1use crate::{
2 prelude::*, AlphaType, Color, Color4f, ColorSpace, ColorType, IPoint, IRect, ISize, ImageInfo,
3 SamplingOptions,
4};
5use skia_bindings::{self as sb, SkPixmap};
6use std::{ffi::c_void, fmt, marker::PhantomData, mem, os::raw, ptr, slice};
7
8#[repr(transparent)]
9pub struct Pixmap<'a> {
10 inner: Handle<SkPixmap>,
11 pd: PhantomData<&'a mut [u8]>,
12}
13
14impl NativeDrop for SkPixmap {
15 fn drop(&mut self) {
16 unsafe { sb::C_SkPixmap_destruct(self) }
17 }
18}
19
20impl Default for Pixmap<'_> {
21 fn default() -> Self {
22 Self::from_native_c(pixmap:SkPixmap {
23 fPixels: ptr::null(),
24 fRowBytes: 0,
25 fInfo: construct(|ii: *mut SkImageInfo| unsafe { sb::C_SkImageInfo_Construct(uninitialized:ii) }),
26 })
27 }
28}
29
30impl fmt::Debug for Pixmap<'_> {
31 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
32 f&mut DebugStruct<'_, '_>.debug_struct("Pixmap")
33 .field("row_bytes", &self.row_bytes())
34 .field(name:"info", self.info())
35 .finish()
36 }
37}
38
39impl<'pixels> Pixmap<'pixels> {
40 pub fn new(info: &ImageInfo, pixels: &'pixels mut [u8], row_bytes: usize) -> Option<Self> {
41 if row_bytes < info.min_row_bytes() {
42 return None;
43 }
44 if pixels.len() < info.compute_byte_size(row_bytes) {
45 return None;
46 }
47
48 Some(Pixmap::from_native_c(SkPixmap {
49 fPixels: pixels.as_mut_ptr() as _,
50 fRowBytes: row_bytes,
51 fInfo: info.native().clone(),
52 }))
53 }
54
55 pub fn reset(&mut self) -> &mut Self {
56 unsafe { self.native_mut().reset() }
57 self
58 }
59
60 // TODO: reset() function that re-borrows pixels?
61
62 pub fn set_color_space(&mut self, color_space: impl Into<Option<ColorSpace>>) -> &mut Self {
63 unsafe {
64 sb::C_SkPixmap_setColorSpace(self.native_mut(), color_space.into().into_ptr_or_null())
65 }
66 self
67 }
68
69 #[must_use]
70 pub fn extract_subset(&self, area: impl AsRef<IRect>) -> Option<Self> {
71 let mut pixmap = Pixmap::default();
72 unsafe {
73 self.native()
74 .extractSubset(pixmap.native_mut(), area.as_ref().native())
75 }
76 .if_true_some(pixmap)
77 }
78
79 pub fn info(&self) -> &ImageInfo {
80 ImageInfo::from_native_ref(&self.native().fInfo)
81 }
82
83 pub fn row_bytes(&self) -> usize {
84 self.native().fRowBytes
85 }
86
87 pub fn addr(&self) -> *const c_void {
88 self.native().fPixels
89 }
90
91 pub fn width(&self) -> i32 {
92 self.info().width()
93 }
94
95 pub fn height(&self) -> i32 {
96 self.info().height()
97 }
98
99 pub fn dimensions(&self) -> ISize {
100 self.info().dimensions()
101 }
102
103 pub fn color_type(&self) -> ColorType {
104 self.info().color_type()
105 }
106
107 pub fn alpha_type(&self) -> AlphaType {
108 self.info().alpha_type()
109 }
110
111 pub fn color_space(&self) -> Option<ColorSpace> {
112 ColorSpace::from_unshared_ptr(unsafe { self.native().colorSpace() })
113 }
114
115 pub fn is_opaque(&self) -> bool {
116 self.alpha_type().is_opaque()
117 }
118
119 pub fn bounds(&self) -> IRect {
120 IRect::from_wh(self.width(), self.height())
121 }
122
123 pub fn row_bytes_as_pixels(&self) -> usize {
124 self.row_bytes() >> self.shift_per_pixel()
125 }
126
127 pub fn shift_per_pixel(&self) -> usize {
128 self.info().shift_per_pixel()
129 }
130
131 pub fn compute_byte_size(&self) -> usize {
132 self.info().compute_byte_size(self.row_bytes())
133 }
134
135 pub fn compute_is_opaque(&self) -> bool {
136 unsafe { self.native().computeIsOpaque() }
137 }
138
139 pub fn get_color(&self, p: impl Into<IPoint>) -> Color {
140 let p = p.into();
141 self.assert_pixel_exists(p);
142 Color::from_native_c(unsafe { self.native().getColor(p.x, p.y) })
143 }
144
145 pub fn get_color_4f(&self, p: impl Into<IPoint>) -> Color4f {
146 let p = p.into();
147 self.assert_pixel_exists(p);
148 Color4f::from_native_c(unsafe { self.native().getColor4f(p.x, p.y) })
149 }
150
151 pub fn get_alpha_f(&self, p: impl Into<IPoint>) -> f32 {
152 let p = p.into();
153 self.assert_pixel_exists(p);
154 unsafe { self.native().getAlphaf(p.x, p.y) }
155 }
156
157 // Helper to test if the pixel does exist physically in memory.
158 fn assert_pixel_exists(&self, p: impl Into<IPoint>) {
159 let p = p.into();
160 assert!(!self.addr().is_null());
161 assert!(p.x >= 0 && p.x < self.width());
162 assert!(p.y >= 0 && p.y < self.height());
163 }
164
165 pub fn addr_at(&self, p: impl Into<IPoint>) -> *const c_void {
166 let p = p.into();
167 self.assert_pixel_exists(p);
168 unsafe {
169 (self.addr() as *const raw::c_char).add(self.info().compute_offset(p, self.row_bytes()))
170 as _
171 }
172 }
173
174 // TODO: addr8(), addr16(), addr32(), addr64(), addrF16(),
175 // addr8_at(), addr16_at(), addr32_at(), addr64_at(), addrF16_at()
176
177 pub fn writable_addr(&self) -> *mut c_void {
178 self.addr() as _
179 }
180
181 pub fn writable_addr_at(&self, p: impl Into<IPoint>) -> *mut c_void {
182 self.addr_at(p) as _
183 }
184
185 // TODO: writable_addr8
186 // TODO: writable_addr16
187 // TODO: writable_addr32
188 // TODO: writable_addr64
189 // TODO: writable_addrF16
190
191 pub fn read_pixels<P>(
192 &self,
193 dst_info: &ImageInfo,
194 pixels: &mut [P],
195 dst_row_bytes: usize,
196 src: impl Into<IPoint>,
197 ) -> bool {
198 if !dst_info.valid_pixels(dst_row_bytes, pixels) {
199 return false;
200 }
201
202 let src = src.into();
203
204 unsafe {
205 self.native().readPixels(
206 dst_info.native(),
207 pixels.as_mut_ptr() as _,
208 dst_row_bytes,
209 src.x,
210 src.y,
211 )
212 }
213 }
214
215 /// Access the underlying pixels as a byte array. This is a rust-skia specific function.
216 pub fn bytes(&self) -> Option<&'pixels [u8]> {
217 let addr = self.addr().into_option()?;
218 let len = self.compute_byte_size();
219 Some(unsafe { slice::from_raw_parts(addr as *const u8, len) })
220 }
221
222 pub fn bytes_mut(&mut self) -> Option<&'pixels mut [u8]> {
223 let addr = self.writable_addr().into_option()?;
224 let len = self.compute_byte_size();
225 Some(unsafe { slice::from_raw_parts_mut(addr.as_ptr() as *mut u8, len) })
226 }
227
228 /// Access the underlying pixels. This is a rust-skia specific function.
229 ///
230 /// The `Pixel` type must implement the _unsafe_ trait [`Pixel`] and must return `true` in
231 /// [`Pixel::matches_color_type()`] when matched against the [`ColorType`] of this Pixmap's
232 /// pixels.
233 pub fn pixels<P: Pixel>(&self) -> Option<&'pixels [P]> {
234 let addr = self.addr().into_option()?;
235
236 let info = self.info();
237 let ct = info.color_type();
238 let pixel_size = mem::size_of::<P>();
239
240 if info.bytes_per_pixel() == pixel_size && P::matches_color_type(ct) {
241 let len = self.compute_byte_size() / pixel_size;
242 return Some(unsafe { slice::from_raw_parts(addr as *const P, len) });
243 }
244
245 None
246 }
247
248 pub fn read_pixels_to_pixmap(&self, dst: &mut Pixmap, src: impl Into<IPoint>) -> bool {
249 let Some(dst_bytes) = dst.bytes_mut() else {
250 return false;
251 };
252 self.read_pixels(dst.info(), dst_bytes, dst.row_bytes(), src)
253 }
254
255 pub fn scale_pixels(&self, dst: &mut Pixmap, sampling: impl Into<SamplingOptions>) -> bool {
256 let sampling = sampling.into();
257 unsafe { self.native().scalePixels(dst.native(), sampling.native()) }
258 }
259
260 pub fn erase(&mut self, color: impl Into<Color>, subset: Option<&IRect>) -> bool {
261 let color = color.into().into_native();
262 unsafe {
263 match subset {
264 Some(subset) => self.native().erase(color, subset.native()),
265 None => self.native().erase(color, self.bounds().native()),
266 }
267 }
268 }
269
270 pub fn erase_4f(&mut self, color: impl AsRef<Color4f>, subset: Option<&IRect>) -> bool {
271 let color = color.as_ref();
272 unsafe {
273 self.native()
274 .erase1(color.native(), subset.native_ptr_or_null())
275 }
276 }
277
278 fn from_native_c(pixmap: SkPixmap) -> Self {
279 Self {
280 inner: Handle::from_native_c(pixmap),
281 pd: PhantomData,
282 }
283 }
284
285 #[must_use]
286 pub(crate) fn from_native_ref(n: &SkPixmap) -> &Self {
287 unsafe { transmute_ref(n) }
288 }
289
290 #[must_use]
291 pub(crate) fn from_native_ptr(np: *const SkPixmap) -> *const Self {
292 // Should be safe as long `Pixmap` is represented with repr(Transparent).
293 np as _
294 }
295
296 pub(crate) fn native_mut(&mut self) -> &mut SkPixmap {
297 self.inner.native_mut()
298 }
299
300 pub(crate) fn native(&self) -> &SkPixmap {
301 self.inner.native()
302 }
303}
304
305/// Implement this trait to use a pixel type in [`Handle<Pixmap>::pixels()`].
306///
307/// # Safety
308///
309/// This trait is unsafe because external [`Pixel`] implementations may lie about their
310/// [`ColorType`] or fail to match the alignment of the pixels stored in [`Handle<Pixmap>`].
311pub unsafe trait Pixel: Copy {
312 /// `true` if the type matches the color type's format.
313 fn matches_color_type(ct: ColorType) -> bool;
314}
315
316unsafe impl Pixel for u8 {
317 fn matches_color_type(ct: ColorType) -> bool {
318 matches!(ct, ColorType::Alpha8 | ColorType::Gray8)
319 }
320}
321
322unsafe impl Pixel for [u8; 2] {
323 fn matches_color_type(ct: ColorType) -> bool {
324 matches!(ct, ColorType::R8G8UNorm | ColorType::A16UNorm)
325 }
326}
327
328unsafe impl Pixel for (u8, u8) {
329 fn matches_color_type(ct: ColorType) -> bool {
330 matches!(ct, ColorType::R8G8UNorm | ColorType::A16UNorm)
331 }
332}
333
334unsafe impl Pixel for [u8; 4] {
335 fn matches_color_type(ct: ColorType) -> bool {
336 matches!(
337 ct,
338 ColorType::RGBA8888 | ColorType::RGB888x | ColorType::BGRA8888
339 )
340 }
341}
342
343unsafe impl Pixel for (u8, u8, u8, u8) {
344 fn matches_color_type(ct: ColorType) -> bool {
345 matches!(
346 ct,
347 ColorType::RGBA8888 | ColorType::RGB888x | ColorType::BGRA8888
348 )
349 }
350}
351
352unsafe impl Pixel for [f32; 4] {
353 fn matches_color_type(ct: ColorType) -> bool {
354 matches!(ct, ColorType::RGBAF32)
355 }
356}
357
358unsafe impl Pixel for (f32, f32, f32, f32) {
359 fn matches_color_type(ct: ColorType) -> bool {
360 matches!(ct, ColorType::RGBAF32)
361 }
362}
363
364unsafe impl Pixel for u32 {
365 fn matches_color_type(ct: ColorType) -> bool {
366 ct == ColorType::N32
367 }
368}
369
370unsafe impl Pixel for Color {
371 fn matches_color_type(ct: ColorType) -> bool {
372 ct == ColorType::N32
373 }
374}
375
376unsafe impl Pixel for Color4f {
377 fn matches_color_type(ct: ColorType) -> bool {
378 ct == ColorType::RGBAF32
379 }
380}
381
382#[cfg(test)]
383mod tests {
384 use super::*;
385
386 #[test]
387 fn pixmap_mutably_borrows_pixels() {
388 let mut pixels = [0u8; 2 * 2 * 4];
389 let info = ImageInfo::new(
390 (2, 2),
391 ColorType::RGBA8888,
392 AlphaType::Premul,
393 ColorSpace::new_srgb(),
394 );
395 let mut pixmap = Pixmap::new(&info, &mut pixels, info.min_row_bytes()).unwrap();
396 // this must fail to compile:
397 // let _pixel = pixels[0];
398 // use `.bytes()`, or `bytes_mut()` instead.
399 pixmap.reset();
400 }
401
402 #[test]
403 fn addr_may_return_null_from_a_default_pixmap() {
404 let pixmap = Pixmap::default();
405 assert!(pixmap.addr().is_null());
406 assert!(pixmap.writable_addr().is_null());
407 }
408}
409