diff options
Diffstat (limited to 'themes/src')
| -rw-r--r-- | themes/src/Snowflake.cpp | 61 | ||||
| -rw-r--r-- | themes/src/Snowflake.h | 15 |
2 files changed, 52 insertions, 24 deletions
diff --git a/themes/src/Snowflake.cpp b/themes/src/Snowflake.cpp index 06e04ad..1eb6b74 100644 --- a/themes/src/Snowflake.cpp +++ b/themes/src/Snowflake.cpp @@ -5,6 +5,29 @@ #include <cstdio> const Vector4 snowColor = Vector4(1.0, 0.98, 0.98, 1); +const Vector2 NUM_ARMS_RANGE = Vector2(6.f, 8.f); +const Vector2 RADIUS_RANGE = Vector2(8.f, 32.f); +const Vector2 VELOCITY_RANGE_X = Vector2(-10.f, 10.f); +const Vector2 VELOCITY_RANGE_Y = Vector2(-100.f, -85.f); +const Vector2 ROTATION_VELOCITY_RANGE = Vector2(-PI / 8.f, PI / 8.f); +const Vector2 WIND_VELOCITY_RANGE_X = Vector2(-3.f, 3.f); +const Vector2 WIND_VELOCITY_RANGE_Y = Vector2(3.f, 10.f); +const f32 GRAVITY = 5.f; + +inline void generateSnowflakeArm(f32 width, f32 height, f32 angle, matte::List<Vertex2D>* vertices, Mat4x4 transform = Mat4x4()) { + f32 halfWidth = width / 2.f; + Vector2 leftStart = transform * Vector2(-halfWidth, 0).rotate(angle); + Vector2 leftEnd = transform * Vector2(-halfWidth, height).rotate(angle); + Vector2 rightStart = transform * Vector2(halfWidth, 0).rotate(angle); + Vector2 rightEnd = transform * Vector2(halfWidth, height).rotate(angle); + + 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() }); +} /** Fills in the vertices array vertices that represent a snowflake shape. The snowflake shape consists @@ -25,30 +48,32 @@ inline void generateSnowflakeShape(matte::List<Vertex2D>* vertices, i32 numArms, 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() }); + generateSnowflakeArm(armWidthRatio * radius, radius, armAngle, vertices); + f32 armLeftAngle = DEG_TO_RAD(60.f); + f32 armRightAngle = DEG_TO_RAD(-60.f); + + const i32 NUM_SUB_ARMS = 4; + for (i32 subArmIndex = 0; subArmIndex < NUM_SUB_ARMS; subArmIndex++) { + f32 height = (radius / static_cast<f32>(subArmIndex)); + f32 width = (armWidthRatio / (subArmIndex + 1)) * height; + f32 transY = (radius / (NUM_SUB_ARMS + 1)) * (subArmIndex + 1); + Vector2 translation = Vector2(0, transY).rotate(armAngle); + generateSnowflakeArm(width, height, armAngle, vertices, Mat4x4().translateByVec2(translation).rotate2D(armLeftAngle)); + generateSnowflakeArm(width, height, armAngle, vertices, Mat4x4().translateByVec2(translation).rotate2D(armRightAngle)); + } } } inline void initFlake(SnowflakeParticleRenderer* renderer, SnowflakeUpdateData* ud) { ud->vtxIdx = renderer->vertices.numElements; generateSnowflakeShape(&renderer->vertices, - 6, - randomFloatBetween(8.f, 16.f)); + randomFloatBetween(NUM_ARMS_RANGE.x, NUM_ARMS_RANGE.y), + randomFloatBetween(RADIUS_RANGE.x, RADIUS_RANGE.y)); ud->numVertices = renderer->vertices.numElements - ud->vtxIdx; - ud->velocity = Vector2(randomFloatBetween(-10, 10), randomFloatBetween(-100, -85)); + ud->velocity = Vector2(randomFloatBetween(VELOCITY_RANGE_X.x, VELOCITY_RANGE_X.y), randomFloatBetween(VELOCITY_RANGE_Y.x, VELOCITY_RANGE_Y.y)); ud->position = Vector2(randomFloatBetween(0, renderer->xMax), randomFloatBetween(renderer->yMax, 4 * renderer->yMax)); - ud->rotateVelocity = randomFloatBetween(-PI / 8.f, PI / 8.f); + ud->rotateVelocity = randomFloatBetween(ROTATION_VELOCITY_RANGE.x, ROTATION_VELOCITY_RANGE.y); } void SnowflakeParticleRenderer::load(SnowflakeLoadParameters params, Renderer2d* renderer) { @@ -104,7 +129,8 @@ inline void resetFlake(SnowflakeParticleRenderer* renderer, SnowflakeUpdateData* } inline void updateFlake(SnowflakeParticleRenderer* renderer, SnowflakeUpdateData* ud, i32 s, f32 dtSeconds, bool addWind) { - if (addWind) ud->velocity += renderer->windSpeed; + ud->velocity = ud->velocity + Vector2(0, -(GRAVITY * dtSeconds)); + if (addWind) ud->velocity += renderer->windSpeed; ud->position += ud->velocity * dtSeconds; ud->rotation += ud->rotateVelocity * dtSeconds; @@ -123,7 +149,8 @@ void SnowflakeParticleRenderer::update(f32 dtSeconds) { timeUntilNextWindSeconds -= dtSeconds; if (timeUntilNextWindSeconds < 0) { timeUntilNextWindSeconds = windIntervalSeconds; - windSpeed = Vector2(randomFloatBetween(-10, 10), randomFloatBetween(-10, 0)); + windSpeed = Vector2(randomFloatBetween(WIND_VELOCITY_RANGE_X.x, WIND_VELOCITY_RANGE_X.y), + randomFloatBetween(WIND_VELOCITY_RANGE_Y.x, WIND_VELOCITY_RANGE_Y.y)); addWind = true; } diff --git a/themes/src/Snowflake.h b/themes/src/Snowflake.h index 02673c1..2524483 100644 --- a/themes/src/Snowflake.h +++ b/themes/src/Snowflake.h @@ -1,3 +1,6 @@ +#ifndef SNOWFLAKE_H +#define SNOWFLAKE_H + #include "types.h" #include "mathlib.h" #include "list.h" @@ -6,15 +9,11 @@ struct Renderer2d; struct Vertex2D; struct SnowflakeLoadParameters { - i32 numSnowflakes = 500; - f32 rateOfSnowfall = 0.1f; - Vector2 flakeV0 = { 0, 1 }; - Vector4 snowColor = { 0.8, 0.8, 0.8, 1.0 }; - f32 windIntervalSeconds = 1.5; + i32 numSnowflakes = 480; + f32 windIntervalSeconds = 1.5f; }; struct SnowflakeUpdateData { - Vector2 v0; Vector2 velocity; Vector2 position; f32 rotateVelocity = 0.f; @@ -30,8 +29,8 @@ struct SnowflakeParticleRenderer { f32 windIntervalSeconds = 1.5; i32 numSnowflakes = 0; Vector2 windSpeed; - SnowflakeUpdateData* updateData; f32 timeUntilNextWindSeconds = 0; + SnowflakeUpdateData* updateData; u32 vao; u32 vbo; @@ -43,3 +42,5 @@ struct SnowflakeParticleRenderer { void render(Renderer2d* renderer); void unload(); }; + +#endif |