From 6b2c3cd5bbc4c648d7293fb52b4dd0d817bf42e1 Mon Sep 17 00:00:00 2001 From: Alwinfy <20421383+Alwinfy@users.noreply.github.com> Date: Mon, 7 Nov 2022 02:53:15 -0500 Subject: [PATCH] Clean up line rendering code. Slightly hacky but works in the 99% case --- .../at/petrak/hexcasting/client/RenderLib.kt | 92 +++++++++++++++---- 1 file changed, 73 insertions(+), 19 deletions(-) diff --git a/Common/src/main/java/at/petrak/hexcasting/client/RenderLib.kt b/Common/src/main/java/at/petrak/hexcasting/client/RenderLib.kt index da6d39f4..fc0f7f5f 100644 --- a/Common/src/main/java/at/petrak/hexcasting/client/RenderLib.kt +++ b/Common/src/main/java/at/petrak/hexcasting/client/RenderLib.kt @@ -44,6 +44,8 @@ import kotlin.math.sin */ val NOISE: PerlinNoise = PerlinNoise.create(XoroshiroRandomSource(9001L), listOf(0, 1, 2, 3, 4)) +val CAP_THETA: Float = 18f + /** * Draw a sequence of linePoints spanning the given points. * @@ -77,38 +79,84 @@ fun drawLineSeq( val tess = Tesselator.getInstance() val buf = tess.builder - // We use one single TRIANGLE_STRIP - // in order to connect adjacent segments together and not get the weird hinge effect. - // There's still some artifacting but this is passable, at least. - buf.begin(VertexFormat.Mode.TRIANGLE_STRIP, DefaultVertexFormat.POSITION_COLOR) - val n = points.size + val joinAngles = FloatArray(n) + val joinOffsets = FloatArray(n) + for (i in 2..n-1) { + val p0 = points[i - 2]; + val p1 = points[i - 1]; + val p2 = points[i]; + val prev = p1.add(p0.negated()) + val next = p2.add(p1.negated()) + val angle = Mth.atan2((prev.x * next.y - prev.y * next.x).toDouble(), (prev.x * next.x + prev.y * next.y).toDouble()).toFloat() + joinAngles[i - 1] = angle + val clamp = Math.min(prev.length(), next.length()) / (width * 0.5f); + joinOffsets[i - 1] = Mth.clamp(Mth.sin(angle) / (1 + Mth.cos(angle)), -clamp, clamp) + } + + fun vertex(color: BlockPos, pos: Vec2) = buf.vertex(mat, pos.x, pos.y, z).color(color.x, color.y, color.z, a).endVertex() for ((i, pair) in points.zipWithNext().withIndex()) { val (p1, p2) = pair // https://github.com/not-fl3/macroquad/blob/master/src/shapes.rs#L163 // GuiComponent::innerFill line 52 // fedor have useful variable names challenge (99% can't beat) - val dx = p2.x - p1.x - val dy = p2.y - p1.y - // normal x and y, presumably? - val nx = -dy - val ny = dx - // thickness? - val tlen = Mth.sqrt(nx * nx + ny * ny) / (width * 0.5f) - val tx = nx / tlen - val ty = ny / tlen + val tangent = p2.add(p1.negated()).normalized().scale(width * 0.5f) + val normal = Vec2(-tangent.y, tangent.x) fun color(time: Float): BlockPos = BlockPos(Mth.lerp(time, r1, r2).toInt(), Mth.lerp(time, g1, g2).toInt(), Mth.lerp(time, b1, b2).toInt()) val color1 = color(i.toFloat() / n) val color2 = color((i + 1f) / n) - buf.vertex(mat, p1.x + tx, p1.y + ty, z).color(color1.x, color1.y, color1.z, a).endVertex() - buf.vertex(mat, p1.x - tx, p1.y - ty, z).color(color1.x, color1.y, color1.z, a).endVertex() - buf.vertex(mat, p2.x + tx, p2.y + ty, z).color(color2.x, color2.y, color2.z, a).endVertex() - buf.vertex(mat, p2.x - tx, p2.y - ty, z).color(color2.x, color2.y, color2.z, a).endVertex() + val jlow = joinOffsets[i] + val jhigh = joinOffsets[i + 1] + buf.begin(VertexFormat.Mode.TRIANGLE_FAN, DefaultVertexFormat.POSITION_COLOR) + vertex(color1, p1.add(tangent.scale(Math.max(0f, jlow))).add(normal)) + vertex(color1, p1) + vertex(color1, p1.add(tangent.scale(Math.max(0f, -jlow))).add(normal.negated())) + vertex(color2, p2.add(tangent.scale(Math.max(0f, -jhigh)).negated()).add(normal.negated())) + vertex(color2, p2) + vertex(color2, p2.add(tangent.scale(Math.max(0f, jhigh)).negated()).add(normal)) + tess.end() + + if (i > 0) { + val sangle = joinAngles[i] + val angle = Math.abs(sangle) + val rnormal = normal.negated() + val joinSteps = Mth.ceil(angle * 180 / (CAP_THETA * Mth.PI)) + if (joinSteps < 1) { + continue + } + buf.begin(VertexFormat.Mode.TRIANGLE_FAN, DefaultVertexFormat.POSITION_COLOR) + buf.vertex(mat, p1.x, p1.y, z).color(color1.x, color1.y, color1.z, a).endVertex() + if (sangle < 0) { + for (j in 0..joinSteps) { + val fan = rotate(rnormal, -sangle * (j.toFloat() / joinSteps)) + buf.vertex(mat, p1.x - fan.x, p1.y - fan.y, z).color(color1.x, color1.y, color1.z, a).endVertex() + } + } else { + for (j in joinSteps downTo 0) { + val fan = rotate(normal, -sangle * (j.toFloat() / joinSteps)) + buf.vertex(mat, p1.x - fan.x, p1.y - fan.y, z).color(color1.x, color1.y, color1.z, a).endVertex() + } + } + tess.end() + } } - tess.end() + fun drawCaps(color: BlockPos, point: Vec2, prev: Vec2) { + val tangent = point.add(prev.negated()).normalized().scale(0.5f * width) + val normal = Vec2(-tangent.y, tangent.x) + val joinSteps = Mth.ceil(180f / CAP_THETA) + buf.begin(VertexFormat.Mode.TRIANGLE_FAN, DefaultVertexFormat.POSITION_COLOR) + vertex(color, point) + for (j in joinSteps downTo 0) { + val fan = rotate(normal, -Mth.PI * (j.toFloat() / joinSteps)) + buf.vertex(mat, point.x + fan.x, point.y + fan.y, z).color(color.x, color.y, color.z, a).endVertex() + } + tess.end() + } + drawCaps(BlockPos(r1.toInt(), g1.toInt(), b1.toInt()), points[0], points[1]) + drawCaps(BlockPos(r2.toInt(), g2.toInt(), b2.toInt()), points[n - 1], points[n - 2]) if (animTime != null) { val pointCircuit = @@ -137,6 +185,12 @@ fun drawLineSeq( } } +fun rotate(vec: Vec2, theta: Float): Vec2 { + val cos = Mth.cos(theta) + val sin = Mth.sin(theta) + return Vec2(vec.x * cos - vec.y * sin, vec.y * cos + vec.x * sin) +} + /** * * Draw a hex pattern from the given list of non-zappy points (as in, do the *style* of drawing it, * * you have to do the conversion yourself.)