Implement stroking a path with nv_path_rendering
Initialize the path stroke properties in the GrGLPath constructor.
Use StencilStrokePath and CoverStrokePath to stroke the path.
The order of the GL calls is:
1. StencilFill, if needed
2. StencilStroke, if needed
2a. CoverStroke, if stroke was applied
2b. CoverFill, if stroke was not applied
The reason for not pairing StencilFill + CoverFill, StencilStroke +
CoverStroke is that Skia API does not allow separate fill and stroke
color within one call. Covering the stroke bounding box should also
cover the fill bounding box.
Causes different rendering in gm/dashcubics due to different rendering
algorithm. (?) (TODO: this should be resolved somehow.)
R=bsalomon@google.com, markkilgard@gmail.com, cdalton@nvidia.com
Author: kkinnunen@nvidia.com
Review URL: https://codereview.chromium.org/23440049
git-svn-id: http://skia.googlecode.com/svn/trunk@11672 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/GrGLPath.cpp b/src/gpu/gl/GrGLPath.cpp
index c5a4425..c85644e 100644
--- a/src/gpu/gl/GrGLPath.cpp
+++ b/src/gpu/gl/GrGLPath.cpp
@@ -8,6 +8,7 @@
#include "GrGLPath.h"
#include "GrGpuGL.h"
+#include "SkStrokeRec.h"
#define GPUGL static_cast<GrGpuGL*>(this->getGpu())
@@ -15,7 +16,7 @@
#define GL_CALL_RET(R, X) GR_GL_CALL_RET(GPUGL->glInterface(), R, X)
namespace {
-inline GrGLubyte verb_to_gl_path_cmd(const SkPath::Verb verb) {
+inline GrGLubyte verb_to_gl_path_cmd(SkPath::Verb verb) {
static const GrGLubyte gTable[] = {
GR_GL_MOVE_TO,
GR_GL_LINE_TO,
@@ -35,7 +36,7 @@
}
#ifdef SK_DEBUG
-inline int num_pts(const SkPath::Verb verb) {
+inline int num_pts(SkPath::Verb verb) {
static const int gTable[] = {
1, // move
1, // line
@@ -54,11 +55,39 @@
return gTable[verb];
}
#endif
+
+inline GrGLenum join_to_gl_join(SkPaint::Join join) {
+ static GrGLenum gSkJoinsToGrGLJoins[] = {
+ GR_GL_MITER_REVERT,
+ GR_GL_ROUND,
+ GR_GL_BEVEL
+ };
+ return gSkJoinsToGrGLJoins[join];
+ GR_STATIC_ASSERT(0 == SkPaint::kMiter_Join);
+ GR_STATIC_ASSERT(1 == SkPaint::kRound_Join);
+ GR_STATIC_ASSERT(2 == SkPaint::kBevel_Join);
+ GR_STATIC_ASSERT(GR_ARRAY_COUNT(gSkJoinsToGrGLJoins) == SkPaint::kJoinCount);
+}
+
+inline GrGLenum cap_to_gl_cap(SkPaint::Cap cap) {
+ static GrGLenum gSkCapsToGrGLCaps[] = {
+ GR_GL_FLAT,
+ GR_GL_ROUND,
+ GR_GL_SQUARE
+ };
+ return gSkCapsToGrGLCaps[cap];
+ GR_STATIC_ASSERT(0 == SkPaint::kButt_Cap);
+ GR_STATIC_ASSERT(1 == SkPaint::kRound_Cap);
+ GR_STATIC_ASSERT(2 == SkPaint::kSquare_Cap);
+ GR_STATIC_ASSERT(GR_ARRAY_COUNT(gSkCapsToGrGLCaps) == SkPaint::kCapCount);
+}
+
}
static const bool kIsWrapped = false; // The constructor creates the GL path object.
-GrGLPath::GrGLPath(GrGpuGL* gpu, const SkPath& path) : INHERITED(gpu, kIsWrapped) {
+GrGLPath::GrGLPath(GrGpuGL* gpu, const SkPath& path, const SkStrokeRec& stroke)
+ : INHERITED(gpu, kIsWrapped, stroke) {
#ifndef SK_SCALAR_IS_FLOAT
GrCrash("Assumes scalar is float.");
#endif
@@ -90,6 +119,19 @@
verbCnt, &pathCommands[0],
2 * pointCnt, GR_GL_FLOAT, &pathPoints[0]));
fBounds = path.getBounds();
+
+ if (stroke.needToApply()) {
+ GL_CALL(PathParameterf(fPathID, GR_GL_PATH_STROKE_WIDTH, SkScalarToFloat(stroke.getWidth())));
+ GL_CALL(PathParameterf(fPathID, GR_GL_PATH_MITER_LIMIT, SkScalarToFloat(stroke.getMiter())));
+ GrGLenum join = join_to_gl_join(stroke.getJoin());
+ GL_CALL(PathParameteri(fPathID, GR_GL_PATH_JOIN_STYLE, join));
+ GrGLenum cap = cap_to_gl_cap(stroke.getCap());
+ GL_CALL(PathParameteri(fPathID, GR_GL_PATH_INITIAL_END_CAP, cap));
+ GL_CALL(PathParameteri(fPathID, GR_GL_PATH_TERMINAL_END_CAP, cap));
+
+ // FIXME: try to account for stroking, without rasterizing the stroke.
+ fBounds.outset(SkScalarToFloat(stroke.getWidth()), SkScalarToFloat(stroke.getWidth()));
+ }
}
GrGLPath::~GrGLPath() {