yterm

diff --git a/source/app.c b/source/app.c
index 61a9771ed4e29c3c33e456da4f4e80b0389e7843..ed4ce6eed5076ca7154a7c24cb3bd014cc3d918b 100644
--- a/source/app.c
+++ b/source/app.c
@@ -86,7 +86,7 @@
 	Rect within = {0, 1, screen.buffer.width, screen.buffer.height - 1};
 	Pane_Render(&app.tabs[app.tabSel], within);
 
-	Backend_Render();
+	Screen_Render();
 	oldFrameTime = newFrameTime;
 }
 




diff --git a/source/backend.h b/source/backend.h
index cdb23f1a85e28156272be8bc6a92bb95a6bd419b..4dadee10dceace2eaaa7d001f520a7fc7cb60b33 100644
--- a/source/backend.h
+++ b/source/backend.h
@@ -38,8 +38,6 @@ Texture* Backend_LoadTexture(uint8_t* data, int w, int h, int aW, int aH, int ch);
 void     Backend_FreeTexture(Texture* texture);
 Vec2     Backend_GetTextureSize(Texture* texture);
 void     Backend_OnWindowResize(void);
-void     Backend_OnScreenUpdate(void);
-void     Backend_OnCellChange(int x, int y);
 void     Backend_Render(void);
 
 #endif




diff --git a/source/backends/soft.c b/source/backends/soft.c
index 15d93abf719315ee6a9e80623cf70aa0aba6b225..33709c93f12e00e613b13a101abe2c91f93aa7c4 100644
--- a/source/backends/soft.c
+++ b/source/backends/soft.c
@@ -23,7 +23,6 @@ 	BTexture  textures[32];
 	uint32_t* buffer;
 	int       bufferW;
 	int       bufferH;
-	bool*     changes;
 	bool      redraw;
 
 	// SDL stuff
@@ -82,8 +81,7 @@
 	state.buffer  = SafeMalloc(video.windows[0].width * video.windows[0].height * sizeof(uint32_t));
 	state.bufferW = video.windows[0].width;
 	state.bufferH = video.windows[0].height;
-
-	state.changes = NULL;
+	state.redraw  = true;
 }
 
 static void Free(void) {
@@ -137,18 +135,6 @@ static void OnWindowResize(void) {
 	
 }
 
-static void OnScreenUpdate(void) {
-	if (!state.changes) {
-		free(state.changes);
-	}
-
-	size_t size = screen.buffer.width * screen.buffer.height * sizeof(bool);
-	state.changes = SafeMalloc(size);
-	memset(state.changes, 0, size);
-
-	state.redraw = true;
-}
-
 static void FillRect(int x, int y, int w, int h, Colour colour) {
 	for (int iy = 0; iy < h; ++ iy) {
 		for (int ix = 0; ix < w; ++ ix) {
@@ -180,10 +166,6 @@
 			DrawPixel(ix + x, iy + y, srcPix);
 		}
 	}
-}
-
-static void OnCellChange(int x, int y) {
-	state.changes[(y * screen.buffer.width) + x] = true;
 }
 
 static void Render(void) {
@@ -199,9 +181,7 @@ 	Font_CharSize(&screen.font, &cw, &ch);
 
 	for (int y = 0; y < screen.buffer.height; ++ y) {
 		for (int x = 0; x < screen.buffer.width; ++ x) {
-			if (!state.changes[(y * screen.buffer.width) + x] && !state.redraw) continue;
-
-			state.changes[(y * screen.buffer.width) + x] = false;
+			if (!Screen_CellChanged(x, y) && !state.redraw) continue;
 
 			int cx = x * cw;
 			int cy = y * ch;
@@ -244,8 +224,6 @@ 		.loadTexture    = &LoadTexture,
 		.freeTexture    = &FreeTexture,
 		.getTextureSize = &GetTextureSize,
 		.onWindowResize = &OnWindowResize,
-		.onScreenUpdate = &OnScreenUpdate,
-		.onCellChange   = &OnCellChange,
 		.render         = &Render
 	};
 }




diff --git a/source/backends/stub.c b/source/backends/stub.c
index edad0a2e87c592fdade2d35c224ce2e789f300ad..57288d847ddb4b49033187c7fa7e981dbb507db0 100644
--- a/source/backends/stub.c
+++ b/source/backends/stub.c
@@ -33,15 +33,6 @@ static void OnWindowResize(void) {
 	
 }
 
-static void OnScreenUpdate(void) {
-	
-}
-
-static void OnCellChange(int x, int y) {
-	(void) x;
-	(void) y;
-}
-
 static void Render(void) {
 	
 }
@@ -55,8 +46,6 @@ 		.loadTexture    = &LoadTexture,
 		.freeTexture    = &FreeTexture,
 		.getTextureSize = &GetTextureSize,
 		.onWindowResize = &OnWindowResize,
-		.onScreenUpdate = &OnScreenUpdate,
-		.onCellChange   = &OnCellChange,
 		.render         = &Render
 	};
 }




diff --git a/source/buffer.c b/source/buffer.c
index ebf1c839d295a74f3a3bd20de5deb5f04398ea66..6a4ddbe6f52732a937927eb3c749ef0385eb6a26 100644
--- a/source/buffer.c
+++ b/source/buffer.c
@@ -1,6 +1,5 @@
 #include "mem.h"
 #include "buffer.h"
-#include "backend.h"
 
 BufAttr BufAttr_Default(void) {
 	return (BufAttr) {
@@ -25,9 +24,8 @@ 	for (int i = 0; i < width * height; ++ i) {
 		ret.buf[i] = FromChar(0);
 	}
 
-	ret.width       = width;
-	ret.height      = height;
-	ret.isScreenBuf = false;
+	ret.width  = width;
+	ret.height = height;
 	return ret;
 }
 
@@ -77,13 +75,7 @@ 	BufCell* ptr = Buffer_Get(buf, x, y);
 
 	if (!ptr) return;
 
-	bool change = !Buffer_CellEq(*ptr, cell);
-
 	*ptr = cell;
-
-	if (buf->isScreenBuf && change) {
-		Backend_OnCellChange(x, y);
-	}
 }
 
 void Buffer_InvertCell(Buffer* buf, int x, int y) {
@@ -92,10 +84,6 @@
 	if (!cell) return;
 
 	cell->attr.invert = !cell->attr.invert;
-
-	if (buf->isScreenBuf) {
-		Backend_OnCellChange(x, y);
-	}
 }
 
 void Buffer_Clear(Buffer* buf) {
@@ -118,13 +106,7 @@
 			int sx = ix + clip.x;
 			int sy = iy + clip.y;
 
-			BufCell* cell = Buffer_Get(src, sx, sy);
-
-			if (!Buffer_CellEq(*Buffer_Get(dest, x + ix, y + iy), *cell) && dest->isScreenBuf) {
-				Backend_OnCellChange(x + ix, y + iy);
-			}
-
-			*Buffer_Get(dest, x + ix, y + iy) = *cell;
+			*Buffer_Get(dest, x + ix, y + iy) = *Buffer_Get(src, sx, sy);
 		}
 	}
 }




diff --git a/source/buffer.h b/source/buffer.h
index bfa2934a736b262bc1b474e2d6356df951a81d16..d3938aa7002ba9202e0531c06e16122b4b2b0207 100644
--- a/source/buffer.h
+++ b/source/buffer.h
@@ -34,7 +34,6 @@ typedef struct {
 	BufCell* buf;
 	int      width;
 	int      height;
-	bool     isScreenBuf;
 } Buffer;
 
 BufAttr BufAttr_Default(void);




diff --git a/source/interpreter/vt100.c b/source/interpreter/vt100.c
index 61efd0007b01821f2166967890f5d5d73bba65bd..c892111233fb9638d0f72f65d1c562b883d992d4 100644
--- a/source/interpreter/vt100.c
+++ b/source/interpreter/vt100.c
@@ -229,7 +229,7 @@ 				case 1002: break; // TODO: use cell motion mouse tracking
 				case 1003: break; // TODO: use all motion mouse tracking
 				case 1048: break; // TODO: save cursor
 				case 1049: break; // TODO: save cursor & use alternate screen buffer
-				default: printf("Unsupported: %sh\n", param);
+				default: printf("Unsupported: %dh\n", param);
 			}
 			break;
 		}
@@ -244,13 +244,13 @@ 				case 12:   terminal->blinkCursor = false; break;
 				case 25:   terminal->showCursor  = false; break;
 				case 1047:
 				case 47:   break; // TODO: use normal screen buffer
-				case 1000: this->mouseMode = OFF; break;
+				case 1000: this->mouseMode = MOUSE_OFF; break;
 				case 1001: break; // TODO: do not use hilite motion mouse tracking
 				case 1002: break; // TODO: do not use cell motion mouse tracking
 				case 1003: break; // TODO: do not use all motion mouse tracking
 				case 1048: break; // TODO: restore cursor
 				case 1049: break; // TODO: restore cursor & use normal screen buffer
-				default: printf("Unsupported: %sh\n", param);
+				default: printf("Unsupported: %dl\n", param);
 			}
 			break;
 		}




diff --git a/source/screen.c b/source/screen.c
index 14d103107708a433917451be47d1ad8a99b3fea5..8155d07e2a0200f3bb47530e224741114784de5c 100644
--- a/source/screen.c
+++ b/source/screen.c
@@ -26,9 +26,6 @@ 	Font_CharSize(&screen.font, &cw, &ch);
 
 	screen.old    = Buffer_New(video.windows[0].width / cw, video.windows[0].height / ch);
 	screen.buffer = Buffer_New(video.windows[0].width / cw, video.windows[0].height / ch);
-	screen.buffer.isScreenBuf = true;
-
-	Backend_OnScreenUpdate();
 }
 
 void Screen_Free(void) {
@@ -47,26 +44,19 @@
 	assert(0);
 }
 
+bool Screen_CellChanged(int x, int y) {
+	BufCell* a = Buffer_Get(&screen.old,    x, y);
+	BufCell* b = Buffer_Get(&screen.buffer, x, y);
+
+	if (!a || !b) return false;
+
+	return !Buffer_CellEq(*a, *b);
+}
+
 void Screen_Render(void) {
-// 	int cw;
-// 	int ch;
-// 	Font_CharSize(&screen.font, &cw, &ch);
-// 
-// 	for (int y = 0; y < screen.buffer.height; ++ y) {
-// 		for (int x = 0; x < screen.buffer.width; ++ x) {
-// 			int cx = x * cw;
-// 			int cy = y * ch;
-// 
-// 			BufCell* cell = Buffer_Get(&screen.buffer, x, y);
-// 
-// 			ColourRGB fg = GetColour(true,  cell->fgMode, cell->fg);
-// 			ColourRGB bg = GetColour(false, cell->bgMode, cell->bg);
-// 
-// 			Rect   rect = {cx, cy, cw, ch};
-// 			Colour c    = (Colour) {bg.r, bg.g, bg.b, 255};
-// 			Backend_RenderRect(rect, c);
-// 
-// 			Font_RenderChar(&screen.font, cell->ch, cx, cy, fg);
-// 		}
-// 	}
+	Backend_Render();
+
+	Rect clip = {0, 0, screen.buffer.width, screen.buffer.height};
+
+	Buffer_Blit(&screen.old, &screen.buffer, 0, 0, clip);
 }




diff --git a/source/screen.h b/source/screen.h
index 1a374cc7276b63743f654f4fcde10f14f5d4c500..acd3e07ce8a6eb3c06a9e7cc8cc2da351508d8f3 100644
--- a/source/screen.h
+++ b/source/screen.h
@@ -15,6 +15,7 @@
 void      Screen_Init(void);
 void      Screen_Free(void);
 ColourRGB Screen_GetColour(bool fg, uint8_t mode, BufCol col);
+bool      Screen_CellChanged(int x, int y);
 void      Screen_Render(void);
 
 #endif