作者：小桃爱学PHP | 来源：互联网 | 2023-05-17 14:12
顶点数据的生成
1 bool YfBuildRingVertices
2 (
3 Yreal radius,
4 Yreal assistRadius,
5 Yreal height,
6 Yuint slices,
7 Yuint stacks,
8 YeOriginPose originPose,
9 Yuint vertexStriding,
10 Yuint vertexPos,
11 void* pVerticesBuffer
12 )
13 {
14 if (slices <2 || stacks <3 || !pVerticesBuffer)
15 {
16 return false;
17 }
18
19 Yuint numVertices = slices * stacks;
20 Yuint numTriangles = slices * stacks * 2;
21
22 char* vertexPtr = (char*)pVerticesBuffer + vertexPos;
23 YsVector3* curVertexPtr = NULL;
24 Yuint nOffset = 0;
25
26 Yreal halfHeight = height * 0.5f;
27 Yreal originOffsetY = 0.0f;
28 if (originPose == YE_ORIGIN_POSE_TOP)
29 {
30 originOffsetY = -halfHeight;
31 }
32 else if (originPose == YE_ORIGIN_POSE_BOTTOM)
33 {
34 originOffsetY = halfHeight;
35 }
36
37 Yreal angle, s, c;
38 YsVector3* initVerticesPtr = new YsVector3[slices + 1];
39 for (Yuint j = 0; j )
40 {
41 angle = YD_REAL_TWAIN_PI * j / slices;
42 s = yf_sin(angle);
43 c = yf_cos(angle);
44 initVerticesPtr[j].x = radius + assistRadius*s;
45 initVerticesPtr[j].y = halfHeight*c + originOffsetY;
46 initVerticesPtr[j].z = 0.0f;
47 }
48
49 for (Yuint i = 0; i )
50 {
51 angle = YD_REAL_TWAIN_PI * i / stacks;
52 s = yf_sin(angle);
53 c = yf_cos(angle);
54
55 for (Yuint j = 0; j )
56 {
57 nOffset = (i * slices + j) * vertexStriding;
58 curVertexPtr = (YsVector3*)(vertexPtr + nOffset);
59 curVertexPtr->x = initVerticesPtr[j].x * s;
60 curVertexPtr->y = initVerticesPtr[j].y;
61 curVertexPtr->z = initVerticesPtr[j].x * c;
62 }
63 }
64
65 YD_SAFE_DELETE_ARRAY(initVerticesPtr);
66
67 return true;
68 }
三角形索引数据的生成
1 bool YfBuildRingTriIndices
2 (
3 Yuint slices,
4 Yuint stacks,
5 YeIndexType indexType,
6 Yuint indexStriding,
7 Yuint indexPos,
8 void* pTriIndicesBuffer
9 )
10 {
11 if (slices <2 || stacks <3 || !pTriIndicesBuffer)
12 {
13 return false;
14 }
15
16 Yuint numVertices = slices * stacks;
17 Yuint numTriangles = slices * stacks * 2;
18 if (indexType == YE_INDEX_16_BIT &&
19 numVertices > YD_MAX_UNSIGNED_INT16)
20 {
21 return false;
22 }
23
24 // 索引赋值
25 char* indexPtr = (char*)pTriIndicesBuffer + indexPos;
26 Yuint nOffset = 0;
27 if (indexType == YE_INDEX_16_BIT)
28 {
29 YsTriIndex16* triIndexPtr = NULL;
30 for (Yuint i = 0; i )
31 {
32 for (Yuint j = 0; j )
33 {
34 nOffset = (i*slices + j)*2 * indexStriding;
35 triIndexPtr = (YsTriIndex16*)(indexPtr + nOffset);
36 triIndexPtr->index0 = slices * i + j;
37 triIndexPtr->index1 = slices * i + (j + 1)%slices;
38 triIndexPtr->index2 = slices * ((i + 1) % stacks) + j;
39
40 nOffset += indexStriding;
41 triIndexPtr = (YsTriIndex16*)(indexPtr + nOffset);
42 triIndexPtr->index0 = slices * i + (j + 1)%slices;
43 triIndexPtr->index1 = slices * ((i + 1) % stacks) + (j + 1)%slices;
44 triIndexPtr->index2 = slices * ((i + 1) % stacks) + j;
45 }
46 }
47 }
48 else
49 {
50 YsTriIndex32* triIndexPtr = NULL;
51 for (Yuint i = 0; i )
52 {
53 for (Yuint j = 0; j )
54 {
55 nOffset = (i*slices + j)*2 * indexStriding;
56 triIndexPtr = (YsTriIndex32*)(indexPtr + nOffset);
57 triIndexPtr->index0 = slices * i + j;
58 triIndexPtr->index1 = slices * i + (j + 1)%slices;
59 triIndexPtr->index2 = slices * ((i + 1) % stacks) + j;
60
61 nOffset += indexStriding;
62 triIndexPtr = (YsTriIndex32*)(indexPtr + nOffset);
63 triIndexPtr->index0 = slices * i + (j + 1)%slices;
64 triIndexPtr->index1 = slices * ((i + 1) % stacks) + (j + 1)%slices;
65 triIndexPtr->index2 = slices * ((i + 1) % stacks) + j;
66 }
67 }
68 }
69
70 return true;
71 }
线框索引数据的生成
1 bool YfBuildRingWireIndices
2 (
3 Yuint slices,
4 Yuint stacks,
5 YeIndexType indexType,
6 Yuint indexStriding,
7 Yuint indexPos,
8 void* pWireIndicesBuffer
9 )
10 {
11 if (slices <2 || !pWireIndicesBuffer)
12 {
13 return false;
14 }
15
16 Yuint numVertices = slices * stacks;
17 Yuint numLines = slices * stacks * 2;
18 if (indexType == YE_INDEX_16_BIT &&
19 numVertices > YD_MAX_UNSIGNED_INT16)
20 {
21 return false;
22 }
23
24 // 索引赋值
25 char* indexPtr = (char*)pWireIndicesBuffer + indexPos;
26 Yuint nOffset = 0;
27 if (indexType == YE_INDEX_16_BIT)
28 {
29 YsLineIndex16* lineIndexPtr = NULL;
30 for (Yuint i = 0; i )
31 {
32 for (Yuint j = 0; j )
33 {
34 nOffset = (i*slices + j) * 2 * indexStriding;
35 lineIndexPtr = (YsLineIndex16*)(indexPtr + nOffset);
36 lineIndexPtr->index0 = slices * i + j;
37 lineIndexPtr->index1 = slices * i + (j + 1)%slices;
38
39 nOffset += indexStriding;
40 lineIndexPtr = (YsLineIndex16*)(indexPtr + nOffset);
41 lineIndexPtr->index0 = slices * i + j;
42 lineIndexPtr->index1 = slices * ((i + 1) % stacks) + j;
43 }
44 }
45 }
46 else
47 {
48 YsLineIndex32* lineIndexPtr = NULL;
49 for (Yuint i = 0; i )
50 {
51 for (Yuint j = 0; j )
52 {
53 nOffset = (i*slices + j) * 2 * indexStriding;
54 lineIndexPtr = (YsLineIndex32*)(indexPtr + nOffset);
55 lineIndexPtr->index0 = slices * i + j;
56 lineIndexPtr->index1 = slices * i + (j + 1)%slices;
57
58 nOffset += indexStriding;
59 lineIndexPtr = (YsLineIndex32*)(indexPtr + nOffset);
60 lineIndexPtr->index0 = slices * i + j;
61 lineIndexPtr->index1 = slices * ((i + 1) % stacks) + j;
62 }
63 }
64 }
65
66 return true;
67 }
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