feat(render): draw passes

1 files changed, 75 insertions, 0 deletions

diff --git a/stockton-render/src/draw/builders/renderpass.rs b/stockton-render/src/draw/builders/renderpass.rs
new file mode 100644
index 0000000..43f0eb2
--- /dev/null
+++ b/stockton-render/src/draw/builders/renderpass.rs
@@ -0,0 +1,75 @@
+use crate::types::*;
+
+use std::iter::{empty, once};
+
+use anyhow::Result;
+use hal::pass::{Attachment, AttachmentRef, SubpassDesc};
+
+#[derive(Debug, Clone)]
+pub struct RenderpassSpec {
+    pub colors: Vec<Attachment>,
+    pub depth: Option<Attachment>,
+    pub inputs: Vec<Attachment>,
+    pub resolves: Vec<Attachment>,
+    pub preserves: Vec<Attachment>,
+}
+
+impl RenderpassSpec {
+    pub fn build_renderpass(self, device: &mut DeviceT) -> Result<RenderPassT> {
+        let mut next_offset = 0;
+
+        let colors: Vec<AttachmentRef> = self
+            .colors
+            .iter()
+            .enumerate()
+            .map(|(i, a)| (next_offset + i, a.layouts.end))
+            .collect();
+        next_offset = colors.len();
+
+        let depth_stencil = self.depth.as_ref().map(|x| (next_offset, x.layouts.end));
+        if depth_stencil.is_some() {
+            next_offset += 1;
+        }
+
+        let inputs: Vec<AttachmentRef> = self
+            .inputs
+            .iter()
+            .enumerate()
+            .map(|(i, a)| (next_offset + i, a.layouts.end))
+            .collect();
+        next_offset += inputs.len();
+
+        let resolves: Vec<AttachmentRef> = self
+            .resolves
+            .iter()
+            .enumerate()
+            .map(|(i, a)| (next_offset + i, a.layouts.end))
+            .collect();
+        next_offset += resolves.len();
+
+        let preserves: Vec<usize> = self
+            .preserves
+            .iter()
+            .enumerate()
+            .map(|(i, _a)| next_offset + i)
+            .collect();
+
+        let sp_desc = SubpassDesc {
+            colors: colors.as_slice(),
+            depth_stencil: depth_stencil.as_ref(),
+            inputs: inputs.as_slice(),
+            resolves: resolves.as_slice(),
+            preserves: preserves.as_slice(),
+        };
+
+        let all_attachments = self
+            .colors
+            .into_iter()
+            .chain(self.depth.into_iter())
+            .chain(self.inputs.into_iter())
+            .chain(self.resolves.into_iter())
+            .chain(self.preserves.into_iter());
+
+        Ok(unsafe { device.create_render_pass(all_attachments, once(sp_desc), empty())? })
+    }
+}