顶点数据的生成
1 bool YfBuildConeVertices 2 ( 3 Yreal radius, 4 Yreal height, 5 Yuint slices, 6 YeOriginPose originPose, 7 Yuint vertexStriding, 8 Yuint vertexPos, 9 void* pVerticesBuffer 10 ) 11 { 12 if (slices < 2 || !pVerticesBuffer) 13 { 14 return false; 15 } 16 17 Yuint numVertices = slices + 2; 18 19 // 顶点赋值 20 char* vertexPtr = (char*)pVerticesBuffer + vertexPos; 21 YsVector3* curVertexPtr = NULL; 22 Yuint nOffset = 0; 23 24 Yreal originOffsetY = 0.0f; 25 if (originPose == YE_ORIGIN_POSE_TOP) 26 { 27 originOffsetY = -height; 28 } 29 else if (originPose == YE_ORIGIN_POSE_CENTER) 30 { 31 originOffsetY = -height * 0.5f; 32 } 33 34 // 锥尖顶点赋值 35 { 36 nOffset = 0; 37 curVertexPtr = (YsVector3*)(vertexPtr + nOffset); 38 curVertexPtr->x = 0.0f; 39 curVertexPtr->y = height + originOffsetY; 40 curVertexPtr->z = 0.0f; 41 } 42 43 // 锥底顶点赋值 44 { 45 nOffset = (numVertices - 1) * vertexStriding; 46 curVertexPtr = (YsVector3*)(vertexPtr + nOffset); 47 curVertexPtr->x = 0.0f; 48 curVertexPtr->y = originOffsetY; 49 curVertexPtr->z = 0.0f; 50 } 51 52 Yreal angleXZ; 53 Yreal posX, posZ; 54 for (Yuint i = 0; i < slices; i++) 55 { 56 angleXZ = YD_REAL_TWAIN_PI * i / slices; 57 posX = yf_sin(angleXZ); 58 posZ = yf_cos(angleXZ); 59 nOffset = (i + 1) * vertexStriding; 60 61 curVertexPtr = (YsVector3*)(vertexPtr + nOffset); 62 curVertexPtr->x = radius * posX; 63 curVertexPtr->y = originOffsetY; 64 curVertexPtr->z = radius * posZ; 65 } 66 67 return true; 68 }
三角形索引数据的生成
1 bool YfBuildConeTriIndices 2 ( 3 Yuint slices, 4 YeIndexType indexType, 5 Yuint indexStriding, 6 Yuint indexPos, 7 void* pTriIndicesBuffer 8 ) 9 { 10 if (slices < 2 || !pTriIndicesBuffer) 11 { 12 return false; 13 } 14 15 Yuint numVertices = slices + 2; 16 Yuint numTriangles = slices * 2; 17 if (indexType == YE_INDEX_16_BIT && 18 numVertices > YD_MAX_UNSIGNED_INT16) 19 { 20 return false; 21 } 22 23 // 索引赋值 24 char* indexPtr = (char*)pTriIndicesBuffer + indexPos; 25 Yuint nOffset = 0; 26 if (indexType == YE_INDEX_16_BIT) 27 { 28 YsTriIndex16* triIndexPtr = NULL; 29 for (Yuint i= 0; i < slices; i++) 30 { 31 nOffset = (i * 2) * indexStriding; 32 triIndexPtr = (YsTriIndex16*)(indexPtr + nOffset); 33 triIndexPtr->index0 = 0; 34 triIndexPtr->index1 = 1 + i; 35 triIndexPtr->index2 = 1 + (i + 1)%slices; 36 37 nOffset += indexStriding; 38 triIndexPtr = (YsTriIndex16*)(indexPtr + nOffset); 39 triIndexPtr->index0 = numVertices - 1; 40 triIndexPtr->index1 = 1 + (i + 1)%slices; 41 triIndexPtr->index2 = 1 + i; 42 } 43 } 44 else 45 { 46 YsTriIndex32* triIndexPtr = NULL; 47 for (Yuint i= 0; i < slices; i++) 48 { 49 nOffset = (i * 2) * indexStriding; 50 triIndexPtr = (YsTriIndex32*)(indexPtr + nOffset); 51 triIndexPtr->index0 = 0; 52 triIndexPtr->index1 = 1 + i; 53 triIndexPtr->index2 = 1 + (i + 1)%slices; 54 55 nOffset += indexStriding; 56 triIndexPtr = (YsTriIndex32*)(indexPtr + nOffset); 57 triIndexPtr->index0 = numVertices - 1; 58 triIndexPtr->index1 = 1 + (i + 1)%slices; 59 triIndexPtr->index2 = 1 + i; 60 } 61 } 62 63 return true; 64 }
线框索引数据的生成
1 bool YfBuildConeWireIndices 2 ( 3 Yuint slices, 4 YeIndexType indexType, 5 Yuint indexStriding, 6 Yuint indexPos, 7 void* pWireIndicesBuffer 8 ) 9 { 10 if (slices < 2 || !pWireIndicesBuffer) 11 { 12 return false; 13 } 14 15 Yuint numVertices = slices + 2; 16 Yuint numLines = slices * 2; 17 if (indexType == YE_INDEX_16_BIT && 18 numVertices > YD_MAX_UNSIGNED_INT16) 19 { 20 return false; 21 } 22 23 // 索引赋值 24 char* indexPtr = (char*)pWireIndicesBuffer + indexPos; 25 Yuint nOffset = 0; 26 if (indexType == YE_INDEX_16_BIT) 27 { 28 YsLineIndex16* lineIndexPtr = NULL; 29 for (Yuint i= 0; i < slices; i++) 30 { 31 nOffset = (i * 2) * indexStriding; 32 lineIndexPtr = (YsLineIndex16*)(indexPtr + nOffset); 33 lineIndexPtr->index0 = 0; 34 lineIndexPtr->index1 = 1 + i; 35 36 nOffset += indexStriding; 37 lineIndexPtr = (YsLineIndex16*)(indexPtr + nOffset); 38 lineIndexPtr->index0 = 1 + i; 39 lineIndexPtr->index1 = 1 + (i + 1)%slices; 40 } 41 } 42 else 43 { 44 YsLineIndex32* lineIndexPtr = NULL; 45 for (Yuint i= 0; i < slices; i++) 46 { 47 nOffset = (i * 2) * indexStriding; 48 lineIndexPtr = (YsLineIndex32*)(indexPtr + nOffset); 49 lineIndexPtr->index0 = 0; 50 lineIndexPtr->index1 = 1 + i; 51 52 nOffset += indexStriding; 53 lineIndexPtr = (YsLineIndex32*)(indexPtr + nOffset); 54 lineIndexPtr->index0 = 1 + i; 55 lineIndexPtr->index1 = 1 + (i + 1)%slices; 56 } 57 } 58 59 return true; 60 }