get HDR working

src/graphics.rs

@@ -297,13 +297,19 @@ impl Error for ShaderError {
     }
 }
 
+#[derive(Clone, PartialEq, Debug, Eq, Copy, Hash)]
+/// A marker to prevent the creation of texture formats that aren't always safe to use in safe code without checks
+pub struct PrivateConstruct(());
+
 /// List of all the possible formats of input data when uploading to texture.
 /// The list is built by intersection of texture formats supported by 3.3 core profile and webgl1.
 #[repr(u8)]
 #[derive(Debug, PartialEq, Eq, Clone, Copy, Hash)]
 pub enum TextureFormat {
     RGB8,
     RGBA8,
+    /// Not every openGL version supported by Macroquad supports this texture format.
+    RGBA16(PrivateConstruct),
     Depth,
     Alpha,
 }
@@ -314,10 +320,27 @@ impl TextureFormat {
         match self {
             TextureFormat::RGB8 => 3 * square,
             TextureFormat::RGBA8 => 4 * square,
+            TextureFormat::RGBA16(_) => 4 * square,
             TextureFormat::Depth => 2 * square,
             TextureFormat::Alpha => 1 * square,
         }
     }
+    /// SAFETY:
+    /// Using this method on openGL versions that does not support RGBA16 textures can cause
+    /// UB
+    ///
+    /// Make sure to check first before creating (render) textures with this format
+    pub unsafe fn rgba16_unchecked() -> Self {
+        Self::RGBA16(PrivateConstruct(()))
+    }
+    pub fn rgba16(context: &dyn RenderingBackend) -> Option<Self> {
+        if (!context.is_metal()) && !context.is_opengl3() {
+            return None;
+        }
+        ///SAFETY: We checked before if the rendering backend supports rgba16 textures
+        let format = unsafe { Self::rgba16_unchecked() };
+        Some(format)
+    }
 }
 
 /// Sets the wrap parameter for texture.
@@ -1143,4 +1166,7 @@ pub trait RenderingBackend {
     /// NOTE: num_instances > 1 might be not supported by the GPU (gl2.1 and gles2).
     /// `features.instancing` check is required.
     fn draw(&self, base_element: i32, num_elements: i32, num_instances: i32);
+
+    fn is_opengl3(&self) -> bool;
+    fn is_metal(&self) -> bool;
 }

src/graphics/gl.rs

@@ -57,6 +57,7 @@ impl From<TextureFormat> for (GLenum, GLenum, GLenum) {
         match format {
             TextureFormat::RGB8 => (GL_RGB, GL_RGB, GL_UNSIGNED_BYTE),
             TextureFormat::RGBA8 => (GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE),
+            TextureFormat::RGBA16(_) => (GL_RGBA16F, GL_RGBA, GL_UNSIGNED_BYTE),
             TextureFormat::Depth => (GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT, GL_UNSIGNED_SHORT),
             #[cfg(target_arch = "wasm32")]
             TextureFormat::Alpha => (GL_ALPHA, GL_ALPHA, GL_UNSIGNED_BYTE),
@@ -1331,4 +1332,15 @@ impl RenderingBackend for GlContext {
             );
         }
     }
+
+    fn is_opengl3(&self) -> bool {
+        ///SAFETY:
+        /// the creation of this context already calls is_gl2
+        /// So, presumably calling it here is fine as well?
+        !unsafe { is_gl2() }
+    }
+
+    fn is_metal(&self) -> bool {
+        false
+    }
 }

src/graphics/metal.rs

@@ -1116,4 +1116,10 @@ impl RenderingBackend for MetalContext {
             self.current_frame_index = 0;
         }
     }
+    fn is_metal(&self) -> bool {
+        true
+    }
+    fn is_opengl3(&self) -> bool {
+        false
+    }
 }