clipTriangles method
void
clipTriangles(
- Float32List vertices,
- int verticesLength,
- Int16List triangles,
- int trianglesLength,
- Float32List uvs,
- Color light,
- Color dark,
- bool twoColor
Implementation
void clipTriangles(
Float32List vertices,
int verticesLength,
Int16List triangles,
int trianglesLength,
Float32List uvs,
Color light,
Color dark,
bool twoColor) {
final Float32List clipOutput = this.clipOutput as Float32List,
clippedVertices = this.clippedVertices as Float32List;
final Int16List clippedTriangles =
Int16List.fromList(this.clippedTriangles);
final List<Float32List>? polygons = clippingPolygons;
final int polygonsCount = clippingPolygons!.length;
final int vertexSize = twoColor ? 12 : 8;
int index = 0;
clippedVertices.length = 0;
clippedTriangles.length = 0;
outer:
for (int i = 0; i < trianglesLength; i += 3) {
int vertexOffset = triangles[i] << 1;
final double x1 = vertices[vertexOffset], y1 = vertices[vertexOffset + 1];
final double u1 = uvs[vertexOffset], v1 = uvs[vertexOffset + 1];
vertexOffset = triangles[i + 1] << 1;
final double x2 = vertices[vertexOffset], y2 = vertices[vertexOffset + 1];
final double u2 = uvs[vertexOffset], v2 = uvs[vertexOffset + 1];
vertexOffset = triangles[i + 2] << 1;
final double x3 = vertices[vertexOffset], y3 = vertices[vertexOffset + 1];
final double u3 = uvs[vertexOffset], v3 = uvs[vertexOffset + 1];
for (int p = 0; p < polygonsCount; p++) {
int s = clippedVertices.length;
if (clip(x1, y1, x2, y2, x3, y3, polygons![p], clipOutput)) {
final int clipOutputLength = clipOutput.length;
if (clipOutputLength == 0) continue;
final double d0 = y2 - y3, d1 = x3 - x2, d2 = x1 - x3, d4 = y3 - y1;
final double d = 1 / (d0 * d2 + d1 * (y1 - y3));
int clipOutputCount = clipOutputLength >> 1;
final Float32List clipOutputItems = this.clipOutput as Float32List;
final Float32List clippedVerticesItems =
ArrayUtils.copyWithNewArraySize(
clippedVertices,
s + clipOutputCount * vertexSize,
double.infinity) as Float32List;
for (int ii = 0; ii < clipOutputLength; ii += 2) {
final double x = clipOutputItems[ii], y = clipOutputItems[ii + 1];
clippedVerticesItems[s] = x;
clippedVerticesItems[s + 1] = y;
clippedVerticesItems[s + 2] = light.r;
clippedVerticesItems[s + 3] = light.g;
clippedVerticesItems[s + 4] = light.b;
clippedVerticesItems[s + 5] = light.a;
final double c0 = x - x3, c1 = y - y3;
final double a = (d0 * c0 + d1 * c1) * d;
final double b = (d4 * c0 + d2 * c1) * d;
final double c = 1 - a - b;
clippedVerticesItems[s + 6] = u1 * a + u2 * b + u3 * c;
clippedVerticesItems[s + 7] = v1 * a + v2 * b + v3 * c;
if (twoColor) {
clippedVerticesItems[s + 8] = dark.r;
clippedVerticesItems[s + 9] = dark.g;
clippedVerticesItems[s + 10] = dark.b;
clippedVerticesItems[s + 11] = dark.a;
}
s += vertexSize;
}
s = clippedTriangles.length;
final Int16List clippedTrianglesItems = Int16List.fromList(
ArrayUtils.copyWithNewArraySize(
clippedTriangles, s + 3 * (clipOutputCount - 2), -1));
clipOutputCount--;
for (int ii = 1; ii < clipOutputCount; ii++) {
clippedTrianglesItems[s] = index;
clippedTrianglesItems[s + 1] = (index + ii);
clippedTrianglesItems[s + 2] = (index + ii + 1);
s += 3;
}
index += clipOutputCount + 1;
} else {
final Float32List clippedVerticesItems =
ArrayUtils.copyWithNewArraySize(
clippedVertices, s + 3 * vertexSize, double.infinity)
as Float32List;
clippedVerticesItems[s] = x1;
clippedVerticesItems[s + 1] = y1;
clippedVerticesItems[s + 2] = light.r;
clippedVerticesItems[s + 3] = light.g;
clippedVerticesItems[s + 4] = light.b;
clippedVerticesItems[s + 5] = light.a;
if (!twoColor) {
clippedVerticesItems[s + 6] = u1;
clippedVerticesItems[s + 7] = v1;
clippedVerticesItems[s + 8] = x2;
clippedVerticesItems[s + 9] = y2;
clippedVerticesItems[s + 10] = light.r;
clippedVerticesItems[s + 11] = light.g;
clippedVerticesItems[s + 12] = light.b;
clippedVerticesItems[s + 13] = light.a;
clippedVerticesItems[s + 14] = u2;
clippedVerticesItems[s + 15] = v2;
clippedVerticesItems[s + 16] = x3;
clippedVerticesItems[s + 17] = y3;
clippedVerticesItems[s + 18] = light.r;
clippedVerticesItems[s + 19] = light.g;
clippedVerticesItems[s + 20] = light.b;
clippedVerticesItems[s + 21] = light.a;
clippedVerticesItems[s + 22] = u3;
clippedVerticesItems[s + 23] = v3;
} else {
clippedVerticesItems[s + 6] = u1;
clippedVerticesItems[s + 7] = v1;
clippedVerticesItems[s + 8] = dark.r;
clippedVerticesItems[s + 9] = dark.g;
clippedVerticesItems[s + 10] = dark.b;
clippedVerticesItems[s + 11] = dark.a;
clippedVerticesItems[s + 12] = x2;
clippedVerticesItems[s + 13] = y2;
clippedVerticesItems[s + 14] = light.r;
clippedVerticesItems[s + 15] = light.g;
clippedVerticesItems[s + 16] = light.b;
clippedVerticesItems[s + 17] = light.a;
clippedVerticesItems[s + 18] = u2;
clippedVerticesItems[s + 19] = v2;
clippedVerticesItems[s + 20] = dark.r;
clippedVerticesItems[s + 21] = dark.g;
clippedVerticesItems[s + 22] = dark.b;
clippedVerticesItems[s + 23] = dark.a;
clippedVerticesItems[s + 24] = x3;
clippedVerticesItems[s + 25] = y3;
clippedVerticesItems[s + 26] = light.r;
clippedVerticesItems[s + 27] = light.g;
clippedVerticesItems[s + 28] = light.b;
clippedVerticesItems[s + 29] = light.a;
clippedVerticesItems[s + 30] = u3;
clippedVerticesItems[s + 31] = v3;
clippedVerticesItems[s + 32] = dark.r;
clippedVerticesItems[s + 33] = dark.g;
clippedVerticesItems[s + 34] = dark.b;
clippedVerticesItems[s + 35] = dark.a;
}
s = clippedTriangles.length;
final Int16List clippedTrianglesItems = Int16List.fromList(
ArrayUtils.copyWithNewArraySize(clippedTriangles, s + 3, -1));
clippedTrianglesItems[s] = index;
clippedTrianglesItems[s + 1] = (index + 1);
clippedTrianglesItems[s + 2] = (index + 2);
index += 3;
continue outer;
}
}
}
}