// This file was generated by gir (https://github.com/gtk-rs/gir)
// from gir-files (https://github.com/gtk-rs/gir-files)
// DO NOT EDIT

use crate::{GLUniformType, Renderer};
use glib::{prelude::*, translate::*};

glib::wrapper! {
    /// A [`GLShader`][crate::GLShader] is a snippet of GLSL that is meant to run in the
    /// fragment shader of the rendering pipeline.
    ///
    /// A fragment shader gets the coordinates being rendered as input and
    /// produces the pixel values for that particular pixel. Additionally,
    /// the shader can declare a set of other input arguments, called
    /// uniforms (as they are uniform over all the calls to your shader in
    /// each instance of use). A shader can also receive up to 4
    /// textures that it can use as input when producing the pixel data.
    ///
    /// [`GLShader`][crate::GLShader] is usually used with gtk_snapshot_push_gl_shader()
    /// to produce a [`GLShaderNode`][crate::GLShaderNode] in the rendering hierarchy,
    /// and then its input textures are constructed by rendering the child
    /// nodes to textures before rendering the shader node itself. (You can
    /// pass texture nodes as children if you want to directly use a texture
    /// as input).
    ///
    /// The actual shader code is GLSL code that gets combined with
    /// some other code into the fragment shader. Since the exact
    /// capabilities of the GPU driver differs between different OpenGL
    /// drivers and hardware, GTK adds some defines that you can use
    /// to ensure your GLSL code runs on as many drivers as it can.
    ///
    /// If the OpenGL driver is GLES, then the shader language version
    /// is set to 100, and GSK_GLES will be defined in the shader.
    ///
    /// Otherwise, if the OpenGL driver does not support the 3.2 core profile,
    /// then the shader will run with language version 110 for GL2 and 130 for GL3,
    /// and GSK_LEGACY will be defined in the shader.
    ///
    /// If the OpenGL driver supports the 3.2 code profile, it will be used,
    /// the shader language version is set to 150, and GSK_GL3 will be defined
    /// in the shader.
    ///
    /// The main function the shader must implement is:
    ///
    /// **⚠️ The following code is in glsl ⚠️**
    ///
    /// ```glsl
    ///  void mainImage(out vec4 fragColor,
    ///                 in vec2 fragCoord,
    ///                 in vec2 resolution,
    ///                 in vec2 uv)
    /// ```
    ///
    /// Where the input @fragCoord is the coordinate of the pixel we're
    /// currently rendering, relative to the boundary rectangle that was
    /// specified in the [`GLShaderNode`][crate::GLShaderNode], and @resolution is the width and
    /// height of that rectangle. This is in the typical GTK coordinate
    /// system with the origin in the top left. @uv contains the u and v
    /// coordinates that can be used to index a texture at the
    /// corresponding point. These coordinates are in the [0..1]x[0..1]
    /// region, with 0, 0 being in the lower left corder (which is typical
    /// for OpenGL).
    ///
    /// The output @fragColor should be a RGBA color (with
    /// premultiplied alpha) that will be used as the output for the
    /// specified pixel location. Note that this output will be
    /// automatically clipped to the clip region of the glshader node.
    ///
    /// In addition to the function arguments the shader can define
    /// up to 4 uniforms for textures which must be called u_textureN
    /// (i.e. u_texture1 to u_texture4) as well as any custom uniforms
    /// you want of types int, uint, bool, float, vec2, vec3 or vec4.
    ///
    /// All textures sources contain premultiplied alpha colors, but if some
    /// there are outer sources of colors there is a gsk_premultiply() helper
    /// to compute premultiplication when needed.
    ///
    /// Note that GTK parses the uniform declarations, so each uniform has to
    /// be on a line by itself with no other code, like so:
    ///
    /// **⚠️ The following code is in glsl ⚠️**
    ///
    /// ```glsl
    /// uniform float u_time;
    /// uniform vec3 u_color;
    /// uniform sampler2D u_texture1;
    /// uniform sampler2D u_texture2;
    /// ```
    ///
    /// GTK uses the "gsk" namespace in the symbols it uses in the
    /// shader, so your code should not use any symbols with the prefix gsk
    /// or GSK. There are some helper functions declared that you can use:
    ///
    /// **⚠️ The following code is in glsl ⚠️**
    ///
    /// ```glsl
    /// vec4 GskTexture(sampler2D sampler, vec2 texCoords);
    /// ```
    ///
    /// This samples a texture (e.g. u_texture1) at the specified
    /// coordinates, and contains some helper ifdefs to ensure that
    /// it works on all OpenGL versions.
    ///
    /// You can compile the shader yourself using [`compile()`][Self::compile()],
    /// otherwise the GSK renderer will do it when it handling the glshader
    /// node. If errors occurs, the returned @error will include the glsl
    /// sources, so you can see what GSK was passing to the compiler. You
    /// can also set GSK_DEBUG=shaders in the environment to see the sources
    /// and other relevant information about all shaders that GSK is handling.
    ///
    /// # An example shader
    ///
    /// **⚠️ The following code is in glsl ⚠️**
    ///
    /// ```glsl
    /// uniform float position;
    /// uniform sampler2D u_texture1;
    /// uniform sampler2D u_texture2;
    ///
    /// void mainImage(out vec4 fragColor,
    ///                in vec2 fragCoord,
    ///                in vec2 resolution,
    ///                in vec2 uv) {
    ///   vec4 source1 = GskTexture(u_texture1, uv);
    ///   vec4 source2 = GskTexture(u_texture2, uv);
    ///
    ///   fragColor = position * source1 + (1.0 - position) * source2;
    /// }
    /// ```
    ///
    /// ## Properties
    ///
    ///
    /// #### `resource`
    ///  Resource containing the source code for the shader.
    ///
    /// If the shader source is not coming from a resource, this
    /// will be [`None`].
    ///
    /// Readable | Writeable | Construct Only
    ///
    ///
    /// #### `source`
    ///  Readable | Writeable | Construct Only
    #[doc(alias = "GskGLShader")]
    pub struct GLShader(Object<ffi::GskGLShader, ffi::GskGLShaderClass>);

    match fn {
        type_ => || ffi::gsk_gl_shader_get_type(),
    }
}

impl GLShader {
    /// Creates a [`GLShader`][crate::GLShader] that will render pixels using the specified code.
    /// ## `sourcecode`
    /// GLSL sourcecode for the shader, as a `GBytes`
    ///
    /// # Returns
    ///
    /// A new [`GLShader`][crate::GLShader]
    #[doc(alias = "gsk_gl_shader_new_from_bytes")]
    #[doc(alias = "new_from_bytes")]
    pub fn from_bytes(sourcecode: &glib::Bytes) -> GLShader {
        assert_initialized_main_thread!();
        unsafe {
            from_glib_full(ffi::gsk_gl_shader_new_from_bytes(
                sourcecode.to_glib_none().0,
            ))
        }
    }

    /// Creates a [`GLShader`][crate::GLShader] that will render pixels using the specified code.
    /// ## `resource_path`
    /// path to a resource that contains the GLSL sourcecode for
    ///     the shader
    ///
    /// # Returns
    ///
    /// A new [`GLShader`][crate::GLShader]
    #[doc(alias = "gsk_gl_shader_new_from_resource")]
    #[doc(alias = "new_from_resource")]
    pub fn from_resource(resource_path: &str) -> GLShader {
        assert_initialized_main_thread!();
        unsafe {
            from_glib_full(ffi::gsk_gl_shader_new_from_resource(
                resource_path.to_glib_none().0,
            ))
        }
    }

    // rustdoc-stripper-ignore-next
    /// Creates a new builder-pattern struct instance to construct [`GLShader`] objects.
    ///
    /// This method returns an instance of [`GLShaderBuilder`](crate::builders::GLShaderBuilder) which can be used to create [`GLShader`] objects.
    pub fn builder() -> GLShaderBuilder {
        GLShaderBuilder::new()
    }

    /// Tries to compile the @self for the given @renderer.
    ///
    /// If there is a problem, this function returns [`false`] and reports
    /// an error. You should use this function before relying on the shader
    /// for rendering and use a fallback with a simpler shader or without
    /// shaders if it fails.
    ///
    /// Note that this will modify the rendering state (for example
    /// change the current GL context) and requires the renderer to be
    /// set up. This means that the widget has to be realized. Commonly you
    /// want to call this from the realize signal of a widget, or during
    /// widget snapshot.
    /// ## `renderer`
    /// a [`Renderer`][crate::Renderer]
    ///
    /// # Returns
    ///
    /// [`true`] on success, [`false`] if an error occurred
    #[doc(alias = "gsk_gl_shader_compile")]
    pub fn compile(&self, renderer: &impl IsA<Renderer>) -> Result<(), glib::Error> {
        unsafe {
            let mut error = std::ptr::null_mut();
            let is_ok = ffi::gsk_gl_shader_compile(
                self.to_glib_none().0,
                renderer.as_ref().to_glib_none().0,
                &mut error,
            );
            debug_assert_eq!(is_ok == glib::ffi::GFALSE, !error.is_null());
            if error.is_null() {
                Ok(())
            } else {
                Err(from_glib_full(error))
            }
        }
    }

    /// Looks for a uniform by the name @name, and returns the index
    /// of the uniform, or -1 if it was not found.
    /// ## `name`
    /// uniform name
    ///
    /// # Returns
    ///
    /// The index of the uniform, or -1
    #[doc(alias = "gsk_gl_shader_find_uniform_by_name")]
    pub fn find_uniform_by_name(&self, name: &str) -> i32 {
        unsafe {
            ffi::gsk_gl_shader_find_uniform_by_name(self.to_glib_none().0, name.to_glib_none().0)
        }
    }

    /// Gets the value of the uniform @idx in the @args block.
    ///
    /// The uniform must be of bool type.
    /// ## `args`
    /// uniform arguments
    /// ## `idx`
    /// index of the uniform
    ///
    /// # Returns
    ///
    /// The value
    #[doc(alias = "gsk_gl_shader_get_arg_bool")]
    #[doc(alias = "get_arg_bool")]
    pub fn arg_bool(&self, args: &glib::Bytes, idx: i32) -> bool {
        unsafe {
            from_glib(ffi::gsk_gl_shader_get_arg_bool(
                self.to_glib_none().0,
                args.to_glib_none().0,
                idx,
            ))
        }
    }

    /// Gets the value of the uniform @idx in the @args block.
    ///
    /// The uniform must be of float type.
    /// ## `args`
    /// uniform arguments
    /// ## `idx`
    /// index of the uniform
    ///
    /// # Returns
    ///
    /// The value
    #[doc(alias = "gsk_gl_shader_get_arg_float")]
    #[doc(alias = "get_arg_float")]
    pub fn arg_float(&self, args: &glib::Bytes, idx: i32) -> f32 {
        unsafe {
            ffi::gsk_gl_shader_get_arg_float(self.to_glib_none().0, args.to_glib_none().0, idx)
        }
    }

    /// Gets the value of the uniform @idx in the @args block.
    ///
    /// The uniform must be of int type.
    /// ## `args`
    /// uniform arguments
    /// ## `idx`
    /// index of the uniform
    ///
    /// # Returns
    ///
    /// The value
    #[doc(alias = "gsk_gl_shader_get_arg_int")]
    #[doc(alias = "get_arg_int")]
    pub fn arg_int(&self, args: &glib::Bytes, idx: i32) -> i32 {
        unsafe { ffi::gsk_gl_shader_get_arg_int(self.to_glib_none().0, args.to_glib_none().0, idx) }
    }

    /// Gets the value of the uniform @idx in the @args block.
    ///
    /// The uniform must be of uint type.
    /// ## `args`
    /// uniform arguments
    /// ## `idx`
    /// index of the uniform
    ///
    /// # Returns
    ///
    /// The value
    #[doc(alias = "gsk_gl_shader_get_arg_uint")]
    #[doc(alias = "get_arg_uint")]
    pub fn arg_uint(&self, args: &glib::Bytes, idx: i32) -> u32 {
        unsafe {
            ffi::gsk_gl_shader_get_arg_uint(self.to_glib_none().0, args.to_glib_none().0, idx)
        }
    }

    /// Get the size of the data block used to specify arguments for this shader.
    ///
    /// # Returns
    ///
    /// The size of the data block
    #[doc(alias = "gsk_gl_shader_get_args_size")]
    #[doc(alias = "get_args_size")]
    pub fn args_size(&self) -> usize {
        unsafe { ffi::gsk_gl_shader_get_args_size(self.to_glib_none().0) }
    }

    /// Returns the number of textures that the shader requires.
    ///
    /// This can be used to check that the a passed shader works
    /// in your usecase. It is determined by looking at the highest
    /// u_textureN value that the shader defines.
    ///
    /// # Returns
    ///
    /// The number of texture inputs required by @self
    #[doc(alias = "gsk_gl_shader_get_n_textures")]
    #[doc(alias = "get_n_textures")]
    pub fn n_textures(&self) -> i32 {
        unsafe { ffi::gsk_gl_shader_get_n_textures(self.to_glib_none().0) }
    }

    /// Get the number of declared uniforms for this shader.
    ///
    /// # Returns
    ///
    /// The number of declared uniforms
    #[doc(alias = "gsk_gl_shader_get_n_uniforms")]
    #[doc(alias = "get_n_uniforms")]
    pub fn n_uniforms(&self) -> i32 {
        unsafe { ffi::gsk_gl_shader_get_n_uniforms(self.to_glib_none().0) }
    }

    /// Gets the resource path for the GLSL sourcecode being used
    /// to render this shader.
    ///
    /// # Returns
    ///
    /// The resource path for the shader
    #[doc(alias = "gsk_gl_shader_get_resource")]
    #[doc(alias = "get_resource")]
    pub fn resource(&self) -> Option<glib::GString> {
        unsafe { from_glib_none(ffi::gsk_gl_shader_get_resource(self.to_glib_none().0)) }
    }

    /// Gets the GLSL sourcecode being used to render this shader.
    ///
    /// # Returns
    ///
    /// The source code for the shader
    #[doc(alias = "gsk_gl_shader_get_source")]
    #[doc(alias = "get_source")]
    pub fn source(&self) -> glib::Bytes {
        unsafe { from_glib_none(ffi::gsk_gl_shader_get_source(self.to_glib_none().0)) }
    }

    /// Get the name of the declared uniform for this shader at index @idx.
    /// ## `idx`
    /// index of the uniform
    ///
    /// # Returns
    ///
    /// The name of the declared uniform
    #[doc(alias = "gsk_gl_shader_get_uniform_name")]
    #[doc(alias = "get_uniform_name")]
    pub fn uniform_name(&self, idx: i32) -> glib::GString {
        unsafe {
            from_glib_none(ffi::gsk_gl_shader_get_uniform_name(
                self.to_glib_none().0,
                idx,
            ))
        }
    }

    /// Get the offset into the data block where data for this uniforms is stored.
    /// ## `idx`
    /// index of the uniform
    ///
    /// # Returns
    ///
    /// The data offset
    #[doc(alias = "gsk_gl_shader_get_uniform_offset")]
    #[doc(alias = "get_uniform_offset")]
    pub fn uniform_offset(&self, idx: i32) -> i32 {
        unsafe { ffi::gsk_gl_shader_get_uniform_offset(self.to_glib_none().0, idx) }
    }

    /// Get the type of the declared uniform for this shader at index @idx.
    /// ## `idx`
    /// index of the uniform
    ///
    /// # Returns
    ///
    /// The type of the declared uniform
    #[doc(alias = "gsk_gl_shader_get_uniform_type")]
    #[doc(alias = "get_uniform_type")]
    pub fn uniform_type(&self, idx: i32) -> GLUniformType {
        unsafe {
            from_glib(ffi::gsk_gl_shader_get_uniform_type(
                self.to_glib_none().0,
                idx,
            ))
        }
    }
}

// rustdoc-stripper-ignore-next
/// A [builder-pattern] type to construct [`GLShader`] objects.
///
/// [builder-pattern]: https://doc.rust-lang.org/1.0.0/style/ownership/builders.html
#[must_use = "The builder must be built to be used"]
pub struct GLShaderBuilder {
    builder: glib::object::ObjectBuilder<'static, GLShader>,
}

impl GLShaderBuilder {
    fn new() -> Self {
        Self {
            builder: glib::object::Object::builder(),
        }
    }

    /// Resource containing the source code for the shader.
    ///
    /// If the shader source is not coming from a resource, this
    /// will be [`None`].
    pub fn resource(self, resource: impl Into<glib::GString>) -> Self {
        Self {
            builder: self.builder.property("resource", resource.into()),
        }
    }

    pub fn source(self, source: &glib::Bytes) -> Self {
        Self {
            builder: self.builder.property("source", source.clone()),
        }
    }

    // rustdoc-stripper-ignore-next
    /// Build the [`GLShader`].
    #[must_use = "Building the object from the builder is usually expensive and is not expected to have side effects"]
    pub fn build(self) -> GLShader {
        self.builder.build()
    }
}