Function Particles_BreakBlockEffect

src/Particle.c:327–406

}

void Particles_BreakBlockEffect(IVec3 coords, BlockID old, BlockID now) {
	struct TerrainParticle* p;
	TextureLoc loc;
	int texIndex;
	TextureRec baseRec, rec;
	Vec3 origin, minBB, maxBB;

	/* texture UV variables */
	float uScale, vScale, maxU2, maxV2;
	int minX, minZ, maxX, maxZ;
	int minU, minV, maxU, maxV;
	int maxUsedU, maxUsedV;
	
	/* per-particle variables */
	float cellX, cellY, cellZ;
	Vec3 cell;
	int x, y, z, type;

	if (now != BLOCK_AIR || Blocks.Draw[old] == DRAW_GAS) return;
	IVec3_ToVec3(&origin, &coords);
	loc = Block_Tex(old, FACE_XMIN);
	
	baseRec = Atlas1D_TexRec(loc, 1, &texIndex);
	uScale  = (1.0f/16.0f); vScale = (1.0f/16.0f) * Atlas1D.InvTileSize;

	minBB = Blocks.MinBB[old];    maxBB = Blocks.MaxBB[old];
	minX  = (int)(minBB.x * 16); maxX  = (int)(maxBB.x * 16);
	minZ  = (int)(minBB.z * 16); maxZ  = (int)(maxBB.z * 16);

	minU = min(minX, minZ); minV = (int)(16 - maxBB.y * 16);
	maxU = min(maxX, maxZ); maxV = (int)(16 - minBB.y * 16);
	/* This way we can avoid creating particles which outside the bounds and need to be clamped */
	maxUsedU = maxU; maxUsedV = maxV;
	if (minU < 12 && maxU > 12) maxUsedU = 12;
	if (minV < 12 && maxV > 12) maxUsedV = 12;

	#define GRID_SIZE 4
	/* gridOffset gives the centre of the cell on a grid */
	#define CELL_CENTRE ((1.0f / GRID_SIZE) * 0.5f)

	maxU2 = baseRec.u1 + maxU * uScale;
	maxV2 = baseRec.v1 + maxV * vScale;
	for (x = 0; x < GRID_SIZE; x++) {
		for (y = 0; y < GRID_SIZE; y++) {
			for (z = 0; z < GRID_SIZE; z++) {

				cellX = (float)x / GRID_SIZE; cellY = (float)y / GRID_SIZE; cellZ = (float)z / GRID_SIZE;
				cell  = Vec3_Create3(CELL_CENTRE + cellX, CELL_CENTRE / 2 + cellY, CELL_CENTRE + cellZ);
				if (cell.x < minBB.x || cell.x > maxBB.x || cell.y < minBB.y
					|| cell.y > maxBB.y || cell.z < minBB.z || cell.z > maxBB.z) continue;

				if (terrain_count == PARTICLES_MAX) Terrain_RemoveAt(0);
				p = &terrain_particles[terrain_count++];

				/* centre random offset around [-0.2, 0.2] */
				p->base.velocity.x = CELL_CENTRE + (cellX - 0.5f) + (Random_Float(&rnd) * 0.4f - 0.2f);
				p->base.velocity.y = CELL_CENTRE + (cellY - 0.0f) + (Random_Float(&rnd) * 0.4f - 0.2f);
				p->base.velocity.z = CELL_CENTRE + (cellZ - 0.5f) + (Random_Float(&rnd) * 0.4f - 0.2f);