OpenGL实现线框地形

// Math3d.c // Implementation of non-inlined functions in the Math3D Library // Richard S. Wright Jr. // These are pretty portable #include <math.h> #include "math3d.h" //////////////////////////////////////////////////////////// // LoadIdentity // For 3x3 and 4x4 float and double matricies. // 3x3 float void m3dLoadIdentity33(M3DMatrix33f m) { // Don't be fooled, this is still column major static M3DMatrix33f identity = { 1.0f, 0.0f, 0.0f , 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 1.0f }; memcpy(m, identity, sizeof(M3DMatrix33f)); } // 3x3 double void m3dLoadIdentity33(M3DMatrix33d m) { // Don't be fooled, this is still column major static M3DMatrix33d identity = { 1.0, 0.0, 0.0 , 0.0, 1.0, 0.0, 0.0, 0.0, 1.0 }; memcpy(m, identity, sizeof(M3DMatrix33d)); } // 4x4 float void m3dLoadIdentity44(M3DMatrix44f m) { // Don't be fooled, this is still column major static M3DMatrix44f identity = { 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f }; memcpy(m, identity, sizeof(M3DMatrix44f)); } // 4x4 double void m3dLoadIdentity44(M3DMatrix44d m) { static M3DMatrix44d identity = { 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0 }; memcpy(m, identity, sizeof(M3DMatrix44d)); } //////////////////////////////////////////////////////////////////////// // Return the square of the distance between two points // Should these be inlined...? float m3dGetDistanceSquared(const M3DVector3f u, const M3DVector3f v) { float x = u[0] - v[0]; x = x*x; float y = u[1] - v[1]; y = y*y; float z = u[2] - v[2]; z = z*z; return (x + y + z); } // Ditto above, but for doubles double m3dGetDistanceSquared(const M3DVector3d u, const M3DVector3d v) { double x = u[0] - v[0]; x = x*x; double y = u[1] - v[1]; y = y*y; double z = u[2] - v[2]; z = z*z; return (x + y + z); } #define A(row,col) a[(col<<2)+row] #define B(row,col) b[(col<<2)+row] #define P(row,col) product[(col<<2)+row] /////////////////////////////////////////////////////////////////////////////// // Multiply two 4x4 matricies void m3dMatrixMultiply44(M3DMatrix44f product, const M3DMatrix44f a, const M3DMatrix44f b ) { for (int i = 0; i < 4; i++) { float ai0=A(i,0), ai1=A(i,1), ai2=A(i,2), ai3=A(i,3); P(i,0) = ai0 * B(0,0) + ai1 * B(1,0) + ai2 * B(2,0) + ai3 * B(3,0); P(i,1) = ai0 * B(0,1) + ai1 * B(1,1) + ai2 * B(2,1) + ai3 * B(3,1); P(i,2) = ai0 * B(0,2) + ai1 * B(1,2) + ai2 * B(2,2) + ai3 * B(3,2); P(i,3) = ai0 * B(0,3) + ai1 * B(1,3) + ai2 * B(2,3) + ai3 * B(3,3); } } // Ditto above, but for doubles void m3dMatrixMultiply(M3DMatrix44d product, const M3DMatrix44d a, const M3DMatrix44d b ) { for (int i = 0; i < 4; i++) { double ai0=A(i,0), ai1=A(i,1), ai2=A(i,2), ai3=A(i,3); P(i,0) = ai0 * B(0,0) + ai1 * B(1,0) + ai2 * B(2,0) + ai3 * B(3,0); P(i,1) = ai0 * B(0,1) + ai1 * B(1,1) + ai2 * B(2,1) + ai3 * B(3,1); P(i,2) = ai0 * B(0,2) + ai1 * B(1,2) + ai2 * B(2,2) + ai3 * B(3,2); P(i,3) = ai0 * B(0,3) + ai1 * B(1,3) + ai2 * B(2,3) + ai3 * B(3,3); } } #undef A #undef B #undef P #define A33(row,col) a[(col*3)+row] #define B33(row,col) b[(col*3)+row] #define P33(row,col) product[(col*3)+row] /////////////////////////////////////////////////////////////////////////////// // Multiply two 3x3 matricies void m3dMatrixMultiply33(M3DMatrix33f product, const M3DMatrix33f a, const M3DMatrix33f b ) { for (int i = 0; i < 3; i++) { float ai0=A33(i,0), ai1=A33(i,1), ai2=A33(i,2); P33(i,0) = ai0 * B33(0,0) + ai1 * B33(1,0) + ai2 * B33(2,0); P33(i,1) = ai0 * B33(0,1) + ai1 * B33(1,1) + ai2 * B33(2,1); P33(i,2) = ai0 * B33(0,2) + ai1 * B33(1,2) + ai2 * B33(2,2); } } // Ditto above, but for doubles void m3dMatrixMultiply44(M3DMatrix33d product, const M3DMatrix33d a, const M3DMatrix33d b ) { for (int i = 0; i < 3; i++) { double ai0=A33(i,0), ai1=A33(i,1), ai2=A33(i,2); P33(i,0) = ai0 * B33(0,0) + ai1 * B33(1,0) + ai2 * B33(2,0); P33(i,1) = ai0 * B33(0,1) + ai1 * B33(1,1) + ai2 * B33(2,1); P33(i,2) = ai0 * B33(0,2) + ai1 * B33(1,2) + ai2 * B33(2,2); } } #undef A33 #undef B33 #undef P33 #define M33(row,col) m[col*3+row] /////////////////////////////////////////////////////////////////////////////// // Creates a 3x3 rotation matrix, takes radians NOT degrees void m3dRotationMatrix33(M3DMatrix33f m, float angle, float x, float y, float z) { float mag, s, c; float xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c; s = float(sin(angle)); c = float(cos(angle)); mag = float(sqrt( x*x + y*y + z*z )); // Identity matrix if (mag == 0.0f) { m3dLoadIdentity33(m); return; } // Rotation matrix is normalized x /= mag; y /= mag; z /= mag; xx = x * x; yy = y * y; zz = z * z; xy = x * y; yz = y * z; zx = z * x; xs = x * s; ys = y * s; zs = z * s; one_c = 1.0f - c; M33(0,0) = (one_c * xx) + c; M33(0,1) = (one_c * xy) - zs; M33(0,2) = (one_c * zx) + ys; M33(1,0) = (one_c * xy) + zs; M33(1,1) = (one_c * yy) + c; M33(1,2) = (one_c * yz) - xs; M33(2,0) = (one_c * zx) - ys; M33(2,1) = (one_c * yz) + xs; M33(2,2) = (one_c * zz) + c; } #undef M33 /////////////////////////////////////////////////////////////////////////////// // Creates a 4x4 rotation matrix, takes radians NOT degrees void m3dRotationMatrix44(M3DMatrix44f m, float angle, float x, float y, float z) { float mag, s, c; float xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c; s = float(sin(angle)); c = float(cos(angle)); mag = float(sqrt( x*x + y*y + z*z )); // Identity matrix if (mag == 0.0f) { m3dLoadIdentity44(m); return; } // Rotation matrix is normalized x /= mag; y /= mag; z /= mag; #define M(row,col) m[col*4+row] xx = x * x; yy = y * y; zz = z * z; xy = x * y; yz = y * z; zx = z * x; xs = x * s; ys = y * s; zs = z * s; one_c = 1.0f - c; M(0,0) = (one_c * xx) + c; M(0,1) = (one_c * xy) - zs; M(0,2) = (one_c * zx) + ys; M(0,3) = 0.0f; M(1,0) = (one_c * xy) + zs; M(1,1) = (one_c * yy) + c; M(1,2) = (one_c * yz) - xs; M(1,3) = 0.0f; M(2,0) = (one_c * zx) - ys; M(2,1) = (one_c * yz) + xs; M(2,2) = (one_c * zz) + c; M(2,3) = 0.0f; M(3,0) = 0.0f; M(3,1) = 0.0f; M(3,2) = 0.0f; M(3,3) = 1.0f; #undef M } /////////////////////////////////////////////////////////////////////////////// // Ditto above, but for doubles void m3dRotationMatrix33(M3DMatrix33d m, double angle, double x, double y, double z) { double mag, s, c; double xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c; s = sin(angle); c = cos(angle); mag = sqrt( x*x + y*y + z*z ); // Identity matrix if (mag == 0.0) { m3dLoadIdentity33(m); return; } // Rotation matrix is normalized x /= mag; y /= mag; z /= mag; #define M(row,col) m[col*3+row] xx = x * x; yy = y * y; zz = z * z; xy = x * y; yz = y * z; zx = z * x; xs = x * s; ys = y * s; zs = z * s; one_c = 1.0 - c; M(0,0) = (one_c * xx) + c; M(0,1) = (one_c * xy) - zs; M(0,2) = (one_c * zx) + ys; M(1,0) = (one_c * xy) + zs; M(1,1) = (one_c * yy) + c; M(1,2) = (one_c * yz) - xs; M(2,0) = (one_c * zx) - ys; M(2,1) = (one_c * yz) + xs; M(2,2) = (one_c * zz) + c; #undef M } /////////////////////////////////////////////////////////////////////////////// // Creates a 4x4 rotation matrix, takes radians NOT degrees void m3dRotationMatrix44(M3DMatrix44d m, double angle, double x, double y, double z) { double mag, s, c; double xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c; s = sin(angle); c = cos(angle); mag = sqrt( x*x + y*y + z*z ); // Identity matrix if (mag == 0.0) { m3dLoadIdentity44(m); return; } // Rotation matrix is normalized x /= mag; y /= mag; z /= mag; #define M(row,col) m[col*4+row] xx = x * x; yy = y * y; zz = z * z; xy = x * y; yz = y * z; zx = z * x; xs = x * s; ys = y * s; zs = z * s; one_c = 1.0f - c; M(0,0) = (one_c * xx) + c; M(0,