void GrGLConvexPolyEffect::emitCode(EmitArgs& args) {
const GrConvexPolyEffect& cpe = args.fFp.cast<GrConvexPolyEffect>();
const char *edgeArrayName;
fEdgeUniform = args.fUniformHandler->addUniformArray(kFragment_GrShaderFlag,
kVec3f_GrSLType,
kDefault_GrSLPrecision,
"edges",
cpe.getEdgeCount(),
&edgeArrayName);
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
fragBuilder->codeAppend("\t\tfloat alpha = 1.0;\n");
fragBuilder->codeAppend("\t\tfloat edge;\n");
const char* fragmentPos = fragBuilder->fragmentPosition();
for (int i = 0; i < cpe.getEdgeCount(); ++i) {
fragBuilder->codeAppendf("\t\tedge = dot(%s[%d], vec3(%s.x, %s.y, 1));\n",
edgeArrayName, i, fragmentPos, fragmentPos);
if (GrProcessorEdgeTypeIsAA(cpe.getEdgeType())) {
fragBuilder->codeAppend("\t\tedge = clamp(edge, 0.0, 1.0);\n");
} else {
fragBuilder->codeAppend("\t\tedge = edge >= 0.5 ? 1.0 : 0.0;\n");
}
fragBuilder->codeAppend("\t\talpha *= edge;\n");
}
if (GrProcessorEdgeTypeIsInverseFill(cpe.getEdgeType())) {
fragBuilder->codeAppend("\talpha = 1.0 - alpha;\n");
}
fragBuilder->codeAppendf("\t%s = %s;\n", args.fOutputColor,
(GrGLSLExpr4(args.fInputColor) * GrGLSLExpr1("alpha")).c_str());
}
void GLDitherEffect::emitCode(EmitArgs& args) {
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
// Generate a random number based on the fragment position. For this
// random number generator, we use the "GLSL rand" function
// that seems to be floating around on the internet. It works under
// the assumption that sin(<big number>) oscillates with high frequency
// and sampling it will generate "randomness". Since we're using this
// for rendering and not cryptography it should be OK.
// For each channel c, add the random offset to the pixel to either bump
// it up or let it remain constant during quantization.
fragBuilder->codeAppendf("\t\tfloat r = "
"fract(sin(dot(%s.xy ,vec2(12.9898,78.233))) * 43758.5453);\n",
fragBuilder->fragmentPosition());
fragBuilder->codeAppendf("\t\t%s = (1.0/255.0) * vec4(r, r, r, r) + %s;\n",
args.fOutputColor, GrGLSLExpr4(args.fInputColor).c_str());
}
void GLAARectEffect::emitCode(EmitArgs& args) {
const AARectEffect& aare = args.fFp.cast<AARectEffect>();
const char *rectName;
// The rect uniform's xyzw refer to (left + 0.5, top + 0.5, right - 0.5, bottom - 0.5),
// respectively.
fRectUniform = args.fUniformHandler->addUniform(kFragment_GrShaderFlag,
kVec4f_GrSLType,
kDefault_GrSLPrecision,
"rect",
&rectName);
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
const char* fragmentPos = fragBuilder->fragmentPosition();
if (GrProcessorEdgeTypeIsAA(aare.getEdgeType())) {
// The amount of coverage removed in x and y by the edges is computed as a pair of negative
// numbers, xSub and ySub.
fragBuilder->codeAppend("\t\tfloat xSub, ySub;\n");
fragBuilder->codeAppendf("\t\txSub = min(%s.x - %s.x, 0.0);\n", fragmentPos, rectName);
fragBuilder->codeAppendf("\t\txSub += min(%s.z - %s.x, 0.0);\n", rectName, fragmentPos);
fragBuilder->codeAppendf("\t\tySub = min(%s.y - %s.y, 0.0);\n", fragmentPos, rectName);
fragBuilder->codeAppendf("\t\tySub += min(%s.w - %s.y, 0.0);\n", rectName, fragmentPos);
// Now compute coverage in x and y and multiply them to get the fraction of the pixel
// covered.
fragBuilder->codeAppendf("\t\tfloat alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));\n");
} else {
fragBuilder->codeAppendf("\t\tfloat alpha = 1.0;\n");
fragBuilder->codeAppendf("\t\talpha *= (%s.x - %s.x) > -0.5 ? 1.0 : 0.0;\n", fragmentPos, rectName);
fragBuilder->codeAppendf("\t\talpha *= (%s.z - %s.x) > -0.5 ? 1.0 : 0.0;\n", rectName, fragmentPos);
fragBuilder->codeAppendf("\t\talpha *= (%s.y - %s.y) > -0.5 ? 1.0 : 0.0;\n", fragmentPos, rectName);
fragBuilder->codeAppendf("\t\talpha *= (%s.w - %s.y) > -0.5 ? 1.0 : 0.0;\n", rectName, fragmentPos);
}
if (GrProcessorEdgeTypeIsInverseFill(aare.getEdgeType())) {
fragBuilder->codeAppend("\t\talpha = 1.0 - alpha;\n");
}
fragBuilder->codeAppendf("\t\t%s = %s;\n", args.fOutputColor,
(GrGLSLExpr4(args.fInputColor) * GrGLSLExpr1("alpha")).c_str());
}
void GrGLCircleBlurFragmentProcessor::emitCode(EmitArgs& args) {
const char *dataName;
// The data is formatted as:
// x,y - the center of the circle
// z - the distance at which the intensity starts falling off (e.g., the start of the table)
// w - the inverse of the profile texture size
fDataUniform = args.fUniformHandler->addUniform(kFragment_GrShaderFlag,
kVec4f_GrSLType,
kDefault_GrSLPrecision,
"data",
&dataName);
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
const char *fragmentPos = fragBuilder->fragmentPosition();
if (args.fInputColor) {
fragBuilder->codeAppendf("vec4 src=%s;", args.fInputColor);
} else {
fragBuilder->codeAppendf("vec4 src=vec4(1);");
}
// We just want to compute "length(vec) - %s.z + 0.5) * %s.w" but need to rearrange
// for precision
fragBuilder->codeAppendf("vec2 vec = vec2( (%s.x - %s.x) * %s.w , (%s.y - %s.y) * %s.w );",
fragmentPos, dataName, dataName,
fragmentPos, dataName, dataName);
fragBuilder->codeAppendf("float dist = length(vec) + ( 0.5 - %s.z ) * %s.w;",
dataName, dataName);
fragBuilder->codeAppendf("float intensity = ");
fragBuilder->appendTextureLookup(args.fTexSamplers[0], "vec2(dist, 0.5)");
fragBuilder->codeAppend(".a;");
fragBuilder->codeAppendf("%s = src * intensity;\n", args.fOutputColor );
}