From 11cab091dcece6e5ec7583a2af6580236220bbd3 Mon Sep 17 00:00:00 2001
From: Sasha Koshka <sashakoshka@tebibyte.media>
Date: Sat, 5 Nov 2022 18:08:00 -0400
Subject: [PATCH] Individually clear dirty cells

---
 backends/pixel/pixel.go | 53 +++++++++++++++++++++++++++++++----------
 stone.go                |  2 --
 2 files changed, 40 insertions(+), 15 deletions(-)
 delete mode 100644 stone.go

diff --git a/backends/pixel/pixel.go b/backends/pixel/pixel.go
index 6976f40..9d09c7f 100644
--- a/backends/pixel/pixel.go
+++ b/backends/pixel/pixel.go
@@ -1,19 +1,22 @@
 package pixel
 
+import "fmt"
 import "time"
 import "golang.org/x/image/font"
 import "github.com/faiface/pixel"
+import "github.com/faiface/pixel/imdraw"
 import "github.com/faiface/pixel/pixelgl"
 import "golang.org/x/image/font/basicfont"
 import "git.tebibyte.media/sashakoshka/stone"
 
 type Backend struct {
-	window         *pixelgl.Window
-	boundsDirty    bool
-	previousBounds pixel.Vec
-	fontFace       font.Face
-	application    *stone.Application
-	config         *stone.Config
+	window            *pixelgl.Window
+	boundsDirty       bool
+	previousBounds    pixel.Vec
+	fontFace          font.Face
+	application       *stone.Application
+	config            *stone.Config
+	backgroundStamper *imdraw.IMDraw
 
 	metrics struct {
 		cellWidth  int
@@ -37,6 +40,7 @@ func (backend *Backend) Run (callback func (application *stone.Application)) {
 	}
 	
 	pixelgl.Run (func () {
+		// construct the window, and all that
 		var err error
 		backend.window, err = pixelgl.NewWindow (pixelgl.WindowConfig {
 			Resizable:   true,
@@ -46,6 +50,7 @@ func (backend *Backend) Run (callback func (application *stone.Application)) {
 			Title:       backend.application.Title(),
 			Bounds:      backend.calculateWindowSize(),
 		})
+		backend.backgroundStamper = imdraw.New(nil)
 		backend.Poll()
 		
 		if err != nil { panic(err.Error()) }
@@ -115,6 +120,7 @@ func (backend *Backend) Resized () (resized bool) {
 
 func (backend *Backend) draw () {
 	// didDrawing := false
+	width, height := backend.application.Size()
 
 	if backend.boundsDirty {
 		backend.window.Clear (
@@ -122,28 +128,42 @@ func (backend *Backend) draw () {
 		backend.boundsDirty = false
 		// didDrawing = true
 	} else {
-		// TODO: clear out dirty cells before drawing them (we don't
-		// want to clear them out if we have already just cleared
-		// everything out)
+		// clear out dirty cells before drawing them. this is in an else
+		// block because if the bounds were dirty, we have already
+		// cleared the entire screen.
 
-		
+		backend.backgroundStamper.Clear()
+		backend.backgroundStamper.Color =
+			backend.config.Color(stone.ColorApplication)
+		for x := 0; x < width; x ++ {
+			for y := 0; y < height; y ++ {
+				clean := backend.application.Clean(x, y)
+				if clean { continue }
+
+				backend.backgroundStamper.Push (
+					backend.vectorAtPosition(x, y),
+					backend.vectorAtPosition(x + 1, y + 1))
+				backend.backgroundStamper.Rectangle(1)
+				// didDrawing = true
+			}
+		}
+		backend.backgroundStamper.Draw(backend.window)
 	}
 
 	// TODO: draw dirty cells.
-	width, height := backend.application.Size()
 	for x := 0; x < width; x ++ {
 		for y := 0; y < height; y ++ {
 			clean := backend.application.Clean(x, y)
 			// cell  := application.content[index]
 			if clean { continue }
+			backend.application.MarkClean(x, y)
 
 			// draw cell
 			cell := backend.application.Cell(x, y)
 			content := cell.Rune()
 			if content < 32 { continue }
+			fmt.Println(content)
 			
-			// didDrawing = true // TODO: set didDrawing up there ^
-			backend.application.MarkClean(x, y)
 		}
 	}
 
@@ -160,6 +180,13 @@ func (backend *Backend) processEvents () {
 	}
 }
 
+func (backend *Backend) vectorAtPosition (x, y int) (vector pixel.Vec) {
+	vector = pixel.V (
+		float64(x * backend.metrics.cellWidth),
+		float64(y * backend.metrics.cellHeight))
+	return
+}
+
 func (backend *Backend) calculateWindowSize () (bounds pixel.Rect) {
 	width, height := backend.application.Size()
 	bounds = pixel.R (
diff --git a/stone.go b/stone.go
deleted file mode 100644
index 7fa45eb..0000000
--- a/stone.go
+++ /dev/null
@@ -1,2 +0,0 @@
-package stone
-