Author: duncan
Date: 2005-10-03 06:47:08 -0400 (Mon, 03 Oct 2005)
New Revision: 51112
Modified:
trunk/libgdiplus/src/ChangeLog
trunk/libgdiplus/src/graphics-path.c
trunk/libgdiplus/src/graphics.c
Log:
2005-10-03 Duncan Mak <[EMAIL PROTECTED]>
* graphics.c (make_arcs):
* graphics-path.c (append_arcs): Helper functions for dividing
the arcs into smaller segments. Properly handles negative starting
angles and sweep angles.
* graphics-path.c (GdipAddPathArc, GdipAddPathPie):
* graphics.c (GdipDrawArc, make_pie): Simplified to make use of the
new helper functions.
Modified: trunk/libgdiplus/src/ChangeLog
===================================================================
--- trunk/libgdiplus/src/ChangeLog 2005-10-03 10:46:44 UTC (rev 51111)
+++ trunk/libgdiplus/src/ChangeLog 2005-10-03 10:47:08 UTC (rev 51112)
@@ -1,3 +1,14 @@
+2005-10-03 Duncan Mak <[EMAIL PROTECTED]>
+
+ * graphics.c (make_arcs):
+ * graphics-path.c (append_arcs): Helper functions for dividing
+ the arcs into smaller segments. Properly handles negative starting
+ angles and sweep angles.
+
+ * graphics-path.c (GdipAddPathArc, GdipAddPathPie):
+ * graphics.c (GdipDrawArc, make_pie): Simplified to make use of the
+ new helper functions.
+
2005-09-20 Jordi Mas i Hernandez <[EMAIL PROTECTED]>
* image.c, gdip.h, image.c: Creates the surface and then creates the
Modified: trunk/libgdiplus/src/graphics-path.c
===================================================================
--- trunk/libgdiplus/src/graphics-path.c 2005-10-03 10:46:44 UTC (rev
51111)
+++ trunk/libgdiplus/src/graphics-path.c 2005-10-03 10:47:08 UTC (rev
51112)
@@ -560,6 +560,7 @@
/* angles in radians */
float alpha = startAngle * PI / 180;
float beta = endAngle * PI / 180;
+ float sweep = abs (beta - alpha);
float delta = beta - alpha;
float bcp = 4.0 / 3 * (1 - cos (delta / 2)) / sin (delta / 2);
@@ -572,7 +573,7 @@
/* starting point */
double sx = cx + rx * cos_alpha;
double sy = cy + ry * sin_alpha;
-
+
/* move to the starting point if we're not continuing a curve */
if (start)
append (path, sx, sy, PathPointTypeLine);
@@ -586,27 +587,50 @@
cy + ry * sin_beta);
}
+static void
+append_arcs (GpPath *path, float x, float y, float width, float height, float
startAngle, float sweepAngle)
+{
+ int i;
+ float drawn = 0;
+ float endAngle = startAngle + sweepAngle;
+ int sign = (endAngle > 0) ? 1 : -1;
+ int increment = sign * 90;
+
+ if (abs (sweepAngle) >= 360) {
+ GdipAddPathEllipse (path, x, y, width, height);
+ return;
+ }
+
+ /* i is the number of sub-arcs drawn, each sub-arc can be at most 90
degrees.*/
+ /* there can be no more then 4 subarcs, ie. 90 + 90 + 90 + (something
less than 90) */
+ for (i = 0; i < 4; i++) {
+ float current = startAngle + drawn;
+
+ /* we've drawn enough */
+ if (abs (current) >= abs (endAngle))
+ break;
+
+ /* if we are not done yet */
+ float additional = abs (current + increment) < abs (endAngle) ?
+ increment : /* add the default increment */
+ endAngle - current; /* otherwise, add the
remainder */
+
+ append_arc (path,
+ (i == 0) ? TRUE : FALSE, /* only move to the
starting pt in the 1st iteration */
+ x, y, width, height, /* bounding rectangle */
+ current, current + additional);
+ drawn += additional;
+ }
+}
+
GpStatus
GdipAddPathArc (GpPath *path, float x, float y,
float width, float height, float startAngle, float sweepAngle)
{
- float endAngle = startAngle + sweepAngle;
- int i, sign = (endAngle > 0) ? 1 : -1;
-
g_return_val_if_fail (path != NULL, InvalidParameter);
- if (abs (sweepAngle) >= 360)
- return GdipAddPathEllipse (path, x, y, width, height);
-
/* draw the arcs */
- for (i = 0; i < abs (endAngle); i += 90) {
- append_arc (path,
- (i == 0) ? TRUE : FALSE, /* only move to the
starting pt in the 1st iteration */
- x, y, width, height, /* bounding rectangle */
- i * sign, /* start angle */
- (i + 90 < abs (endAngle)) ? (i + 90) * sign :
endAngle); /* sweep angle,
-
at most up to 90 degrees */
- }
+ append_arcs (path, x, y, width, height, startAngle, sweepAngle);
return Ok;
}
@@ -796,19 +820,8 @@
append (path, cx + rx * cos_alpha, cy + ry * sin_alpha,
PathPointTypeLine);
- /* draw arc */
- if (abs (sweepAngle) >= 360)
- return GdipAddPathEllipse (path, x, y, width, height);
-
/* draw the arcs */
- for (i = 0; i < abs (endAngle); i += 90) {
- append_arc (path,
- (i == 0) ? TRUE : FALSE, /* only move to the
starting pt in the 1st iteration */
- x, y, width, height, /* bounding rectangle */
- i * sign, /* start angle */
- (i + 90 < abs (endAngle)) ? (i + 90) * sign :
endAngle); /* sweep angle,
-
at most up to 90 degrees */
- }
+ append_arcs (path, x, y, width, height, startAngle, sweepAngle);
/* draw pie edge */
append (path, cx, cy, PathPointTypeLine);
Modified: trunk/libgdiplus/src/graphics.c
===================================================================
--- trunk/libgdiplus/src/graphics.c 2005-10-03 10:46:44 UTC (rev 51111)
+++ trunk/libgdiplus/src/graphics.c 2005-10-03 10:47:08 UTC (rev 51112)
@@ -164,7 +164,7 @@
*/
static void
make_arc (GpGraphics *graphics, bool start, float x, float y, float width,
- float height, float startAngle, float endAngle)
+ float height, float startAngle, float endAngle)
{
float rx = width / 2;
float ry = height / 2;
@@ -176,6 +176,7 @@
/* angles in radians */
float alpha = startAngle * PI / 180;
float beta = endAngle * PI / 180;
+ float sweep = abs (beta - alpha);
float delta = beta - alpha;
float bcp = 4.0 / 3 * (1 - cos (delta / 2)) / sin (delta /2);
@@ -188,7 +189,7 @@
/* starting point */
double sx = cx + rx * cos_alpha;
double sy = cy + ry * sin_alpha;
-
+
/* don't move to starting point if we're continuing an existing curve
*/
if (start)
cairo_move_to (graphics->ct, sx, sy);
@@ -203,6 +204,42 @@
}
static void
+make_arcs (GpGraphics *graphics, float x, float y, float width, float height,
float startAngle, float sweepAngle)
+{
+ int i;
+ float drawn = 0;
+ float endAngle = startAngle + sweepAngle;
+ int sign = (endAngle > 0) ? 1 : -1;
+ int increment = sign * 90;
+
+ if (abs (sweepAngle) >= 360) {
+ make_ellipse (graphics, x, y, width, height);
+ return;
+ }
+
+ /* i is the number of sub-arcs drawn, each sub-arc can be at most 90
degrees.*/
+ /* there can be no more then 4 subarcs, ie. 90 + 90 + 90 + (something
less than 90) */
+ for (i = 0; i < 4; i++) {
+ float current = startAngle + drawn;
+
+ /* we've drawn enough */
+ if (abs (current) >= abs (endAngle))
+ break;
+
+ /* if we are not done yet */
+ float additional = abs (current + increment) < abs (endAngle) ?
+ increment : /* add the default increment */
+ endAngle - current; /* otherwise, add the
remainder */
+
+ make_arc (graphics,
+ (i == 0) ? TRUE : FALSE, /* only move to the
starting pt in the 1st iteration */
+ x, y, width, height, /* bounding rectangle */
+ current, current + additional);
+ drawn += additional;
+ }
+}
+
+static void
make_pie (GpGraphics *graphics, float x, float y,
float width, float height, float startAngle, float sweepAngle)
{
@@ -213,10 +250,6 @@
float cx = x + rx;
float cy = y + ry;
- float endAngle = startAngle + sweepAngle;
-
- int i, sign = (sweepAngle > 0) ? 1 : -1;
-
/* angles in radians */
float alpha = startAngle * PI / 180;
@@ -231,22 +264,8 @@
cx + rx * cos_alpha,
cy + ry * sin_alpha);
- /* just make an ellipse if we're going a full 2 PI (360 degrees) */
- if (abs (sweepAngle) >= 360) {
- make_ellipse (graphics, x, y, width, height);
- return;
- }
-
/* draw the arcs */
- for (i = 0; i < abs (sweepAngle); i += 90) {
- make_arc (graphics,
- (i == 0) ? TRUE : FALSE, /* only move to the
starting pt in the 1st iteration */
- x, y, width, height, /* bounding rectangle */
- startAngle + i * sign, /* start angle */
- (i + 90 < abs (sweepAngle)) ?
- startAngle + (i + 90) * sign : endAngle); /* sweep
angle at most up to 90 degrees */
-
- }
+ make_arcs (graphics, x, y, width, height, startAngle, sweepAngle);
/* draws line back to center */
cairo_line_to (graphics->ct, cx, cy);
@@ -607,22 +626,8 @@
* have it set already.
*/
- /* just make an ellipse if we're going a full 360 degrees */
- if (abs (sweepAngle) >= 360)
- make_ellipse (graphics, x, y, width, height);
- else {
- int i, sign = (endAngle > 0) ? 1 : -1;
+ make_arcs (graphics, x, y, width, height, startAngle, sweepAngle);
- /* draw the arcs */
- for (i = 0; i < abs (endAngle); i += 90) {
- make_arc (graphics,
- (i == 0) ? TRUE : FALSE, /* only move to
the starting pt in the 1st iteration */
- x, y, width, height, /* bounding
rectangle */
- i * sign, /* start angle */
- (i + 90 < abs (endAngle)) ? (i + 90) * sign :
endAngle); /* sweep angle, at most up to 90 degrees */
- }
- }
-
/* We do pen setup just before stroking. */
gdip_pen_setup (graphics, pen);
cairo_stroke (graphics->ct);
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