embedded book texture.
202    fn draw_book_bg(&self, ctx: &GfxContext, bx: f32, by: f32, bw: f32, bh: f32) {
203        let Some((tex, tw, th)) = &self.book_tex else { return };
204        let su = BK_W / *tw as f32;
205        let sv = BK_H / *th as f32;
206        self.prog.uniform_1i(ctx, "uMode", 1);
207        ctx.bind_texture(0, tex);
208        let mut v = Vec::with_capacity(6);
209        quad(&mut v, bx, by, bw, bh, 0.0, 0.0, su, sv, 0xFF_FFFFFF);
210        self.flush(ctx, &v);
211    }
212
213    fn draw_svg(&mut self, ctx: &GfxContext, data: &str, x: f32, y: f32, w: f32, h: f32) {
214        let hash = svg::svg_hash(data);
215        let tw = w as u32; let th = h as u32;
216        if let Some(&(tex, _, _)) = self.svg_tex(ctx, hash, data, tw, th) {
217            self.prog.uniform_1i(ctx, "uMode", 1);
218            ctx.bind_texture(0, &tex);
219            let mut v = Vec::with_capacity(6);
220            quad(&mut v, x, y, w, h, 0.0, 0.0, 1.0, 1.0, 0xFF_FFFFFF);
221            self.flush(ctx, &v);
222        }
223    }
224
225    fn draw_text_custom(&mut self, ctx: &GfxContext, ttf: &[u8], size_px: f32,
226                        text: &str, mut x: f32, y: f32, color: u32) {
227        let hash = font_hash(ttf);
228        if !self.font_atlas.contains_key(&hash) {
229            if let Some(atlas) = FontAtlas::build(ttf, size_px) {
230                let tex = ctx.create_texture_rgba(
231                    atlas.atlas_size, atlas.atlas_size, &atlas.pixels, true);
232                self.font_atlas.insert(hash, (tex, atlas));
233            }
234        }
235        // Get raw pointers so the borrow of self.font_atlas ends before we call
236        // self.prog / self.flush, which also borrow fields of self.
237        let ptrs = self.font_atlas.get(&hash)
238            .map(|(t, a)| (t as *const gl::Texture, a as *const FontAtlas));
239        if let Some((tex_ptr, atlas_ptr)) = ptrs {
240            // SAFETY: we hold &mut self; font_atlas is not mutated below.
241            let tex   = unsafe { &*tex_ptr   };
242            let atlas = unsafe { &*atlas_ptr };
243            self.prog.uniform_1i(ctx, "uMode", 2);
244            ctx.bind_texture(0, tex);
245            let baseline = y + size_px;
246            let mut verts = Vec::new();
247            for ch in text.chars() {
248                if let Some(g) = atlas.glyphs.get(&ch) {
249                    if g.width > 0 {
250                        let gx = x + g.xoff;
251                        let gy = baseline - g.yoff - g.height as f32;
252                        quad(&mut verts, gx, gy, g.width as f32, g.height as f32,
253                             g.u0, g.v0, g.u1, g.v1, color);
254                    }
255                    x += g.advance;
256                }
257            }
258            self.flush(ctx, &verts);
259        }
260    }
261}
262
263fn font_hash(data: &[u8]) -> u64 {
264    use std::hash::{Hash, Hasher};
265    let mut h = std::collections::hash_map::DefaultHasher::new();
266    data.hash(&mut h);
267    h.finish()
268}
269
270// ── Background sprite (texture blit, drawn before yog-ui) ────────────────────
271
272#[derive(Clone, Copy, PartialEq)]
273pub(crate) enum SpriteSheet { Book, Crafting }
274
275/// A subrect blit from one of the embedded sprite sheets, drawn before yog-ui.
276#[derive(Clone)]
277pub(crate) struct BgSprite {
278    pub sheet: SpriteSheet,
279    /// Source rect in pixels on the sheet.
280    pub u: f32, pub v: f32, pub uw: f32, pub uh: f32,
281    /// Destination on screen.
282    pub x: f32, pub y: f32, pub w: f32, pub h: f32,
283}
284
285// ── Pending overlay draw commands ─────────────────────────────────────────────
286
287#[derive(Clone)]
288pub(crate) enum OverlayCmd {
289    Svg  { data: String, x: f32, y: f32, w: f32, h: f32 },
290    Text { text: String, font: crate::font::BookFont, x: f32, y: f32, color: u32 },
291}
292
293// ── BookRenderer ──────────────────────────────────────────────────────────────
294
295pub struct BookRenderer {
296    pub book:  Book,
297    pub state: BookViewState,
298    pub theme: BookTheme,
299    fonts:        BookFontRegistry,
300    gl:           Option<BookGl>,
301    pub ui:       Option<UiRoot>,
302    bg_sprites:   Vec<BgSprite>,
303    overlays:     Vec<OverlayCmd>,
304    dirty:   bool,
305    last_sw: f32,
306    last_sh: f32,
307}
308
309impl BookRenderer {
310    pub fn new(book: Book) -> Self {
311        let theme = BookTheme::default().with_nameplate(&book.nameplate_color);
312        Self {
313            book,
314            state: BookViewState::default(),
315            theme,
316            fonts: BookFontRegistry::default(),
317            gl: None,
318            ui: None,
319            bg_sprites: Vec::new(),
320            overlays: Vec::new(),
321            dirty: true,
322            last_sw: 0.0,
323            last_sh: 0.0,
324        }
325    }
326
327    pub fn handle_event(&mut self, ev: &str) {
328        if self.state.handle(ev, &self.book) {
329            self.dirty = true;
330        }
331    }
332
333    /// Register a custom TTF/OTF font for use in `BookPage::CustomText`.
334    pub fn register_font(&mut self, id: impl Into<String>, ttf: Vec<u8>) {
335        self.fonts.register(id, ttf);
336    }
337
338    pub fn render(&mut self, ctx: &GfxContext, sw: f32, sh: f32) {
339        // Lazy GL init.
340        if self.gl.is_none() {
341            self.gl = BookGl::init(ctx);
342        }
343
344        // Compute book rect (same formula as build_ui).
345        let bw = (sw * 0.72).min(BK_W * 2.5);
346        let bh = (sh * 0.80).min(BK_H * 2.5);
347        let bx = (sw - bw) / 2.0;
348        let by = (sh - bh) / 2.0;
349
350        // Rebuild widget tree if dirty or screen resized.
351        if self.dirty || sw != self.last_sw || sh != self.last_sh {
352            let (root, bg_sprites, overlays) = build_ui(&self.book, &self.state, &self.theme, sw, sh, bx, by, bw, bh);
353            self.ui = Some(root);
354            self.bg_sprites = bg_sprites;
355            self.overlays = overlays;
356            self.dirty = false;
357            self.last_sw = sw;
358            self.last_sh = sh;
359        }
360
361        // 1. Draw book background texture first.
362        if let Some(gl) = &mut self.gl {
363            gl.begin_frame(ctx, sw, sh);
364            gl.draw_book_bg(ctx, bx, by, bw, bh);
365        }
366
367        // 1b. Background sprites (nameplate banner, separator lines) from book texture.
368        if let Some(gl) = &mut self.gl {
369            for spr in &self.bg_sprites {
370                gl.draw_book_sprite(ctx, spr);
371            }
372        }
373
374        // 2. yog-ui: text, buttons, icons (transparent BG — texture is already there).
375        if let Some(ui) = &mut self.ui {
376            if ui.needs_layout { ui.layout(sw, sh); }
377            ui.render(ctx);
378        }
379
380        // 3. Custom GL overlays (SVG icons, custom font text).
381        if let Some(gl) = &mut self.gl {
382            gl.begin_frame(ctx, sw, sh);
383            for ov in self.overlays.clone() {
384                match ov {
385                    OverlayCmd::Svg  { data, x, y, w, h } =>
386                        gl.draw_svg(ctx, &data, x, y, w, h),
387                    OverlayCmd::Text { text, font, x, y, color } => {
388                        if let Some(ttf) = self.fonts.get(&font.font_id) {
389                            gl.draw_text_custom(ctx, ttf, font.size_px, &text, x, y, color);
390                        }
391                    }
392                }
393            }
394        }
395    }
396}
397
398// ── UI builder ────────────────────────────────────────────────────────────────
399
400/// Build the yog-ui widget tree + bg sprites + overlay commands for the current book state.
401/// `bx/by/bw/bh` are the screen-space book rect (same values used to blit the bg texture).
402fn build_ui(book: &Book, state: &BookViewState, theme: &BookTheme,
403             sw: f32, sh: f32,
404             bx: f32, by: f32, bw: f32, bh: f32) -> (UiRoot, Vec<BgSprite>, Vec<OverlayCmd>) {
405    let _ = (sw, sh);
406    let mut bg_sprites: Vec<BgSprite> = Vec::new();
407    let mut overlays:   Vec<OverlayCmd> = Vec::new();
408
409    // Scale from Patchouli's fixed BK_W×BK_H coordinate space → actual bw×bh.
410    let sx = bw / BK_W;
411    let sy = bh / BK_H;
412
413    // In book-local: left page starts at x=LEFT_X, right at RIGHT_X, both y=TOP_PAD.
414    let pw = PAGE_W * sx;
415    let ph = PAGE_H * sy;
416    let spine_gap = (RIGHT_X - LEFT_X - PAGE_W) * sx; // ≈10px scaled
417
418    // Content x/y in screen space (for SVG overlay positioning).
419    let lx = bx + LEFT_X  * sx;
420    let rx = bx + RIGHT_X * sx;
421    let py = by + TOP_PAD  * sy;
422
423    if state.at_home {
424        // Nameplate banner: book-local (-8, 12) from LEFT_PAGE_X, size 140×31.
425        bg_sprites.push(BgSprite {
426            sheet: SpriteSheet::Book,
427            u: 0.0, v: 180.0, uw: 140.0, uh: 31.0,
428            x: bx + (LEFT_X - 8.0) * sx,
429            y: by + 12.0 * sy,
430            w: 140.0 * sx,
431            h: 31.0 * sy,
432        });
433        // Separator below "Categories" header on right page (TOP_PAD + 12 book-local)
434        bg_sprites.push(BgSprite {
435            sheet: SpriteSheet::Book,
436            u: SEP_U, v: SEP_V, uw: SEP_W, uh: SEP_H,
437            x: rx,
438            y: by + (TOP_PAD + 12.0) * sy,
439            w: SEP_W * sx,
440            h: (SEP_H * sy).max(1.0),
441        });
442    }
443
444    let (left_page, right_page) = if state.at_home {
445        let l = build_landing_left(book, theme, pw, ph, lx, py, sx, sy);
446        let r = build_categories_right(book, state, theme, pw, ph, rx, py, sx, sy, &mut overlays);
447        (l, r)
448    } else {
449        let l = build_entry_left(book, state, theme, pw, ph, lx, py, sx, sy, &mut bg_sprites, &mut overlays);
450        let r = build_entries_right(book, state, theme, pw, ph, rx, py, sx, sy);
451        (l, r)
452    };
453
454    // Root row spans the full book width.
455    // padding-left = LEFT_X*sx offsets both pages from the left cover edge.
456    // padding-top  = TOP_PAD*sy offsets from the header banner.
457    // spine_gap spacer sits between the two pages.
458    let root_widget = widget::panel(FlexDir::Row)
459        .w(bw).h(bh)
460        .padding(TOP_PAD * sy, 0.0, 0.0, LEFT_X * sx)
461        .child(left_page)
462        .child(widget::spacer().w(spine_gap))  // spine gap
463        .child(right_page);
464
465    // Outer shell: positions the book on screen via a full-screen transparent Row.
466    // We use a Column + Row arrangement to apply top/left offsets without margin support.
467    let outer = widget::panel(FlexDir::Column)
468        .w(bw).h(bh)
469        .child(root_widget);
470
471    // Screen-level container: positions book at (bx, by).
472    // bx offset via padding, by offset via padding-top.
473    // Note: layout computes from (0,0), so we pass bx/by into the UiRoot manually
474    // by wrapping in a full-screen panel with the right padding.
475    let screen_root = widget::panel(FlexDir::Row)
476        .padding(by, 0.0, 0.0, bx)
477        .child(outer);
478
479    let ui = UiRoot::new(&book.id, screen_root);
480    (ui, bg_sprites, overlays)
481}
482
483// ── Left page: landing (home view) ───────────────────────────────────────────
484
485fn build_landing_left(book: &Book, theme: &BookTheme,
486                       page_w: f32, page_h: f32, _lx: f32, _py: f32,
487                       _sx: f32, sy: f32)
488    -> widget::Widget
489{
490    // The nameplate banner occupies book-local y=12..43.
491    // Page area starts at y=TOP_PAD=18 → visible banner in page-widget: y=0..(43-18)*sy.
492    let nameplate_h = (43.0 - TOP_PAD) * sy;
493    let gap         = 4.0;
494    let pad_top     = 2.0;
495
496    let mut col = widget::panel(FlexDir::Column)
497        .w(page_w).h(page_h)
498        .padding(pad_top, 6.0, 4.0, 4.0)
499        .gap(gap);
500
501    // Book title on nameplate sprite.
502    col = col.child(widget::label(&book.name).color(theme.nameplate).h(10.0));
503
504    // Optional author subtitle ("by …") — mirrors Patchouli's subtitle field.
505    let spacer_h = if let Some(author) = &book.author {
506        col = col.child(
507            widget::label(format!("by {}", author)).color(theme.nameplate).h(8.0)
508        );
509        (nameplate_h - 10.0 - gap - 8.0 - gap).max(0.0)
510    } else {
511        (nameplate_h - 10.0 - gap).max(0.0)
512    };
513    col = col.child(widget::spacer().h(spacer_h));
514
515    // Landing text paragraphs.
516    for para in book.landing_text.split('\n') {
517        if para.is_empty() {
518            col = col.child(widget::spacer().h(3.0));
519        } else {
520            col = col.child(widget::label(para).color(theme.text));
521        }
522    }
523
524    // Progress bar at bottom: entry count across all categories.
525    let total = book.entries.len();
526    col = col.child(widget::spacer().flex(1.0));
527    col = col.child(
528        widget::spacer().h(3.0).bg(theme.border)   // thin separator line
529    );
530    col = col.child(
531        widget::label(format!("{} entries", total))
532            .color(theme.nav).h(9.0).align(Align::Center)
533    );
534    col
535}
536
537// ── Right page: category list (home view) ────────────────────────────────────
538
539fn build_categories_right(
540    book: &Book, state: &BookViewState, theme: &BookTheme,
541    page_w: f32, page_h: f32,
542    _rx: f32, _py: f32,
543    sx: f32, sy: f32,
544    overlays: &mut Vec<OverlayCmd>,
545) -> widget::Widget {
546    let _ = overlays;
547
548    // Patchouli right-page layout (landing):
549    //   "Categories" header at TOP_PADDING, centered over RIGHT_PAGE_X..RIGHT_PAGE_X+PAGE_WIDTH
550    //   Separator at TOP_PADDING+12 (drawn as bg sprite, not here)
551    //   4-column 24×24 icon grid starting at (RIGHT_PAGE_X+10, TOP_PADDING+25)
552    //   In page-local terms: left-pad=10, top-pad=(TOP_PAD+25-TOP_PAD)=25, cell=24
553    let cell_w = 24.0 * sx;
554    let cell_h = 24.0 * sy;
555    let grid_pad_left = 10.0 * sx;
556    // TOP_PADDING+12 is where separator is; TOP_PADDING+25 is where the grid starts.
557    // In page-widget space (y=0 = book-local TOP_PAD): grid starts at 25*sy.
558    let grid_top = 25.0 * sy;
559    // Space above grid = grid_top (separator region = 12*sy to 25*sy)
560    let header_h  = 12.0 * sy; // "Categories" label
561    let sep_gap   = (grid_top - header_h).max(0.0); // gap between label and grid
562
563    let mut col = widget::panel(FlexDir::Column)
564        .w(page_w).h(page_h)
565        .padding(0.0, 4.0, 4.0, 0.0)
566        .gap(0.0);
567
568    // Header: "Categories" centered
569    col = col.child(
570        widget::label("Categories").color(theme.divider).h(header_h)
571    );
572    // Gap where the separator sprite sits
573    col = col.child(widget::spacer().h(sep_gap));
574
575    // 4-column icon grid
576    let cats = &book.categories;
577    let mut row_i = 0usize;
578    loop {
579        let row_start = row_i * 4;
580        if row_start >= cats.len() { break; }
581        let mut row = widget::panel(FlexDir::Row)
582            .h(cell_h)
583            .gap(0.0)
584            .padding(0.0, 0.0, 0.0, grid_pad_left);
585        for col_i in 0..4 {
586            let idx = row_start + col_i;
587            if idx >= cats.len() { break; }
588            let cat = &cats[idx];
589            let selected = !state.at_home && idx == state.cat;
590            let bg = if selected { theme.nav_selected_bg } else { 0 };
591
592            let icon_w = 16.0 * sx;
593            let icon_h = 16.0 * sy;
594            let pad_xy = (cell_w - icon_w) / 2.0;
595
596            let mut cell = widget::panel(FlexDir::Column)
597                .w(cell_w).h(cell_h).bg(bg)
598                .on_click(format!("cat:{}", idx))
599                .id(format!("book_cat_{}", idx))
600                .padding(pad_xy, pad_xy, pad_xy, pad_xy);
601            cell = if let Some(icon_id) = &cat.icon {
602                cell.child(item_icon_widget(icon_id).w(icon_w).h(icon_h))
603            } else {
604                cell.child(widget::spacer().w(icon_w).h(icon_h))
605            };
606            row = row.child(cell);
607        }
608        col = col.child(row);
609        row_i += 1;
610    }
611    col
612}
613
614// ── Left page: entry content (entry view) ────────────────────────────────────
615
616fn build_entry_left(
617    book: &Book, state: &BookViewState, theme: &BookTheme,
618    page_w: f32, page_h: f32,
619    ox: f32, oy: f32,
620    sx: f32, sy: f32,
621    bg_sprites: &mut Vec<BgSprite>,
622    overlays: &mut Vec<OverlayCmd>,
623) -> widget::Widget {
624    let entry      = state.current_entry(book);
625    let page       = entry.and_then(|e| e.pages.get(state.page));
626    let page_count = state.page_count(book);
627    let title_text = entry.map(|e| e.name.as_str()).unwrap_or("");
628
629    // Sprite separator after title.
630    // Layout: padding-top=4, title h=14, gap=3 → separator at oy+21.
631    let pad_top  = 4.0;
632    let title_h  = 14.0;
633    let gap      = 3.0;
634    let sep_h_px = (SEP_H * sy).max(2.0);
635    let sep_y    = oy + pad_top + title_h + gap;
636    bg_sprites.push(BgSprite {
637        sheet: SpriteSheet::Book,
638        u: SEP_U, v: SEP_V, uw: SEP_W, uh: SEP_H,
639        x: ox, y: sep_y,
640        w: SEP_W * sx, h: sep_h_px,
641    });
642
643    // Body starts after separator + another gap.
644    let body_oy = sep_y + sep_h_px + gap;
645
646    let page_label = format!("{}/{}", state.page + 1, page_count);
647    let nav = widget::panel(FlexDir::Row)
648        .h(16.0).gap(4.0)
649        .padding(0.0, 2.0, 0.0, 2.0)
650        .child(widget::button("◀").w(16.0).h(12.0).color(theme.nav)
651            .on_click("prev_page").id("prev_page"))
652        .child(widget::label(&page_label).color(theme.nav).flex(1.0).align(Align::Center))
653        .child(widget::button("⌂").w(16.0).h(12.0).color(theme.nav)
654            .on_click("home").id("book_home"))
655        .child(widget::button("▶").w(16.0).h(12.0).color(theme.nav)
656            .on_click("next_page").id("next_page"));
657
658    let page_body = build_page(page, state.page, theme, bg_sprites, overlays, ox, body_oy, sx, sy);
659
660    widget::panel(FlexDir::Column)
661        .w(page_w).h(page_h)
662        .padding(pad_top, 6.0, 4.0, 4.0)
663        .gap(gap)
664        .child(widget::label(title_text).color(theme.title).h(title_h).align(Align::Center))
665        .child(widget::spacer().h(sep_h_px))   // space for sprite separator
666        .child(page_body)
667        .child(nav)
668}
669
670// ── Right page: entry list for selected category (entry view) ─────────────────
671
672fn build_entries_right(
673    book: &Book, state: &BookViewState, theme: &BookTheme,
674    page_w: f32, page_h: f32, _rx: f32, _py: f32,
675    _sx: f32, _sy: f32,
676) -> widget::Widget {
677    let entries  = state.entries_visible(book);
678    let cat_name = book.categories.get(state.cat).map(|c| c.name.as_str()).unwrap_or("Entries");
679    let spread_count = state.list_spread_count(book);
680
681    let mut col = widget::panel(FlexDir::Column)
682        .w(page_w).h(page_h)
683        .padding(4.0, 6.0, 4.0, 4.0)
684        .gap(1.0);
685
686    col = col.child(widget::label(cat_name).color(theme.divider).h(11.0));
687    col = col.child(widget::spacer().h(2.0));
688
689    let abs_start = state.list_spread_start();
690    for (i, entry) in entries.iter().enumerate() {
691        let abs_i    = abs_start + i;
692        let selected = abs_i == state.entry;
693        let bg    = if selected { theme.nav_selected_bg } else { 0 };
694        let color = if selected { theme.nav_selected } else { theme.nav };
695
696        let mut row = widget::panel(FlexDir::Row)
697            .h(14.0).gap(4.0).bg(bg)
698            .on_click(format!("entry:{}", abs_i))
699            .id(format!("book_entry_{}", abs_i))
700            .padding(1.0, 2.0, 1.0, 2.0);
701
702        if let Some(icon_id) = &entry.icon {
703            row = row.child(item_icon_widget(icon_id));
704        } else {
705            row = row.child(widget::spacer().w(14.0));
706        }
707        row = row.child(widget::label(&entry.name).color(color).flex(1.0));
708        col = col.child(row);
709    }
710
711    // List spread navigation — only shown when there's more than one spread.
712    if spread_count > 1 {
713        col = col.child(widget::spacer().flex(1.0));
714        let spread_label = format!("{}/{}", state.list_spread + 1, spread_count);
715        col = col.child(
716            widget::panel(FlexDir::Row).h(14.0).gap(2.0)
717                .child(widget::button("◀").w(14.0).h(12.0).color(theme.nav)
718                    .on_click("prev_list").id("prev_list"))
719                .child(widget::label(&spread_label).color(theme.nav)
720                    .flex(1.0).align(Align::Center))
721                .child(widget::button("▶").w(14.0).h(12.0).color(theme.nav)
722                    .on_click("next_list").id("next_list"))
723        );
724    }
725    col
726}
727
728/// Bare 16×16 item icon widget from an item ID ("ns:item_name" or "ns:item/name").
729fn item_icon_widget(item_id: &str) -> widget::Widget {
730    // Normalize "ns:item/name" or "ns:block/name" → "ns:textures/item/name.png"
731    // Normalize "ns:name" → "ns:textures/item/name.png"
732    let tex = if let Some((ns, path)) = item_id.split_once(':') {
733        if path.starts_with("item/") || path.starts_with("block/") {
734            format!("{ns}:textures/{path}.png")
735        } else {
736            format!("{ns}:textures/item/{path}.png")
737        }
738    } else {
739        format!("minecraft:textures/item/{item_id}.png")
740    };
741    widget::mc_image(&tex, 16.0, 16.0)
742}
743
744// ── Page content builder ──────────────────────────────────────────────────────
745
746/// Build the content widget for a single page.
747/// `ox/oy` = screen top-left of the page body area.
748/// `sx/sy` = book-local-to-screen scale factors.
749fn build_page(
750    page: Option<&BookPage>,
751    page_num: usize,
752    theme: &BookTheme,
753    bg_sprites: &mut Vec<BgSprite>,
754    overlays: &mut Vec<OverlayCmd>,
755    ox: f32, oy: f32,
756    sx: f32, sy: f32,
757) -> widget::Widget {
758    let mut col = widget::panel(FlexDir::Column).flex(1.0).gap(4.0);
759
760    let Some(page) = page else {
761        return col.child(widget::label("No entries yet.").color(theme.nav));
762    };
763
764    match page {
765        BookPage::Text { text, title } => {
766            // On non-first pages, show an optional section title + separator.
767            if page_num > 0 {
768                if let Some(t) = title {
769                    let sep_h_px = (SEP_H * sy).max(2.0);
770                    col = col.child(widget::label(t.as_str()).color(theme.title)
771                        .h(12.0).align(Align::Center));
772                    bg_sprites.push(BgSprite {
773                        sheet: SpriteSheet::Book,
774                        u: SEP_U, v: SEP_V, uw: SEP_W, uh: SEP_H,
775                        x: ox, y: oy + 12.0 + 3.0,
776                        w: SEP_W * sx, h: sep_h_px,
777                    });
778                    col = col.child(widget::spacer().h(sep_h_px));
779                }
780            }
781            for para in text.split('\n') {
782                col = col.child(widget::label(para).color(theme.text));
783            }
784        }
785
786        BookPage::Spotlight { item, title, text } => {
787            // Crafting-box frame from crafting.png sprite sheet.
788            // Source: u=0, v=102 (=128-26), w=66, h=26 on 128×256 sheet.
789            // Destination (page-body-local): x = PAGE_W/2 - 33 = 25, y = 10.
790            let box_w   = 66.0 * sx;
791            let box_h   = 26.0 * sy;
792            let box_x   = ox + (PAGE_W / 2.0 - 33.0) * sx;
793            let box_y   = oy + 10.0 * sy;
794            bg_sprites.push(BgSprite {
795                sheet: SpriteSheet::Crafting,
796                u: 0.0, v: 102.0, uw: 66.0, uh: 26.0,
797                x: box_x, y: box_y, w: box_w, h: box_h,
798            });
799
800            // Item title above the box (page-body y=0).
801            let item_name = title.as_deref()
802                .or(item.name.as_deref())
803                .unwrap_or(item.id.as_str());
804            col = col.child(widget::label(item_name).color(theme.title)
805                .h(10.0).align(Align::Center));
806
807            // Spacer to box top (y=10 book-local) minus title.
808            col = col.child(widget::spacer().h((10.0 * sy - 10.0 - 4.0).max(0.0)));
809
810            // Item icon centered in box (page-body y=15, x=PAGE_W/2-8).
811            let icon_size = 16.0 * sx.min(sy);
812            col = col.child(
813                widget::panel(FlexDir::Row).h(icon_size)
814                    .child(widget::spacer().flex(1.0))
815                    .child(item_icon_widget(&item.id).w(icon_size).h(icon_size))
816                    .child(widget::spacer().flex(1.0))
817            );
818
819            // Spacer for the rest of the box below the icon.
820            let icon_end = 15.0 * sy + icon_size;
821            let box_end  = 10.0 * sy + box_h;
822            col = col.child(widget::spacer().h((box_end - icon_end + 4.0).max(0.0)));
823
824            if let Some(t) = text {
825                col = col.child(widget::label(t.as_str()).color(theme.text));
826            }
827        }
828
829        BookPage::Crafting { recipe_id, text } => {
830            col = col.child(
831                widget::label(format!("[Crafting: {}]", recipe_id)).color(theme.nav)
832            );
833            if let Some(t) = text {
834                col = col.child(widget::label(t.as_str()).color(theme.text));
835            }
836        }
837
838        BookPage::Smelting { recipe_id, text } => {
839            col = col.child(
840                widget::label(format!("[Smelting: {}]", recipe_id)).color(theme.nav)
841            );
842            if let Some(t) = text {
843                col = col.child(widget::label(t.as_str()).color(theme.text));
844            }
845        }
846
847        BookPage::Image { texture, title, text, .. } => {
848            if let Some(t) = title {
849                col = col.child(widget::label(t.as_str()).color(theme.title));
850            }
851            col = col.child(widget::mc_image(texture, 80.0, 80.0));
852            if let Some(t) = text {
853                col = col.child(widget::label(t.as_str()).color(theme.text));
854            }
855        }
856
857        BookPage::Svg { data, title, text } => {
858            if let Some(t) = title {
859                col = col.child(widget::label(t.as_str()).color(theme.title));
860            }
861            overlays.push(OverlayCmd::Svg { data: data.clone(), x: ox, y: oy, w: 64.0, h: 64.0 });
862            col = col.child(widget::spacer().h(68.0));
863            if let Some(t) = text {
864                col = col.child(widget::label(t.as_str()).color(theme.text));
865            }
866        }
867
868        BookPage::CustomText { text, font, color } => {
869            overlays.push(OverlayCmd::Text {
870                text: text.clone(), font: font.clone(), x: ox, y: oy, color: *color,
871            });
872            col = col.child(widget::spacer().h(font.size_px * 1.5));
873        }
874
875        BookPage::Relations { entries, text } => {
876            if let Some(t) = text {
877                col = col.child(widget::label(t.as_str()).color(theme.text));
878            }
879            col = col.child(widget::label("See also:").color(theme.title));
880            for e in entries {
881                col = col.child(widget::label(format!("• {}", e)).color(theme.nav));
882            }
883        }
884
885        BookPage::Entity { entity_type, name, text } => {
886            let display = name.as_deref().unwrap_or(entity_type.as_str());
887            col = col.child(widget::label(display).color(theme.title));
888            if let Some(t) = text {
889                col = col.child(widget::label(t.as_str()).color(theme.text));
890            }
891        }
892
893        BookPage::Pattern { op_id, input, output, text, .. } => {
894            col = col.child(widget::label(op_id.as_str()).color(theme.title));
895            col = col.child(
896                widget::label(format!("{} → {}", input, output)).color(theme.nav)
897            );
898            if !text.is_empty() {
899                col = col.child(widget::label(text.as_str()).color(theme.text));
900            }
901        }
902
903        BookPage::Empty => {}
904    }
905
906    col
907}
yog_book/renderer.rs

yog_book/
renderer.rs
