1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213
//! Shader stages, programs and uniforms. //! //! This module contains everything related to _shaders_. Shader programs — shaders, for short — //! are GPU binaries that run to perform a series of transformation. Typically run when a draw //! command is issued, they are responsible for: //! //! - Transforming vertex data. This is done in a _vertex shader_. Vertex data, such as the //! positions, colors, UV coordinates, bi-tangents, etc. of each vertices will go through the //! vertex shader and get transformed based on the code provided inside the stage. For example, //! vertices can be projected on the screen with a perspective and view matrices. //! - Tessellating primitive patches. This is done in _tessellation shaders_. //! - Filtering, transforming again or even generating new vertices and primitives. This is done //! by the _geometry shader_. //! - And finally, outputting a color for each _fragment_ covered by the objects you render. This //! is done by the _fragment shader_. //! //! # Shader stages //! //! Right now, five shader stages — [`Stage`] — are supported, ordered by usage in the graphics //! pipeline: //! //! 1. [`StageType::VertexShader`]. //! 2. [`StageType::TessellationControlShader`]. //! 3. [`StageType::TessellationEvaluationShader`]. //! 4. [`StageType::GeometryShader`]. //! 5. [`StageType::FragmentShader`]. //! //! Those are not all mandatory: only the _vertex_ stage and _fragment_ stages are mandatory. If //! you want tessellation shaders, you have to provide both of them. //! //! Shader stages — [`Stage`] — are compiled independently at runtime by your GPU driver, and then //! _linked_ into a shader program. The creation of a [`Stage`] implies using an input string, //! representing the _source code_ of the stage. This is an opaque [`String`] that must represent //! a GLSL stage. The backend will transform the string into its own representation if needed. //! //! > For this version of the crate, the GLSL string must be at least 330-compliant. It is possible //! > that this changes in the future to be more flexible, but right now GLSL 150, for instance, is //! > not allowed. //! //! # Shader program //! //! A shader program — [`Program`] is akin to a binary program, but runs on GPU. It is invoked when //! you issue draw commands. It will run each stages you’ve put in it to transform vertices and //! rasterize fragments inside a framebuffer. Once this is done, the framebuffer will contain //! altered fragments by the final stage (fragment shader). If the shader program outputs several //! properties, we call that situation _MRT_ (Multiple Render Target) and the framebuffer must be //! configured to be able to receive those outputs — basically, it means that its _color slots_ //! and/or _depth slots_ must adapt to the output of the shader program. //! //! Creating shader programs is done by gathering the [`Stage`] you want and _linking_ them. Some //! helper methods allow to create a shader [`Program`] directly from the string source for each //! stage, removing the need to build each stage individually. //! //! Shader programs are typed with three important piece of information: //! //! - The vertex [`Semantics`]. //! - The render target outputs. //! - The [`UniformInterface`]. //! //! //! # Vertex semantics //! //! When a shader program runs, it first executes the mandatory _vertex stage on a set of //! vertices. Those vertices have a given format — that is described by the [`Vertex`] trait. //! Because running a shader on an incompatible vertex would yield wrong results, both the //! vertices and the shader program must be tagged with a type which must implement the //! [`Semantics`] trait. More on that on the documentation of [`Semantics`]. //! //! # Render target outputs //! //! A shader program, in its final mandatory _fragment stage_, will write values into the currently //! in-use framebuffer. The number of “channels” to write to represents the render targets. //! Typically, simple renders will simply write the color of a pixel — so only one render target. //! In that case, the type of the output of the shader program must match the color slot of the //! framebuffer it is used with. //! //! However, it is possible to write more data. For instance, //! [deferred shading](https://en.wikipedia.org/wiki/Deferred_shading) is a technique that requires //! to write several data to a framebuffer, called G-buffer (for geometry buffer): space //! coordinates, normals, tangents, bi-tangents, etc. In that case, your framebuffer must have //! a type matching the outputs of the fragment shader, too. //! //! # Shader customization //! //! A shader [`Program`] represents some code, in a binary form, that transform data. If you //! consider such code, it can adapt to the kind of data it receives, but the behavior is static. //! That means that it shouldn’t be possible to ask the program to do something else — shader //! programs don’t have a state as they must be spawned in parallel for your vertices, pixels, etc. //! However, there is a way to dynamically change what happens inside a shader program. That way //! //! The concept is similar to environment variables: you can declare, in your shader stages, //! _environment variables_ that will receive values from the host (i.e. on the Rust side). It is //! not possible to change those values while a draw command is issued: you have to change them //! in between draw commands. For this reason, those environment variables are often called //! _constant buffers_, _uniform_, _uniform buffers_, etc. by several graphics libraries. In our //! case, right now, we call them [`Uniform`]. //! //! ## Uniforms //! //! A [`Uniform`] is parametric type that accepts the type of the value it will be able to change. //! For instance, `Uniform<f32>` represents a `f32` that can be changed in a shader program. That //! value can be set by the Rust program when the shader program is not currently in use — no //! draw commands. //! //! A [`Uniform`] is a _single_ variable that allows the most basic form of customization. It’s //! very similar to environment variables. You can declare several ones as you would declare //! several environment variables. More on that on the documentation of [`Uniform`]. //! //! ## Uniform buffers //! //! > This section is under heavy rewriting, both the documentation and API. //! //! Sometimes, you will want to set and pass around rich and more complex data. Instead of a `f32`, //! you will want to pass a `struct`. This operation is currently supported but highly unsafe. The //! reason for this is that your GPU will expect a specific kind of memory layout for the types //! you use, and that also depends on the backend you use. //! //! Also, passing a lot of data is not very practical with default [`Uniform`] directly. //! //! In order to pass more data or `struct`s, you need to create a [`Buffer`]. That buffer will //! simply contain the data / object(s) you want to pass to the shader. It is then possible, via //! the use of a [`Pipeline`], to retrieve a [`BoundBuffer`], which can be used to get a //! [`BufferBinding`]. That [`BufferBinding`] can then be set on a //! `Uniform<BufferBinding<YourType>>`, telling your shader program where to grab the data — from //! the bound buffer. //! //! This way of doing is very practical and powerful but currently, in this version of the crate, //! very unsafe. A better API will be available in a next release to make all this simpler and //! safer. //! //! ## Uniform interfaces //! //! As with vertex semantics and render targets, the uniforms that can be used with a shader program //! are part of its type, too, and represented by a single type that must implement //! [`UniformInterface`]. That type can contain anything, but it is advised to just put [`Uniform`] //! fields in it. More on the [`UniformInterface`] documentation. //! //! [`Vertex`]: crate::vertex::Vertex //! [`Buffer`]: crate::buffer::Buffer //! [`Pipeline`]: crate::pipeline::Pipeline //! [`BoundBuffer`]: crate::pipeline::BoundBuffer //! [`BufferBinding`]: crate::pipeline::BufferBinding use std::error; use std::fmt; use std::marker::PhantomData; use crate::backend::shader::{Shader, Uniformable}; use crate::context::GraphicsContext; use crate::vertex::Semantics; /// A shader stage type. #[derive(Clone, Copy, Debug, Eq, PartialEq)] pub enum StageType { /// Vertex shader. VertexShader, /// Tessellation control shader. TessellationControlShader, /// Tessellation evaluation shader. TessellationEvaluationShader, /// Geometry shader. GeometryShader, /// Fragment shader. FragmentShader, } impl fmt::Display for StageType { fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { match *self { StageType::VertexShader => f.write_str("vertex shader"), StageType::TessellationControlShader => f.write_str("tessellation control shader"), StageType::TessellationEvaluationShader => f.write_str("tessellation evaluation shader"), StageType::GeometryShader => f.write_str("geometry shader"), StageType::FragmentShader => f.write_str("fragment shader"), } } } /// Errors that shader stages can emit. #[non_exhaustive] #[derive(Clone, Debug)] pub enum StageError { /// Occurs when a shader fails to compile. CompilationFailed(StageType, String), /// Occurs when you try to create a shader which type is not supported on the current hardware. UnsupportedType(StageType), } impl StageError { /// Occurs when a shader fails to compile. pub fn compilation_failed(ty: StageType, reason: impl Into<String>) -> Self { StageError::CompilationFailed(ty, reason.into()) } /// Occurs when you try to create a shader which type is not supported on the current hardware. pub fn unsupported_type(ty: StageType) -> Self { StageError::UnsupportedType(ty) } } impl fmt::Display for StageError { fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { match *self { StageError::CompilationFailed(ref ty, ref r) => write!(f, "{} compilation error: {}", ty, r), StageError::UnsupportedType(ty) => write!(f, "unsupported {}", ty), } } } impl error::Error for StageError {} impl From<StageError> for ProgramError { fn from(e: StageError) -> Self { ProgramError::StageError(e) } } /// Tessellation stages. /// /// - The `control` stage represents the _tessellation control stage_, which is invoked first. /// - The `evaluation` stage represents the _tessellation evaluation stage_, which is invoked after /// the control stage has finished. /// /// # Parametricity /// /// - `S` is the representation of the stage. Depending on the interface you choose to create a /// [`Program`], it might be a [`Stage`] or something akin to [`&str`] / [`String`]. /// /// [`&str`]: str pub struct TessellationStages<'a, S> where S: ?Sized, { /// Tessellation control representation. pub control: &'a S, /// Tessellation evaluation representation. pub evaluation: &'a S, } /// Errors that a [`Program`] can generate. #[non_exhaustive] #[derive(Debug)] pub enum ProgramError { /// Creating the program failed. CreationFailed(String), /// A shader stage failed to compile or validate its state. StageError(StageError), /// Program link failed. You can inspect the reason by looking at the contained [`String`]. LinkFailed(String), /// A program warning. Warning(ProgramWarning), } impl ProgramError { /// Creating the program failed. pub fn creation_failed(reason: impl Into<String>) -> Self { ProgramError::CreationFailed(reason.into()) } /// A shader stage failed to compile or validate its state. pub fn stage_error(e: StageError) -> Self { ProgramError::StageError(e) } /// Program link failed. You can inspect the reason by looking at the contained [`String`]. pub fn link_failed(reason: impl Into<String>) -> Self { ProgramError::LinkFailed(reason.into()) } /// A program warning. pub fn warning(w: ProgramWarning) -> Self { ProgramError::Warning(w) } } impl fmt::Display for ProgramError { fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { match *self { ProgramError::CreationFailed(ref e) => write!(f, "cannot create shader program: {}", e), ProgramError::StageError(ref e) => write!(f, "shader program has stage error: {}", e), ProgramError::LinkFailed(ref s) => write!(f, "shader program failed to link: {}", s), ProgramError::Warning(ref e) => write!(f, "shader program warning: {}", e), } } } impl error::Error for ProgramError { fn source(&self) -> Option<&(dyn error::Error + 'static)> { match self { ProgramError::StageError(e) => Some(e), _ => None, } } } /// Program warnings, not necessarily considered blocking errors. #[derive(Debug)] pub enum ProgramWarning { /// Some uniform configuration is ill-formed. It can be a problem of inactive uniform, mismatch /// type, etc. Check the [`UniformWarning`] type for more information. Uniform(UniformWarning), /// Some vertex attribute is ill-formed. VertexAttrib(VertexAttribWarning), } impl fmt::Display for ProgramWarning { fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { match *self { ProgramWarning::Uniform(ref e) => write!(f, "uniform warning: {}", e), ProgramWarning::VertexAttrib(ref e) => write!(f, "vertex attribute warning: {}", e), } } } impl error::Error for ProgramWarning { fn source(&self) -> Option<&(dyn error::Error + 'static)> { match self { ProgramWarning::Uniform(e) => Some(e), ProgramWarning::VertexAttrib(e) => Some(e), } } } impl From<ProgramWarning> for ProgramError { fn from(e: ProgramWarning) -> Self { ProgramError::Warning(e) } } /// Warnings related to uniform issues. #[non_exhaustive] #[derive(Debug)] pub enum UniformWarning { /// Inactive uniform (not in use / no participation to the final output in shaders). Inactive(String), /// Type mismatch between the static requested type (i.e. the `T` in [`Uniform<T>`] for instance) /// and the type that got reflected from the backend in the shaders. /// /// The [`String`] is the name of the uniform; the second one gives the type mismatch. /// /// [`Uniform<T>`]: crate::shader::Uniform TypeMismatch(String, UniformType), /// The requested type is unsupported by the backend. /// /// The [`String`] is the name of the uniform. The [`UniformType`] is the type that is not /// supported by the backend. UnsupportedType(String, UniformType), } impl UniformWarning { /// Create an inactive uniform warning. pub fn inactive<N>(name: N) -> Self where N: Into<String>, { UniformWarning::Inactive(name.into()) } /// Create a type mismatch. pub fn type_mismatch<N>(name: N, ty: UniformType) -> Self where N: Into<String>, { UniformWarning::TypeMismatch(name.into(), ty) } /// Create an unsupported type error. pub fn unsupported_type<N>(name: N, ty: UniformType) -> Self where N: Into<String>, { UniformWarning::UnsupportedType(name.into(), ty) } } impl fmt::Display for UniformWarning { fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { match *self { UniformWarning::Inactive(ref s) => write!(f, "inactive {} uniform", s), UniformWarning::TypeMismatch(ref n, ref t) => { write!(f, "type mismatch for uniform {}: {}", n, t) } UniformWarning::UnsupportedType(ref name, ref ty) => { write!(f, "unsupported type {} for uniform {}", ty, name) } } } } impl From<UniformWarning> for ProgramWarning { fn from(e: UniformWarning) -> Self { ProgramWarning::Uniform(e) } } impl error::Error for UniformWarning {} /// Warnings related to vertex attributes issues. #[non_exhaustive] #[derive(Debug)] pub enum VertexAttribWarning { /// Inactive vertex attribute (not read). Inactive(String), } impl VertexAttribWarning { /// Inactive vertex attribute (not read). pub fn inactive(attrib: impl Into<String>) -> Self { VertexAttribWarning::Inactive(attrib.into()) } } impl fmt::Display for VertexAttribWarning { fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { match *self { VertexAttribWarning::Inactive(ref s) => write!(f, "inactive {} vertex attribute", s), } } } impl From<VertexAttribWarning> for ProgramWarning { fn from(e: VertexAttribWarning) -> Self { ProgramWarning::VertexAttrib(e) } } impl error::Error for VertexAttribWarning {} /// A GPU shader program environment variable. /// /// A uniform is a special variable that can be used to send data to a GPU. Several /// forms exist, but the idea is that `T` represents the data you want to send. Some exceptions /// exist that allow to pass _indirect_ data — such as [`BufferBinding`] to pass a buffer, or /// [`TextureBinding`] to pass a texture in order to fetch from it in a shader stage. /// /// You will never be able to store them by your own. Instead, you must use a [`UniformInterface`], /// which provides a _contravariant_ interface for you. Creation is `unsafe` and should be /// avoided. The [`UniformInterface`] is the only safe way to create those. /// /// # Parametricity /// /// - `T` is the type of data you want to be able to set in a shader program. /// /// [`BufferBinding`]: crate::pipeline::BufferBinding /// [`TextureBinding`]: crate::pipeline::TextureBinding #[derive(Debug)] pub struct Uniform<T> where T: ?Sized, { index: i32, _t: PhantomData<*const T>, } impl<T> Uniform<T> where T: ?Sized, { /// Create a new [`Uniform`]. /// /// # Safety /// /// This method must be used **only** by backends. If you end up using it, /// then you’re doing something wrong. Read on [`UniformInterface`] for further /// information. pub unsafe fn new(index: i32) -> Self { Uniform { index, _t: PhantomData, } } /// Retrieve the internal index. /// /// Even though that function is safe, you have no reason to use it. Read on /// [`UniformInterface`] for further details. pub fn index(&self) -> i32 { self.index } } /// Type of a uniform. /// /// This is an exhaustive list of possible types of value you can send to a shader program. /// A [`UniformType`] is associated to any type that can be considered sent via the /// [`Uniformable`] trait. #[derive(Clone, Copy, Debug, Eq, PartialEq)] pub enum UniformType { // scalars /// 32-bit signed integer. Int, /// 32-bit unsigned integer. UInt, /// 32-bit floating-point number. Float, /// 64-bit floating-point number. Double, /// Boolean. Bool, // vectors /// 2D signed integral vector. IVec2, /// 3D signed integral vector. IVec3, /// 4D signed integral vector. IVec4, /// 2D unsigned integral vector. UIVec2, /// 3D unsigned integral vector. UIVec3, /// 4D unsigned integral vector. UIVec4, /// 2D floating-point vector. Vec2, /// 3D floating-point vector. Vec3, /// 4D floating-point vector. Vec4, /// 2D floating-point (double) vector. DVec2, /// 3D floating-point (double) vector. DVec3, /// 4D floating-point (double) vector. DVec4, /// 2D boolean vector. BVec2, /// 3D boolean vector. BVec3, /// 4D boolean vector. BVec4, // matrices /// 2×2 floating-point matrix. M22, /// 3×3 floating-point matrix. M33, /// 4×4 floating-point matrix. M44, /// 2×2 floating-point (double) matrix. DM22, /// 3×3 floating-point (double) matrix. DM33, /// 4×4 floating-point (double) matrix. DM44, // textures /// Signed integral 1D texture sampler. ISampler1D, /// Signed integral 2D texture sampler. ISampler2D, /// Signed integral 3D texture sampler. ISampler3D, /// Signed integral 1D array texture sampler. ISampler1DArray, /// Signed integral 2D array texture sampler. ISampler2DArray, /// Unsigned integral 1D texture sampler. UISampler1D, /// Unsigned integral 2D texture sampler. UISampler2D, /// Unsigned integral 3D texture sampler. UISampler3D, /// Unsigned integral 1D array texture sampler. UISampler1DArray, /// Unsigned integral 2D array texture sampler. UISampler2DArray, /// Floating-point 1D texture sampler. Sampler1D, /// Floating-point 2D texture sampler. Sampler2D, /// Floating-point 3D texture sampler. Sampler3D, /// Floating-point 1D array texture sampler. Sampler1DArray, /// Floating-point 2D array texture sampler. Sampler2DArray, /// Signed cubemap sampler. ICubemap, /// Unsigned cubemap sampler. UICubemap, /// Floating-point cubemap sampler. Cubemap, // buffer /// Buffer binding; used for UBOs. BufferBinding, } impl fmt::Display for UniformType { fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> { match *self { UniformType::Int => f.write_str("int"), UniformType::UInt => f.write_str("uint"), UniformType::Float => f.write_str("float"), UniformType::Double => f.write_str("double"), UniformType::Bool => f.write_str("bool"), UniformType::IVec2 => f.write_str("ivec2"), UniformType::IVec3 => f.write_str("ivec3"), UniformType::IVec4 => f.write_str("ivec4"), UniformType::UIVec2 => f.write_str("uvec2"), UniformType::UIVec3 => f.write_str("uvec3"), UniformType::UIVec4 => f.write_str("uvec4"), UniformType::Vec2 => f.write_str("vec2"), UniformType::Vec3 => f.write_str("vec3"), UniformType::Vec4 => f.write_str("vec4"), UniformType::DVec2 => f.write_str("dvec2"), UniformType::DVec3 => f.write_str("dvec3"), UniformType::DVec4 => f.write_str("dvec4"), UniformType::BVec2 => f.write_str("bvec2"), UniformType::BVec3 => f.write_str("bvec3"), UniformType::BVec4 => f.write_str("bvec4"), UniformType::M22 => f.write_str("mat2"), UniformType::M33 => f.write_str("mat3"), UniformType::M44 => f.write_str("mat4"), UniformType::DM22 => f.write_str("dmat2"), UniformType::DM33 => f.write_str("dmat3"), UniformType::DM44 => f.write_str("dmat4"), UniformType::ISampler1D => f.write_str("isampler1D"), UniformType::ISampler2D => f.write_str("isampler2D"), UniformType::ISampler3D => f.write_str("isampler3D"), UniformType::ISampler1DArray => f.write_str("isampler1DArray"), UniformType::ISampler2DArray => f.write_str("isampler2DArray"), UniformType::UISampler1D => f.write_str("usampler1D"), UniformType::UISampler2D => f.write_str("usampler2D"), UniformType::UISampler3D => f.write_str("usampler3D"), UniformType::UISampler1DArray => f.write_str("usampler1DArray"), UniformType::UISampler2DArray => f.write_str("usampler2DArray"), UniformType::Sampler1D => f.write_str("sampler1D"), UniformType::Sampler2D => f.write_str("sampler2D"), UniformType::Sampler3D => f.write_str("sampler3D"), UniformType::Sampler1DArray => f.write_str("sampler1DArray"), UniformType::Sampler2DArray => f.write_str("sampler2DArray"), UniformType::ICubemap => f.write_str("isamplerCube"), UniformType::UICubemap => f.write_str("usamplerCube"), UniformType::Cubemap => f.write_str("samplerCube"), UniformType::BufferBinding => f.write_str("buffer binding"), } } } /// A shader stage. /// /// # Parametricity /// /// - `B` is the backend type. /// /// [`&str`]: str pub struct Stage<B> where B: ?Sized + Shader, { repr: B::StageRepr, } impl<B> Stage<B> where B: ?Sized + Shader, { /// Create a new stage of type `ty` by compiling `src`. /// /// # Parametricity /// /// - `C` is the graphics context. `C::Backend` must implement the [`Shader`] trait. /// - `R` is the source code to use in the stage. It must implement [`AsRef<str>`]. /// /// # Notes /// /// Feel free to consider using [`GraphicsContext::new_shader_stage`] for a simpler form of /// this method. /// /// [`AsRef<str>`]: AsRef pub fn new<C, R>(ctx: &mut C, ty: StageType, src: R) -> Result<Self, StageError> where C: GraphicsContext<Backend = B>, R: AsRef<str>, { unsafe { ctx .backend() .new_stage(ty, src.as_ref()) .map(|repr| Stage { repr }) } } } /// A builder of [`Uniform`]. /// /// A [`UniformBuilder`] is an important type as it’s the only one that allows to safely create /// [`Uniform`] values. /// /// # Parametricity /// /// - `B` is the backend type. It must implement the [`Shader`] trait. pub struct UniformBuilder<'a, B> where B: ?Sized + Shader, { repr: B::UniformBuilderRepr, warnings: Vec<UniformWarning>, _a: PhantomData<&'a mut ()>, } impl<'a, B> UniformBuilder<'a, B> where B: ?Sized + Shader, { /// Ask the creation of a [`Uniform`], identified by its `name`. pub fn ask<T, N>(&mut self, name: N) -> Result<Uniform<T>, UniformWarning> where N: AsRef<str>, T: Uniformable<B>, { unsafe { B::ask_uniform(&mut self.repr, name.as_ref()) } } /// Ask the creation of a [`Uniform`], identified by its `name`. /// /// If the name is not found, an _unbound_ [`Uniform`] is returned (i.e. a [`Uniform`]) that does /// nothing. pub fn ask_or_unbound<T, N>(&mut self, name: N) -> Uniform<T> where N: AsRef<str>, T: Uniformable<B>, { match self.ask(name) { Ok(uniform) => uniform, Err(err) => { self.warnings.push(err); unsafe { B::unbound(&mut self.repr) } } } } } /// [`Uniform`] interface. /// /// When a type implements [`UniformInterface`], it means that it can be used as part of a shader /// [`Program`] type. When a [`Program`] is in use in a graphics pipeline, its [`UniformInterface`] /// is automatically provided to the user, giving them access to all the fields declared in. Then, /// they can pass data to shaders before issuing draw commands. /// /// # Parametricity /// /// - `B` is the backend type. It must implement [`Shader`]. /// - `E` is the environment type. Set by default to `()`, it allows to pass a mutable /// object at construction-site of the [`UniformInterface`]. It can be useful to generate /// events or customize the way the [`Uniform`] are built by doing some lookups in hashmaps, etc. /// /// # Notes /// /// Implementing this trait — especially [`UniformInterface::uniform_interface`] can be a bit /// overwhelming. It is highly recommended to use [luminance-derive]’s `UniformInterface` /// proc-macro, which will do that for you by scanning your type declaration. /// /// [luminance-derive]: https://crates.io/crates/luminance-derive pub trait UniformInterface<B, E = ()>: Sized where B: ?Sized + Shader, { /// Create a [`UniformInterface`] by constructing [`Uniform`]s with a [`UniformBuilder`] and an /// optional environment object. /// /// This method is the only place where `Self` should be created. In theory, you could create it /// the way you want (since the type is provided by you) but not all types make sense. You will /// likely want to have some [`Uniform`] objects in your type, and the [`UniformBuilder`] that is /// provided as argument is the only way to create them. fn uniform_interface<'a>( builder: &mut UniformBuilder<'a, B>, env: &mut E, ) -> Result<Self, UniformWarning>; } impl<B, E> UniformInterface<B, E> for () where B: ?Sized + Shader, { fn uniform_interface<'a>( _: &mut UniformBuilder<'a, B>, _: &mut E, ) -> Result<Self, UniformWarning> { Ok(()) } } /// A built program with potential warnings. /// /// The sole purpose of this type is to be destructured when a program is built. /// /// # Parametricity /// /// - `B` is the backend type. /// - `Sem` is the [`Semantics`] type. /// - `Out` is the render target type. /// - `Uni` is the [`UniformInterface`] type. pub struct BuiltProgram<B, Sem, Out, Uni> where B: ?Sized + Shader, { /// Built program. pub program: Program<B, Sem, Out, Uni>, /// Potential warnings. pub warnings: Vec<ProgramError>, } impl<B, Sem, Out, Uni> BuiltProgram<B, Sem, Out, Uni> where B: ?Sized + Shader, { /// Get the program and ignore the warnings. pub fn ignore_warnings(self) -> Program<B, Sem, Out, Uni> { self.program } } /// A [`Program`] uniform adaptation that has failed. /// /// # Parametricity /// /// - `B` is the backend type. /// - `Sem` is the [`Semantics`] type. /// - `Out` is the render target type. /// - `Uni` is the [`UniformInterface`] type. pub struct AdaptationFailure<B, Sem, Out, Uni> where B: ?Sized + Shader, { /// Program used before trying to adapt. pub program: Program<B, Sem, Out, Uni>, /// Program error that prevented to adapt. pub error: ProgramError, } impl<B, Sem, Out, Uni> AdaptationFailure<B, Sem, Out, Uni> where B: ?Sized + Shader, { pub(crate) fn new(program: Program<B, Sem, Out, Uni>, error: ProgramError) -> Self { AdaptationFailure { program, error } } /// Get the program and ignore the error. pub fn ignore_error(self) -> Program<B, Sem, Out, Uni> { self.program } } /// Interact with the [`UniformInterface`] carried by a [`Program`] and/or perform dynamic /// uniform lookup. /// /// This type allows to set — [`ProgramInterface::set`] – uniforms for a [`Program`]. /// /// In the case where you don’t have a uniform interface or need to dynamically lookup uniforms, /// you can use the [`ProgramInterface::query`] method. /// /// # Parametricity /// /// `B` is the backend type. pub struct ProgramInterface<'a, B> where B: ?Sized + Shader, { pub(crate) program: &'a mut B::ProgramRepr, } impl<'a, B> ProgramInterface<'a, B> where B: ?Sized + Shader, { /// Set a value on a [`Uniform`]. pub fn set<T>(&mut self, uniform: &Uniform<T>, value: T) where T: Uniformable<B>, { unsafe { T::update(value, self.program, uniform) }; } /// Get back a [`UniformBuilder`] to dynamically access [`Uniform`] objects. pub fn query(&mut self) -> Result<UniformBuilder<'a, B>, ProgramError> { unsafe { B::new_uniform_builder(&mut self.program).map(|repr| UniformBuilder { repr, warnings: Vec::new(), _a: PhantomData, }) } } } /// A [`Program`] builder. /// /// This type allows to create shader programs without having to worry too much about the highly /// generic API. pub struct ProgramBuilder<'a, C, Sem, Out, Uni> { ctx: &'a mut C, _phantom: PhantomData<(Sem, Out, Uni)>, } impl<'a, C, Sem, Out, Uni> ProgramBuilder<'a, C, Sem, Out, Uni> where C: GraphicsContext, C::Backend: Shader, Sem: Semantics, { /// Create a new [`ProgramBuilder`] from a [`GraphicsContext`]. pub fn new(ctx: &'a mut C) -> Self { ProgramBuilder { ctx, _phantom: PhantomData, } } /// Create a [`Program`] by linking [`Stage`]s and accessing a mutable environment variable. /// /// # Parametricity /// /// - `T` is an [`Option`] containing a [`TessellationStages`] with [`Stage`] inside. /// - `G` is an [`Option`] containing a [`Stage`] inside (geometry shader). /// - `E` is the mutable environment variable. /// /// # Notes /// /// Feel free to look at the documentation of [`GraphicsContext::new_shader_program`] for /// a simpler interface. pub fn from_stages_env<'b, T, G, E>( &mut self, vertex: &'b Stage<C::Backend>, tess: T, geometry: G, fragment: &'b Stage<C::Backend>, env: &mut E, ) -> Result<BuiltProgram<C::Backend, Sem, Out, Uni>, ProgramError> where Uni: UniformInterface<C::Backend, E>, T: Into<Option<TessellationStages<'b, Stage<C::Backend>>>>, G: Into<Option<&'b Stage<C::Backend>>>, { let tess = tess.into(); let geometry = geometry.into(); unsafe { let mut repr = self.ctx.backend().new_program( &vertex.repr, tess.map(|stages| TessellationStages { control: &stages.control.repr, evaluation: &stages.evaluation.repr, }), geometry.map(|stage| &stage.repr), &fragment.repr, )?; let warnings = C::Backend::apply_semantics::<Sem>(&mut repr)? .into_iter() .map(|w| ProgramError::Warning(w.into())) .collect(); let mut uniform_builder = C::Backend::new_uniform_builder(&mut repr).map(|repr| UniformBuilder { repr, warnings: Vec::new(), _a: PhantomData, })?; let uni = Uni::uniform_interface(&mut uniform_builder, env).map_err(ProgramWarning::Uniform)?; let program = Program { repr, uni, _sem: PhantomData, _out: PhantomData, }; Ok(BuiltProgram { program, warnings }) } } /// Create a [`Program`] by linking [`Stage`]s. /// /// # Parametricity /// /// - `T` is an [`Option`] containing a [`TessellationStages`] with [`Stage`] inside. /// - `G` is an [`Option`] containing a [`Stage`] inside (geometry shader). /// /// # Notes /// /// Feel free to look at the documentation of [`GraphicsContext::new_shader_program`] for /// a simpler interface. pub fn from_stages<'b, T, G>( &mut self, vertex: &'b Stage<C::Backend>, tess: T, geometry: G, fragment: &'b Stage<C::Backend>, ) -> Result<BuiltProgram<C::Backend, Sem, Out, Uni>, ProgramError> where Uni: UniformInterface<C::Backend>, T: Into<Option<TessellationStages<'b, Stage<C::Backend>>>>, G: Into<Option<&'b Stage<C::Backend>>>, { Self::from_stages_env(self, vertex, tess, geometry, fragment, &mut ()) } /// Create a [`Program`] by linking [`&str`]s and accessing a mutable environment variable. /// /// # Parametricity /// /// - `C` is the graphics context. /// - `T` is an [`Option`] containing a [`TessellationStages`] with [`&str`] inside. /// - `G` is an [`Option`] containing a [`Stage`] inside (geometry shader). /// - `E` is the mutable environment variable. /// /// # Notes /// /// Feel free to look at the documentation of [`GraphicsContext::new_shader_program`] for /// a simpler interface. /// /// [`&str`]: str pub fn from_strings_env<'b, T, G, E>( &mut self, vertex: &'b str, tess: T, geometry: G, fragment: &'b str, env: &mut E, ) -> Result<BuiltProgram<C::Backend, Sem, Out, Uni>, ProgramError> where Uni: UniformInterface<C::Backend, E>, T: Into<Option<TessellationStages<'b, str>>>, G: Into<Option<&'b str>>, { let vs_stage = Stage::new(self.ctx, StageType::VertexShader, vertex)?; let tess_stages = match tess.into() { Some(TessellationStages { control, evaluation, }) => { let control_stage = Stage::new(self.ctx, StageType::TessellationControlShader, control)?; let evaluation_stage = Stage::new( self.ctx, StageType::TessellationEvaluationShader, evaluation, )?; Some((control_stage, evaluation_stage)) } None => None, }; let tess_stages = tess_stages .as_ref() .map(|(ref control, ref evaluation)| TessellationStages { control, evaluation, }); let gs_stage = match geometry.into() { Some(geometry) => Some(Stage::new(self.ctx, StageType::GeometryShader, geometry)?), None => None, }; let fs_stage = Stage::new(self.ctx, StageType::FragmentShader, fragment)?; Self::from_stages_env( self, &vs_stage, tess_stages, gs_stage.as_ref(), &fs_stage, env, ) } /// Create a [`Program`] by linking [`&str`]s. /// /// # Parametricity /// /// - `C` is the graphics context. /// - `T` is an [`Option`] containing a [`TessellationStages`] with [`&str`] inside. /// - `G` is an [`Option`] containing a [`Stage`] inside (geometry shader). /// /// # Notes /// /// Feel free to look at the documentation of [`GraphicsContext::new_shader_program`] for /// a simpler interface. /// /// [`&str`]: str pub fn from_strings<'b, T, G>( &mut self, vertex: &'b str, tess: T, geometry: G, fragment: &'b str, ) -> Result<BuiltProgram<C::Backend, Sem, Out, Uni>, ProgramError> where Uni: UniformInterface<C::Backend>, T: Into<Option<TessellationStages<'b, str>>>, G: Into<Option<&'b str>>, { Self::from_strings_env(self, vertex, tess, geometry, fragment, &mut ()) } } /// A shader program. /// /// Shader programs are GPU binaries that execute when a draw command is issued. /// /// # Parametricity /// /// - `B` is the backend type. /// - `Sem` is the [`Semantics`] type. /// - `Out` is the render target type. /// - `Uni` is the [`UniformInterface`] type. pub struct Program<B, Sem, Out, Uni> where B: ?Sized + Shader, { pub(crate) repr: B::ProgramRepr, pub(crate) uni: Uni, _sem: PhantomData<*const Sem>, _out: PhantomData<*const Out>, } impl<B, Sem, Out, Uni> Program<B, Sem, Out, Uni> where B: ?Sized + Shader, Sem: Semantics, { /// Create a new [`UniformInterface`] but keep the [`Program`] around without rebuilding it. /// /// # Parametricity /// /// - `Q` is the new [`UniformInterface`]. pub fn adapt<Q>(self) -> Result<BuiltProgram<B, Sem, Out, Q>, AdaptationFailure<B, Sem, Out, Uni>> where Q: UniformInterface<B>, { self.adapt_env(&mut ()) } /// Create a new [`UniformInterface`] but keep the [`Program`] around without rebuilding it, by /// using a mutable environment variable. /// /// # Parametricity /// /// - `Q` is the new [`UniformInterface`]. /// - `E` is the mutable environment variable. pub fn adapt_env<Q, E>( mut self, env: &mut E, ) -> Result<BuiltProgram<B, Sem, Out, Q>, AdaptationFailure<B, Sem, Out, Uni>> where Q: UniformInterface<B, E>, { // first, try to create the new uniform interface let mut uniform_builder: UniformBuilder<B> = match unsafe { B::new_uniform_builder(&mut self.repr) } { Ok(repr) => UniformBuilder { repr, warnings: Vec::new(), _a: PhantomData, }, Err(e) => return Err(AdaptationFailure::new(self, e)), }; let uni = match Q::uniform_interface(&mut uniform_builder, env) { Ok(uni) => uni, Err(e) => { return Err(AdaptationFailure::new( self, ProgramWarning::Uniform(e).into(), )) } }; let warnings = uniform_builder .warnings .into_iter() .map(|w| ProgramError::Warning(w.into())) .collect(); let program = Program { repr: self.repr, uni, _sem: PhantomData, _out: PhantomData, }; Ok(BuiltProgram { program, warnings }) } /// Re-create the [`UniformInterface`] but keep the [`Program`] around without rebuilding it. /// /// # Parametricity /// /// - `E` is the mutable environment variable. pub fn readapt_env<E>( self, env: &mut E, ) -> Result<BuiltProgram<B, Sem, Out, Uni>, AdaptationFailure<B, Sem, Out, Uni>> where Uni: UniformInterface<B, E>, { self.adapt_env(env) } }