add GLMatrix class

src/client/GL/GLMatrix.cc

@@ -0,0 +1,144 @@
+
+#include <math.h>
+#include <string.h>
+#include "GLMatrix.h"
+
+const GLMatrix GLMatrix::Identity;
+
+GLMatrix::GLMatrix()
+{
+    set_identity();
+}
+
+void GLMatrix::set_identity()
+{
+    memset(m_mat, 0, sizeof(m_mat));
+    for (int i = 0; i < 4; i++)
+        m_mat[i][i] = 1.0f;
+}
+
+GLMatrix operator*(const GLMatrix & left, const GLMatrix & right)
+{
+    GLMatrix result = left;
+    result.multiply(right);
+    return result;
+}
+
+void GLMatrix::multiply(const GLMatrix & other)
+{
+    GLMatrix tmp = *this;
+    for (int i = 0; i < 4; i++)
+    {
+        for (int j = 0; j < 4; j++)
+        {
+            GLfloat v = 0.0;
+            for (int p = 0; p < 4; p++)
+            {
+                v += tmp.m_mat[p][i] * other.m_mat[j][p];
+            }
+            m_mat[j][i] = v;
+        }
+    }
+}
+
+void GLMatrix::translate(GLfloat x, GLfloat y, GLfloat z)
+{
+    for (int i = 0; i < 4; i++)
+    {
+        m_mat[3][i] += m_mat[0][i] * x + m_mat[1][i] * y + m_mat[2][i] * z;
+    }
+}
+
+void GLMatrix::scale(GLfloat x, GLfloat y, GLfloat z)
+{
+    for (int i = 0; i < 4; i++)
+    {
+        m_mat[0][i] *= x;
+        m_mat[1][i] *= y;
+        m_mat[2][i] *= z;
+    }
+}
+
+void GLMatrix::rotate(GLfloat angle, GLfloat x, GLfloat y, GLfloat z)
+{
+    GLfloat p = x*x + y*y + z*z;
+    if (p != 1.0f)
+    {
+        GLfloat scale = sqrt(p);
+        x /= scale;
+        y /= scale;
+        z /= scale;
+    }
+    GLfloat c = cos(M_PI * angle / 180.0);
+    GLfloat s = sin(M_PI * angle / 180.0);
+    GLMatrix mult;
+    GLfloat oc = 1 - c;
+    mult.m_mat[0][0] = x * x * oc + c;
+    mult.m_mat[1][0] = x * y * oc - z * s;
+    mult.m_mat[2][0] = x * z * oc + y * s;
+    mult.m_mat[3][0] = 0.0;
+    mult.m_mat[0][1] = y * x * oc + z * s;
+    mult.m_mat[1][1] = y * y * oc + c;
+    mult.m_mat[2][1] = y * z * oc - x * s;
+    mult.m_mat[3][1] = 0.0;
+    mult.m_mat[0][2] = x * z * oc - y * s;
+    mult.m_mat[1][2] = y * z * oc + x * s;
+    mult.m_mat[2][2] = z * z * oc + c;
+    mult.m_mat[3][2] = 0.0;
+    mult.m_mat[0][3] = 0.0;
+    mult.m_mat[1][3] = 0.0;
+    mult.m_mat[2][3] = 0.0;
+    mult.m_mat[3][3] = 1.0;
+    *this = *this * mult;
+}
+
+void GLMatrix::frustum(GLfloat left, GLfloat right,
+        GLfloat bottom, GLfloat top,
+        GLfloat near, GLfloat far)
+{
+    GLMatrix mult;
+    GLfloat rl = right - left;
+    GLfloat tb = top - bottom;
+    GLfloat fn = far - near;
+    mult.m_mat[0][0] = 2 * near / rl;
+    mult.m_mat[2][0] = (right + left) / rl;
+    mult.m_mat[1][1] = 2 * near / tb;
+    mult.m_mat[2][1] = (top + bottom) / tb;
+    mult.m_mat[2][2] = - (far + near) / fn;
+    mult.m_mat[3][2] = - 2 * far * near / fn;
+    mult.m_mat[2][3] = -1.0;
+    mult.m_mat[3][3] = 0.0f;
+    multiply(mult);
+}
+
+void GLMatrix::perspective(GLfloat fovy, GLfloat aspect,
+        GLfloat near, GLfloat far)
+{
+    GLMatrix mult;
+    GLfloat f = 1.0 / tan(M_PI * fovy / 360.0);
+    GLfloat nf = near - far;
+    mult.m_mat[0][0] = f / aspect;
+    mult.m_mat[1][1] = f;
+    mult.m_mat[2][2] = (far + near) / nf;
+    mult.m_mat[3][2] = (2 * far * near) / nf;
+    mult.m_mat[2][3] = -1.0;
+    mult.m_mat[3][3] = 0.0f;
+    multiply(mult);
+}
+
+void GLMatrix::ortho(GLfloat left, GLfloat right,
+        GLfloat bottom, GLfloat top,
+        GLfloat near, GLfloat far)
+{
+    GLMatrix mult;
+    GLfloat rl = right - left;
+    GLfloat tb = top - bottom;
+    GLfloat fn = far - near;
+    mult.m_mat[0][0] = 2 / rl;
+    mult.m_mat[3][0] = - (right + left) / rl;
+    mult.m_mat[1][1] = 2 / tb;
+    mult.m_mat[3][1] = - (top + bottom) / tb;
+    mult.m_mat[2][2] = -2 / fn;
+    mult.m_mat[3][2] = - (far + near) / fn;
+    multiply(mult);
+}

src/client/GL/GLMatrix.h

@@ -0,0 +1,38 @@
+
+#ifndef GLMATRIX_H
+#define GLMATRIX_H
+
+#include <GL/glew.h>
+
+/**
+ * Store a 4x4 matrix of GLfloats with associated operations.
+ *
+ * Matrices are stored in column-major order.
+ */
+class GLMatrix
+{
+    public:
+        GLMatrix();
+        void set_identity();
+        void translate(GLfloat x, GLfloat y, GLfloat z);
+        void scale(GLfloat x, GLfloat y, GLfloat z);
+        void rotate(GLfloat angle, GLfloat x, GLfloat y, GLfloat z);
+        void multiply(const GLMatrix & other);
+        void frustum(GLfloat left, GLfloat right,
+                GLfloat bottom, GLfloat top,
+                GLfloat near, GLfloat far);
+        void perspective(GLfloat fovy, GLfloat aspect,
+                GLfloat near, GLfloat far);
+        void ortho(GLfloat left, GLfloat right,
+                GLfloat bottom, GLfloat top,
+                GLfloat near, GLfloat far);
+
+        friend GLMatrix operator*(const GLMatrix &, const GLMatrix &);
+
+        static const GLMatrix Identity;
+
+    protected:
+        GLfloat m_mat[4][4];
+};
+
+#endif