From a546388063a723771e3a6d588d428028536aed91 Mon Sep 17 00:00:00 2001
From: akallabeth <akallabeth@posteo.net>
Date: Wed, 20 Sep 2023 08:53:01 +0200
Subject: [PATCH] [gdi,line] clean up line functions

* Simplify CMake source detection
* Clean up code in line.c, add assertions
---
 libfreerdp/gdi/CMakeLists.txt | 22 +++--------
 libfreerdp/gdi/line.c         | 73 ++++++++++++++++++++---------------
 2 files changed, 48 insertions(+), 47 deletions(-)

diff --git a/libfreerdp/gdi/CMakeLists.txt b/libfreerdp/gdi/CMakeLists.txt
index 891e74338..97e1d27f9 100644
--- a/libfreerdp/gdi/CMakeLists.txt
+++ b/libfreerdp/gdi/CMakeLists.txt
@@ -20,22 +20,12 @@ set(MODULE_PREFIX "FREERDP_GDI")
 
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
 
-set(${MODULE_PREFIX}_SRCS
-	bitmap.c
-	brush.c
-	clipping.c
-	dc.c
-	drawing.c
-	line.c
-	pen.c
-	region.c
-	shape.c
-	graphics.c
-	graphics.h
-	gfx.c
-	video.c
-	gdi.c
-	gdi.h)
+file(GLOB ${MODULE_PREFIX}_SRCS
+	LIST_DIRECTORIES false
+	RELATIVE ${CMAKE_CURRENT_SOURCE_DIR}
+	CONFIGURE_DEPENDS
+	"*.[ch]"
+)
 
 freerdp_module_add(${${MODULE_PREFIX}_SRCS})
 
diff --git a/libfreerdp/gdi/line.c b/libfreerdp/gdi/line.c
index ce3d5b2b4..7c600dc1f 100644
--- a/libfreerdp/gdi/line.c
+++ b/libfreerdp/gdi/line.c
@@ -25,6 +25,8 @@
 #include <string.h>
 #include <stdlib.h>
 
+#include <winpr/assert.h>
+
 #include <freerdp/freerdp.h>
 #include <freerdp/gdi/gdi.h>
 #include <freerdp/gdi/pen.h>
@@ -37,6 +39,7 @@
 
 static BOOL gdi_rop_color(UINT32 rop, BYTE* pixelPtr, UINT32 pen, UINT32 format)
 {
+	WINPR_ASSERT(pixelPtr);
 	const UINT32 srcPixel = FreeRDPReadColor(pixelPtr, format);
 	UINT32 dstPixel;
 
@@ -115,30 +118,26 @@ static BOOL gdi_rop_color(UINT32 rop, BYTE* pixelPtr, UINT32 pen, UINT32 format)
 
 BOOL gdi_LineTo(HGDI_DC hdc, UINT32 nXEnd, UINT32 nYEnd)
 {
-	INT32 x, y;
-	INT32 x1, y1;
-	INT32 x2, y2;
-	INT32 e, e2;
-	INT32 dx, dy;
-	INT32 sx, sy;
-	INT32 bx1, by1;
-	INT32 bx2, by2;
-	HGDI_BITMAP bmp;
+	INT32 e2;
 	UINT32 pen;
-	INT32 rop2 = gdi_GetROP2(hdc);
-	x1 = hdc->pen->posX;
-	y1 = hdc->pen->posY;
-	x2 = nXEnd;
-	y2 = nYEnd;
-	dx = (x1 > x2) ? x1 - x2 : x2 - x1;
-	dy = (y1 > y2) ? y1 - y2 : y2 - y1;
-	sx = (x1 < x2) ? 1 : -1;
-	sy = (y1 < y2) ? 1 : -1;
-	e = dx - dy;
-	x = x1;
-	y = y1;
-	bmp = (HGDI_BITMAP)hdc->selectedObject;
 
+	WINPR_ASSERT(hdc);
+	const INT32 rop2 = gdi_GetROP2(hdc);
+
+	const INT32 x1 = hdc->pen->posX;
+	const INT32 y1 = hdc->pen->posY;
+	const INT32 x2 = nXEnd;
+	const INT32 y2 = nYEnd;
+	const INT32 dx = (x1 > x2) ? x1 - x2 : x2 - x1;
+	const INT32 dy = (y1 > y2) ? y1 - y2 : y2 - y1;
+	const INT32 sx = (x1 < x2) ? 1 : -1;
+	const INT32 sy = (y1 < y2) ? 1 : -1;
+	INT32 e = dx - dy;
+	INT32 x = x1;
+	INT32 y = y1;
+
+	WINPR_ASSERT(hdc->clip);
+	INT32 bx1, by1, bx2, by2;
 	if (hdc->clip->null)
 	{
 		bx1 = (x1 < x2) ? x1 : x2;
@@ -154,6 +153,9 @@ BOOL gdi_LineTo(HGDI_DC hdc, UINT32 nXEnd, UINT32 nYEnd)
 		by2 = by1 + hdc->clip->h - 1;
 	}
 
+	HGDI_BITMAP bmp = (HGDI_BITMAP)hdc->selectedObject;
+	WINPR_ASSERT(bmp);
+
 	bx1 = MAX(bx1, 0);
 	by1 = MAX(by1, 0);
 	bx2 = MIN(bx2, bmp->width - 1);
@@ -171,6 +173,7 @@ BOOL gdi_LineTo(HGDI_DC hdc, UINT32 nXEnd, UINT32 nYEnd)
 			if ((x >= bx1 && x <= bx2) && (y >= by1 && y <= by2))
 			{
 				BYTE* pixel = gdi_GetPointer(bmp, x, y);
+				WINPR_ASSERT(pixel);
 				gdi_rop_color(rop2, pixel, pen, bmp->format);
 			}
 		}
@@ -206,9 +209,10 @@ BOOL gdi_LineTo(HGDI_DC hdc, UINT32 nXEnd, UINT32 nYEnd)
  */
 BOOL gdi_PolylineTo(HGDI_DC hdc, GDI_POINT* lppt, DWORD cCount)
 {
-	DWORD i;
+	WINPR_ASSERT(hdc);
+	WINPR_ASSERT(lppt || (cCount == 0));
 
-	for (i = 0; i < cCount; i++)
+	for (DWORD i = 0; i < cCount; i++)
 	{
 		if (!gdi_LineTo(hdc, lppt[i].x, lppt[i].y))
 			return FALSE;
@@ -229,15 +233,17 @@ BOOL gdi_PolylineTo(HGDI_DC hdc, GDI_POINT* lppt, DWORD cCount)
  */
 BOOL gdi_Polyline(HGDI_DC hdc, GDI_POINT* lppt, UINT32 cPoints)
 {
+	WINPR_ASSERT(hdc);
+	WINPR_ASSERT(lppt || (cPoints == 0));
+
 	if (cPoints > 0)
 	{
-		UINT32 i;
-		GDI_POINT pt;
+		GDI_POINT pt = { 0 };
 
 		if (!gdi_MoveToEx(hdc, lppt[0].x, lppt[0].y, &pt))
 			return FALSE;
 
-		for (i = 0; i < cPoints; i++)
+		for (UINT32 i = 0; i < cPoints; i++)
 		{
 			if (!gdi_LineTo(hdc, lppt[i].x, lppt[i].y))
 				return FALSE;
@@ -263,12 +269,15 @@ BOOL gdi_Polyline(HGDI_DC hdc, GDI_POINT* lppt, UINT32 cPoints)
  */
 BOOL gdi_PolyPolyline(HGDI_DC hdc, GDI_POINT* lppt, UINT32* lpdwPolyPoints, DWORD cCount)
 {
-	UINT32 cPoints;
-	DWORD i, j = 0;
+	DWORD j = 0;
 
-	for (i = 0; i < cCount; i++)
+	WINPR_ASSERT(hdc);
+	WINPR_ASSERT(lppt || (cCount == 0));
+	WINPR_ASSERT(lpdwPolyPoints || (cCount == 0));
+
+	for (DWORD i = 0; i < cCount; i++)
 	{
-		cPoints = lpdwPolyPoints[i];
+		const UINT32 cPoints = lpdwPolyPoints[i];
 
 		if (!gdi_Polyline(hdc, &lppt[j], cPoints))
 			return FALSE;
@@ -289,6 +298,8 @@ BOOL gdi_PolyPolyline(HGDI_DC hdc, GDI_POINT* lppt, UINT32* lpdwPolyPoints, DWOR
 
 BOOL gdi_MoveToEx(HGDI_DC hdc, UINT32 X, UINT32 Y, HGDI_POINT lpPoint)
 {
+	WINPR_ASSERT(hdc);
+
 	if (lpPoint != NULL)
 	{
 		lpPoint->x = hdc->pen->posX;