Fix hairline pathrenderer for Nexus-10. Switches to using additional
geometry and passing in the coverage value instead.
BUG=
R=robertphillips@google.com, bsalomon@google.com
Author: jvanverth@google.com
Review URL: https://chromiumcodereview.appspot.com/22486003
git-svn-id: http://skia.googlecode.com/svn/trunk@10640 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/GrAAHairLinePathRenderer.cpp b/src/gpu/GrAAHairLinePathRenderer.cpp
index c1f951a..33c2ac3 100644
--- a/src/gpu/GrAAHairLinePathRenderer.cpp
+++ b/src/gpu/GrAAHairLinePathRenderer.cpp
@@ -29,15 +29,20 @@
static const int kVertsPerQuad = 5;
static const int kIdxsPerQuad = 9;
-static const int kVertsPerLineSeg = 4;
-static const int kIdxsPerLineSeg = 6;
+static const int kVertsPerLineSeg = 6;
+static const int kIdxsPerLineSeg = 12;
static const int kNumQuadsInIdxBuffer = 256;
static const size_t kQuadIdxSBufize = kIdxsPerQuad *
sizeof(uint16_t) *
kNumQuadsInIdxBuffer;
-bool push_quad_index_data(GrIndexBuffer* qIdxBuffer) {
+static const int kNumLineSegsInIdxBuffer = 256;
+static const size_t kLineSegIdxSBufize = kIdxsPerLineSeg *
+ sizeof(uint16_t) *
+ kNumLineSegsInIdxBuffer;
+
+static bool push_quad_index_data(GrIndexBuffer* qIdxBuffer) {
uint16_t* data = (uint16_t*) qIdxBuffer->lock();
bool tempData = NULL == data;
if (tempData) {
@@ -78,22 +83,66 @@
return true;
}
}
+
+static bool push_line_index_data(GrIndexBuffer* lIdxBuffer) {
+ uint16_t* data = (uint16_t*) lIdxBuffer->lock();
+ bool tempData = NULL == data;
+ if (tempData) {
+ data = SkNEW_ARRAY(uint16_t, kNumLineSegsInIdxBuffer * kIdxsPerLineSeg);
+ }
+ for (int i = 0; i < kNumLineSegsInIdxBuffer; ++i) {
+ // Each line segment is rendered as two quads, with alpha = 1 along the
+ // spine of the segment, and alpha = 0 along the outer edges, represented
+ // horizontally (i.e., the line equation is t*(p1-p0) + p0)
+ //
+ // p4 p5
+ // p0 p1
+ // p2 p3
+ //
+ // Each is drawn as four triangles specified by these 12 indices:
+ int baseIdx = i * kIdxsPerLineSeg;
+ uint16_t baseVert = (uint16_t)(i * kVertsPerLineSeg);
+ data[0 + baseIdx] = baseVert + 0; // p0
+ data[1 + baseIdx] = baseVert + 1; // p1
+ data[2 + baseIdx] = baseVert + 2; // p2
+
+ data[3 + baseIdx] = baseVert + 2; // p2
+ data[4 + baseIdx] = baseVert + 1; // p1
+ data[5 + baseIdx] = baseVert + 3; // p3
+
+ data[6 + baseIdx] = baseVert + 0; // p0
+ data[7 + baseIdx] = baseVert + 5; // p5
+ data[8 + baseIdx] = baseVert + 1; // p1
+
+ data[9 + baseIdx] = baseVert + 0; // p0
+ data[10+ baseIdx] = baseVert + 4; // p4
+ data[11+ baseIdx] = baseVert + 5; // p5
+ }
+ if (tempData) {
+ bool ret = lIdxBuffer->updateData(data, kLineSegIdxSBufize);
+ delete[] data;
+ return ret;
+ } else {
+ lIdxBuffer->unlock();
+ return true;
+ }
+}
}
GrPathRenderer* GrAAHairLinePathRenderer::Create(GrContext* context) {
- const GrIndexBuffer* lIdxBuffer = context->getQuadIndexBuffer();
- if (NULL == lIdxBuffer) {
- return NULL;
- }
GrGpu* gpu = context->getGpu();
GrIndexBuffer* qIdxBuf = gpu->createIndexBuffer(kQuadIdxSBufize, false);
SkAutoTUnref<GrIndexBuffer> qIdxBuffer(qIdxBuf);
- if (NULL == qIdxBuf ||
- !push_quad_index_data(qIdxBuf)) {
+ if (NULL == qIdxBuf || !push_quad_index_data(qIdxBuf)) {
+ return NULL;
+ }
+ GrIndexBuffer* lIdxBuf = gpu->createIndexBuffer(kLineSegIdxSBufize, false);
+ SkAutoTUnref<GrIndexBuffer> lIdxBuffer(lIdxBuf);
+ if (NULL == lIdxBuf || !push_line_index_data(lIdxBuf)) {
return NULL;
}
return SkNEW_ARGS(GrAAHairLinePathRenderer,
- (context, lIdxBuffer, qIdxBuf));
+ (context, lIdxBuf, qIdxBuf));
}
GrAAHairLinePathRenderer::GrAAHairLinePathRenderer(
@@ -436,9 +485,7 @@
GrPoint fPos;
union {
struct {
- SkScalar fA;
- SkScalar fB;
- SkScalar fC;
+ SkScalar fCoverage;
} fLine;
struct {
SkScalar fK;
@@ -661,17 +708,17 @@
if (orthVec.setLength(SK_Scalar1)) {
orthVec.setOrthog(orthVec);
- SkScalar lineC = -(a.dot(orthVec));
for (int i = 0; i < kVertsPerLineSeg; ++i) {
- (*vert)[i].fPos = (i < 2) ? a : b;
- if (0 == i || 3 == i) {
- (*vert)[i].fPos -= orthVec;
- } else {
+ (*vert)[i].fPos = (i & 0x1) ? b : a;
+ if (i & 0x2) {
(*vert)[i].fPos += orthVec;
+ (*vert)[i].fLine.fCoverage = 0;
+ } else if (i & 0x4) {
+ (*vert)[i].fPos -= orthVec;
+ (*vert)[i].fLine.fCoverage = 0;
+ } else {
+ (*vert)[i].fLine.fCoverage = SK_Scalar1;
}
- (*vert)[i].fLine.fA = orthVec.fX;
- (*vert)[i].fLine.fB = orthVec.fY;
- (*vert)[i].fLine.fC = lineC;
}
if (NULL != toSrc) {
toSrc->mapPointsWithStride(&(*vert)->fPos,
@@ -684,6 +731,8 @@
(*vert)[1].fPos.set(SK_ScalarMax, SK_ScalarMax);
(*vert)[2].fPos.set(SK_ScalarMax, SK_ScalarMax);
(*vert)[3].fPos.set(SK_ScalarMax, SK_ScalarMax);
+ (*vert)[4].fPos.set(SK_ScalarMax, SK_ScalarMax);
+ (*vert)[5].fPos.set(SK_ScalarMax, SK_ScalarMax);
}
*vert += kVertsPerLineSeg;
@@ -936,7 +985,7 @@
/**
* The output of this effect is a 1-pixel wide line.
- * Input is 2D implicit device coord line eq (a*x + b*y +c = 0). 4th component unused.
+ * Input is coverage relative to the line.
*/
class HairLineEdgeEffect : public GrEffect {
public:
@@ -978,9 +1027,7 @@
builder->addVarying(kVec4f_GrSLType, "HairLineEdge", &vsName, &fsName);
- builder->fsCodeAppendf("\t\tedgeAlpha = abs(dot(vec3(%s.xy,1), %s.xyz));\n",
- builder->fragmentPosition(), fsName);
- builder->fsCodeAppendf("\t\tedgeAlpha = max(1.0 - edgeAlpha, 0.0);\n");
+ builder->fsCodeAppendf("\t\tedgeAlpha = %s.x;\n", fsName);
SkString modulate;
GrGLSLModulatef<4>(&modulate, inputColor, "edgeAlpha");
@@ -1191,13 +1238,15 @@
#endif
{
+ // the fact we're using an effect to pass per-vertex coverage is kind of dumb,
+ // but necessary due to the shared vertex buffer
+ // TODO: refactor so that we render lines with a separate vertex buffer
GrDrawState::AutoRestoreEffects are(drawState);
target->setIndexSourceToBuffer(fLinesIndexBuffer);
int lines = 0;
- int nBufLines = fLinesIndexBuffer->maxQuads();
drawState->addCoverageEffect(hairLineEffect, kEdgeAttrIndex)->unref();
while (lines < lineCnt) {
- int n = GrMin(lineCnt - lines, nBufLines);
+ int n = GrMin(lineCnt - lines, kNumLineSegsInIdxBuffer);
target->drawIndexed(kTriangles_GrPrimitiveType,
kVertsPerLineSeg*lines, // startV
0, // startI