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Diffstat (limited to 'src/libjin/math/matrix.cpp')
| -rw-r--r-- | src/libjin/math/matrix.cpp | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/src/libjin/math/matrix.cpp b/src/libjin/math/matrix.cpp new file mode 100644 index 0000000..97e9178 --- /dev/null +++ b/src/libjin/math/matrix.cpp @@ -0,0 +1,177 @@ +#include "Matrix.h" + +#include <cstring> // memcpy +#include <cmath> + +namespace jin +{ +namespace math +{ + + // | e0 e4 e8 e12 | + // | e1 e5 e9 e13 | + // | e2 e6 e10 e14 | + // | e3 e7 e11 e15 | + + Matrix::Matrix() + { + setIdentity(); + } + + Matrix::~Matrix() + { + } + + // | e0 e4 e8 e12 | + // | e1 e5 e9 e13 | + // | e2 e6 e10 e14 | + // | e3 e7 e11 e15 | + // | e0 e4 e8 e12 | + // | e1 e5 e9 e13 | + // | e2 e6 e10 e14 | + // | e3 e7 e11 e15 | + + Matrix Matrix::operator * (const Matrix & m) const + { + Matrix t; + + t.e[0] = (e[0] * m.e[0]) + (e[4] * m.e[1]) + (e[8] * m.e[2]) + (e[12] * m.e[3]); + t.e[4] = (e[0] * m.e[4]) + (e[4] * m.e[5]) + (e[8] * m.e[6]) + (e[12] * m.e[7]); + t.e[8] = (e[0] * m.e[8]) + (e[4] * m.e[9]) + (e[8] * m.e[10]) + (e[12] * m.e[11]); + t.e[12] = (e[0] * m.e[12]) + (e[4] * m.e[13]) + (e[8] * m.e[14]) + (e[12] * m.e[15]); + + t.e[1] = (e[1] * m.e[0]) + (e[5] * m.e[1]) + (e[9] * m.e[2]) + (e[13] * m.e[3]); + t.e[5] = (e[1] * m.e[4]) + (e[5] * m.e[5]) + (e[9] * m.e[6]) + (e[13] * m.e[7]); + t.e[9] = (e[1] * m.e[8]) + (e[5] * m.e[9]) + (e[9] * m.e[10]) + (e[13] * m.e[11]); + t.e[13] = (e[1] * m.e[12]) + (e[5] * m.e[13]) + (e[9] * m.e[14]) + (e[13] * m.e[15]); + + t.e[2] = (e[2] * m.e[0]) + (e[6] * m.e[1]) + (e[10] * m.e[2]) + (e[14] * m.e[3]); + t.e[6] = (e[2] * m.e[4]) + (e[6] * m.e[5]) + (e[10] * m.e[6]) + (e[14] * m.e[7]); + t.e[10] = (e[2] * m.e[8]) + (e[6] * m.e[9]) + (e[10] * m.e[10]) + (e[14] * m.e[11]); + t.e[14] = (e[2] * m.e[12]) + (e[6] * m.e[13]) + (e[10] * m.e[14]) + (e[14] * m.e[15]); + + t.e[3] = (e[3] * m.e[0]) + (e[7] * m.e[1]) + (e[11] * m.e[2]) + (e[15] * m.e[3]); + t.e[7] = (e[3] * m.e[4]) + (e[7] * m.e[5]) + (e[11] * m.e[6]) + (e[15] * m.e[7]); + t.e[11] = (e[3] * m.e[8]) + (e[7] * m.e[9]) + (e[11] * m.e[10]) + (e[15] * m.e[11]); + t.e[15] = (e[3] * m.e[12]) + (e[7] * m.e[13]) + (e[11] * m.e[14]) + (e[15] * m.e[15]); + + return t; + } + + void Matrix::operator *= (const Matrix & m) + { + Matrix t = (*this) * m; + memcpy((void*)this->e, (void*)t.e, sizeof(float) * 16); + } + + const float * Matrix::getElements() const + { + return e; + } + + void Matrix::setIdentity() + { + memset(e, 0, sizeof(float) * 16); + e[0] = e[5] = e[10] = e[15] = 1; + } + + void Matrix::setTranslation(float x, float y) + { + setIdentity(); + e[12] = x; + e[13] = y; + } + + void Matrix::setRotation(float rad) + { + setIdentity(); + float c = cos(rad), s = sin(rad); + e[0] = c; e[4] = -s; + e[1] = s; e[5] = c; + } + + void Matrix::setScale(float sx, float sy) + { + setIdentity(); + e[0] = sx; + e[5] = sy; + } + + void Matrix::setShear(float kx, float ky) + { + setIdentity(); + e[1] = ky; + e[4] = kx; + } + + void Matrix::setTransformation(float x, float y, float angle, float sx, float sy, float ox, float oy) + { + memset(e, 0, sizeof(float) * 16); // zero out matrix + float c = cos(angle), s = sin(angle); + // matrix multiplication carried out on paper: + // |1 x| |c -s | |sx | |1 -ox| + // | 1 y| |s c | | sy | | 1 -oy| + // | 1 | | 1 | | 1 | | 1 | + // | 1| | 1| | 1| | 1 | + // move rotate scale origin + e[10] = e[15] = 1.0f; + e[0] = c * sx ; // = a + e[1] = s * sx ; // = b + e[4] = - s * sy; // = c + e[5] = c * sy; // = d + e[12] = x - ox * e[0] - oy * e[4]; + e[13] = y - ox * e[1] - oy * e[5]; + } + + void Matrix::translate(float x, float y) + { + Matrix t; + t.setTranslation(x, y); + this->operator *=(t); + } + + void Matrix::rotate(float rad) + { + Matrix t; + t.setRotation(rad); + this->operator *=(t); + } + + void Matrix::scale(float sx, float sy) + { + Matrix t; + t.setScale(sx, sy); + this->operator *=(t); + } + + void Matrix::shear(float kx, float ky) + { + Matrix t; + t.setShear(kx, ky); + this->operator *=(t); + } + + // | x | + // | y | + // | 0 | + // | 1 | + // | e0 e4 e8 e12 | + // | e1 e5 e9 e13 | + // | e2 e6 e10 e14 | + // | e3 e7 e11 e15 | + + void Matrix::transform(vertex * dst, const vertex * src, int size) const + { + for (int i = 0; i<size; ++i) + { + // Store in temp variables in case src = dst + float x = (e[0] * src[i].x) + (e[4] * src[i].y) + (0) + (e[12]); + float y = (e[1] * src[i].x) + (e[5] * src[i].y) + (0) + (e[13]); + + dst[i].x = x; + dst[i].y = y; + } + } + +} +}
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