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authormattkae <mattkae@protonmail.com>2023-01-02 10:10:48 -0500
committermattkae <mattkae@protonmail.com>2023-01-02 10:10:48 -0500
commitbe692c3f5b7d9fb537262fc3336eca1607167779 (patch)
treef8fa713e77581179c9a7f0c125aafb1822cc5443 /themes/src
parent66e768c89bf91fb05a93ecd2519898eb70b7b8d4 (diff)
Snowflakes are looking reasonable once again
Diffstat (limited to 'themes/src')
-rw-r--r--themes/src/Snowflake.cpp54
1 files changed, 29 insertions, 25 deletions
diff --git a/themes/src/Snowflake.cpp b/themes/src/Snowflake.cpp
index 9941a5b..06e04ad 100644
--- a/themes/src/Snowflake.cpp
+++ b/themes/src/Snowflake.cpp
@@ -6,44 +6,48 @@
const Vector4 snowColor = Vector4(1.0, 0.98, 0.98, 1);
-inline void generateSnowflakeShape(matte::List<Vertex2D>* vertices, i32 numArms, f32 outerRadius, f32 innerRadius) {
- outerRadius = outerRadius + innerRadius;
- f32 dx = ((2 * PI) / numArms) / 3.0;
- for (i32 centerIdx = 0; centerIdx < (3 * numArms); centerIdx+=3) {
- f32 degreeStart = dx * centerIdx;
- f32 degreeEnd = dx * (centerIdx + 1);
-
- f32 cosStart = cosf(degreeStart);
- f32 cosEnd = cosf(degreeEnd);
-
- f32 sinStart = sinf(degreeStart);
- f32 sinEnd = sinf(degreeEnd);
-
- Vector2 leftEnd = Vector2(outerRadius * cosStart, outerRadius * sinStart);
- Vector2 rightEnd = Vector2(outerRadius * cosEnd, outerRadius * sinEnd);
- Vector2 diff = (rightEnd - leftEnd) / 2.0;
- Vector2 leftStart = Vector2(-diff.x, -diff.y) + Vector2(innerRadius * cosStart, innerRadius * sinStart);
- Vector2 rightStart = diff + Vector2(innerRadius * cosEnd, innerRadius * sinEnd);
-
+/**
+ Fills in the vertices array vertices that represent a snowflake shape. The snowflake shape consists
+ of numArms jutting out of the center radially. The center of the flake is connected. The radius is
+ used to determine the length of the arms. The first third of each arm is barren, after which branches
+ extends on either side of the arm at an angle of about 60 degrees. Each branch can itself have tiny
+ sub branches jutting out of it, but these should be not nearly as large as the regular branches.
+
+ With all of this in mind, we should be able to build a convincing snowflake.
+
+ :param vertices List of vertices to be filled in
+ :param numArms Number of arms radially sticking out of the snowflake
+ :param radius Length of the snowflake arms
+ */
+inline void generateSnowflakeShape(matte::List<Vertex2D>* vertices, i32 numArms, f32 radius, f32 armWidthRatio = 0.08f) {
+ f32 innerRadius = 0;
+ f32 outerRadius = 2 * radius;
+ f32 dx = ((2 * PI) / numArms);
+ for (i32 armIndex = 0; armIndex < numArms; armIndex++) {
+ f32 armAngle = dx * armIndex;
+ Vector2 leftStart = Vector2(-armWidthRatio * radius, 0).rotate(armAngle);
+ Vector2 leftEnd = Vector2(-armWidthRatio * radius, radius).rotate(armAngle);
+ Vector2 rightStart = Vector2(armWidthRatio * radius, 0).rotate(armAngle);
+ Vector2 rightEnd = Vector2(armWidthRatio * radius, radius).rotate(armAngle);
+
vertices->add({ leftStart, snowColor, Mat4x4() });
vertices->add({ leftEnd, snowColor, Mat4x4() });
vertices->add({ rightEnd, snowColor, Mat4x4() });
+ vertices->add({ leftStart, snowColor, Mat4x4() });
vertices->add({ rightEnd, snowColor, Mat4x4() });
vertices->add({ rightStart, snowColor, Mat4x4() });
- vertices->add({ leftStart, snowColor, Mat4x4() });
- }
+ }
}
inline void initFlake(SnowflakeParticleRenderer* renderer, SnowflakeUpdateData* ud) {
ud->vtxIdx = renderer->vertices.numElements;
generateSnowflakeShape(&renderer->vertices,
- randomIntBetween(4, 12),
- randomFloatBetween(4.f, 12.f),
- randomFloatBetween(4.f, 12.f));
+ 6,
+ randomFloatBetween(8.f, 16.f));
ud->numVertices = renderer->vertices.numElements - ud->vtxIdx;
ud->velocity = Vector2(randomFloatBetween(-10, 10), randomFloatBetween(-100, -85));
- ud->position = Vector2(randomFloatBetween(0, renderer->xMax), randomFloatBetween(renderer->yMax, 3 * renderer->yMax));
+ ud->position = Vector2(randomFloatBetween(0, renderer->xMax), randomFloatBetween(renderer->yMax, 4 * renderer->yMax));
ud->rotateVelocity = randomFloatBetween(-PI / 8.f, PI / 8.f);
}