2 files changed, 181 insertions, 0 deletions
diff --git a/opengl-bindings/src/blending.rs b/opengl-bindings/src/blending.rs
new file mode 100644
index 0000000..5e8c1ef
--- /dev/null
+++ b/opengl-bindings/src/blending.rs
@@ -0,0 +1,180 @@
+use crate::CurrentContextWithFns;
+
+pub fn configure(
+    current_context: &CurrentContextWithFns<'_>,
+    configuration: Configuration,
+)
+{
+    unsafe {
+        current_context.fns().BlendFunc(
+            configuration.source_factor.into_gl(),
+            configuration.destination_factor.into_gl(),
+        );
+
+        current_context
+            .fns()
+            .BlendEquation(configuration.equation.into_gl());
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Configuration
+{
+    source_factor: Factor,
+    destination_factor: Factor,
+    equation: Equation,
+}
+
+impl Configuration
+{
+    pub fn with_source_factor(mut self, source_factor: Factor) -> Self
+    {
+        self.source_factor = source_factor;
+        self
+    }
+
+    pub fn with_destination_factor(mut self, destination_factor: Factor) -> Self
+    {
+        self.destination_factor = destination_factor;
+        self
+    }
+
+    pub fn with_equation(mut self, equation: Equation) -> Self
+    {
+        self.equation = equation;
+        self
+    }
+}
+
+impl Default for Configuration
+{
+    fn default() -> Self
+    {
+        Self {
+            source_factor: Factor::One,
+            destination_factor: Factor::Zero,
+            equation: Equation::default(),
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+#[non_exhaustive]
+pub enum Factor
+{
+    /// Factor will be the RGBA color `(0,0,0,0)`
+    Zero,
+
+    /// Factor will be the RGBA color `(1,1,1,1)`
+    One,
+
+    /// Factor will be the source color
+    SrcColor,
+
+    /// Factor will be the RGBA color `(1,1,1,1) - source color`
+    OneMinusSrcColor,
+
+    /// Factor will be the destination color
+    DstColor,
+
+    /// Factor will be the RGBA color `(1,1,1,1) - destination color`
+    OneMinusDstColor,
+
+    /// Factor will be the alpha component of the source color.
+    SrcAlpha,
+
+    /// Factor will be the RGBA color `(1,1,1,1) - source color alpha`
+    OneMinusSrcAlpha,
+
+    /// Factor will be the alpha component of the destination color.
+    DstAlpha,
+
+    /// Factor will be the RGBA color `(1,1,1,1) - destination color alpha`
+    OneMinusDstAlpha,
+
+    /// Factor will be the constant color
+    ConstantColor,
+
+    /// Factor will be the RGBA color `(1,1,1,1) - constant color`
+    OneMinusConstantColor,
+
+    /// Factor will be the alpha component of the constant color.
+    ConstantAlpha,
+
+    /// Factor will be the RGBA color `(1,1,1,1) - constant color alpha`
+    OneMinusConstantAlpha,
+    // /// (i,i,i,1)
+    // SrcAlphaSaturate,
+    //
+    // /// (Rs1kR,Gs1kG,Bs1kB,As1kA)
+    // Src1Color,
+    //
+    // /// (1,1,1,1)−(Rs1kR,Gs1kG,Bs1kB,As1kA)
+    // OneMinusSrc1Color,
+    //
+    // /// (As1kA,As1kA,As1kA,As1kA)
+    // Src1Alpha,
+    //
+    // /// (1,1,1,1)−(As1kA,As1kA,As1kA,As1kA)
+    // OneMinusSrc1Alpha,
+}
+
+impl Factor
+{
+    fn into_gl(self) -> crate::sys::types::GLenum
+    {
+        match self {
+            Self::Zero => crate::sys::ZERO,
+            Self::One => crate::sys::ONE,
+            Self::SrcColor => crate::sys::SRC_COLOR,
+            Self::OneMinusSrcColor => crate::sys::ONE_MINUS_SRC_COLOR,
+            Self::DstColor => crate::sys::DST_COLOR,
+            Self::OneMinusDstColor => crate::sys::ONE_MINUS_DST_COLOR,
+            Self::SrcAlpha => crate::sys::SRC_ALPHA,
+            Self::OneMinusSrcAlpha => crate::sys::ONE_MINUS_SRC_ALPHA,
+            Self::DstAlpha => crate::sys::DST_ALPHA,
+            Self::OneMinusDstAlpha => crate::sys::ONE_MINUS_DST_ALPHA,
+            Self::ConstantColor => crate::sys::CONSTANT_COLOR,
+            Self::OneMinusConstantColor => crate::sys::ONE_MINUS_CONSTANT_COLOR,
+            Self::ConstantAlpha => crate::sys::CONSTANT_ALPHA,
+            Self::OneMinusConstantAlpha => crate::sys::ONE_MINUS_CONSTANT_ALPHA,
+        }
+    }
+}
+
+#[derive(Debug, Default, Clone, Copy)]
+pub enum Equation
+{
+    /// The destination color and source color is added to each other in the blend
+    /// function
+    #[default]
+    Add,
+
+    /// The destination color is subtracted from the source color in the blend function
+    Subtract,
+
+    /// The source color is subtracted from the destination color in the blend function
+    ReverseSubtract,
+
+    /// The blend function will take the component-wise minimum of the destination color
+    /// and the source color
+    Min,
+
+    /// The blend function will take the component-wise maximum of the destination color
+    /// and the source color
+    Max,
+}
+
+impl Equation
+{
+    fn into_gl(self) -> crate::sys::types::GLenum
+    {
+        match self {
+            Self::Add => crate::sys::FUNC_ADD,
+            Self::Subtract => crate::sys::FUNC_SUBTRACT,
+            Self::ReverseSubtract => crate::sys::FUNC_REVERSE_SUBTRACT,
+            Self::Min => crate::sys::MIN,
+            Self::Max => crate::sys::MAX,
+        }
+    }
+}
diff --git a/opengl-bindings/src/lib.rs b/opengl-bindings/src/lib.rs
index 7fd9933..af80e69 100644
--- a/opengl-bindings/src/lib.rs
+++ b/opengl-bindings/src/lib.rs
@@ -7,6 +7,7 @@ use glutin::display::GetGlDisplay;
 use glutin::prelude::{GlDisplay, NotCurrentGlContext, PossiblyCurrentGlContext};
 use glutin::surface::{Surface, SurfaceTypeTrait};
 
+pub mod blending;
 pub mod buffer;
 pub mod data_types;
 pub mod debug;