Renamed gles_book_examples to gles2_book to make it shorter and more correct....

third_party/gles_book_examples/Common/Source/esTransform.c

-//
-// Book:      OpenGL(R) ES 2.0 Programming Guide
-// Authors:   Aaftab Munshi, Dan Ginsburg, Dave Shreiner
-// ISBN-10:   0321502795
-// ISBN-13:   9780321502797
-// Publisher: Addison-Wesley Professional
-// URLs:      http://safari.informit.com/9780321563835
-//            http://www.opengles-book.com
-//
-
-// ESUtil.c
-//
-//    A utility library for OpenGL ES.  This library provides a
-//    basic common framework for the example applications in the
-//    OpenGL ES 2.0 Programming Guide.
-//
-
-///
-//  Includes
-//
-#include "esUtil.h"
-#include <math.h>
-#include <string.h>
-
-#define PI 3.1415926535897932384626433832795f
-
-void esScale(ESMatrix *result, GLfloat sx, GLfloat sy, GLfloat sz)
-{
-    result->m[0][0] *= sx;
-    result->m[0][1] *= sx;
-    result->m[0][2] *= sx;
-    result->m[0][3] *= sx;
-
-    result->m[1][0] *= sy;
-    result->m[1][1] *= sy;
-    result->m[1][2] *= sy;
-    result->m[1][3] *= sy;
-
-    result->m[2][0] *= sz;
-    result->m[2][1] *= sz;
-    result->m[2][2] *= sz;
-    result->m[2][3] *= sz;
-}
-
-void esTranslate(ESMatrix *result, GLfloat tx, GLfloat ty, GLfloat tz)
-{
-    result->m[3][0] += (result->m[0][0] * tx + result->m[1][0] * ty + result->m[2][0] * tz);
-    result->m[3][1] += (result->m[0][1] * tx + result->m[1][1] * ty + result->m[2][1] * tz);
-    result->m[3][2] += (result->m[0][2] * tx + result->m[1][2] * ty + result->m[2][2] * tz);
-    result->m[3][3] += (result->m[0][3] * tx + result->m[1][3] * ty + result->m[2][3] * tz);
-}
-
-void esRotate(ESMatrix *result, GLfloat angle, GLfloat x, GLfloat y, GLfloat z)
-{
-   GLfloat sinAngle, cosAngle;
-   GLfloat mag = sqrtf(x * x + y * y + z * z);
-      
-   sinAngle = sinf ( angle * PI / 180.0f );
-   cosAngle = cosf ( angle * PI / 180.0f );
-   if ( mag > 0.0f )
-   {
-      GLfloat xx, yy, zz, xy, yz, zx, xs, ys, zs;
-      GLfloat oneMinusCos;
-      ESMatrix rotMat;
-   
-      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 * sinAngle;
-      ys = y * sinAngle;
-      zs = z * sinAngle;
-      oneMinusCos = 1.0f - cosAngle;
-
-      rotMat.m[0][0] = (oneMinusCos * xx) + cosAngle;
-      rotMat.m[0][1] = (oneMinusCos * xy) - zs;
-      rotMat.m[0][2] = (oneMinusCos * zx) + ys;
-      rotMat.m[0][3] = 0.0F; 
-
-      rotMat.m[1][0] = (oneMinusCos * xy) + zs;
-      rotMat.m[1][1] = (oneMinusCos * yy) + cosAngle;
-      rotMat.m[1][2] = (oneMinusCos * yz) - xs;
-      rotMat.m[1][3] = 0.0F;
-
-      rotMat.m[2][0] = (oneMinusCos * zx) - ys;
-      rotMat.m[2][1] = (oneMinusCos * yz) + xs;
-      rotMat.m[2][2] = (oneMinusCos * zz) + cosAngle;
-      rotMat.m[2][3] = 0.0F; 
-
-      rotMat.m[3][0] = 0.0F;
-      rotMat.m[3][1] = 0.0F;
-      rotMat.m[3][2] = 0.0F;
-      rotMat.m[3][3] = 1.0F;
-
-      esMatrixMultiply( result, &rotMat, result );
-   }
-}
-
-void esFrustum(ESMatrix *result, float left, float right, float bottom, float top, float nearZ, float farZ)
-{
-    float       deltaX = right - left;
-    float       deltaY = top - bottom;
-    float       deltaZ = farZ - nearZ;
-    ESMatrix    frust;
-
-    if ( (nearZ <= 0.0f) || (farZ <= 0.0f) ||
-         (deltaX <= 0.0f) || (deltaY <= 0.0f) || (deltaZ <= 0.0f) )
-         return;
-
-    frust.m[0][0] = 2.0f * nearZ / deltaX;
-    frust.m[0][1] = frust.m[0][2] = frust.m[0][3] = 0.0f;
-
-    frust.m[1][1] = 2.0f * nearZ / deltaY;
-    frust.m[1][0] = frust.m[1][2] = frust.m[1][3] = 0.0f;
-
-    frust.m[2][0] = (right + left) / deltaX;
-    frust.m[2][1] = (top + bottom) / deltaY;
-    frust.m[2][2] = -(nearZ + farZ) / deltaZ;
-    frust.m[2][3] = -1.0f;
-
-    frust.m[3][2] = -2.0f * nearZ * farZ / deltaZ;
-    frust.m[3][0] = frust.m[3][1] = frust.m[3][3] = 0.0f;
-
-    esMatrixMultiply(result, &frust, result);
-}
-
-
-void esPerspective(ESMatrix *result, float fovy, float aspect, float nearZ, float farZ)
-{
-   GLfloat frustumW, frustumH;
-   
-   frustumH = tanf( fovy / 360.0f * PI ) * nearZ;
-   frustumW = frustumH * aspect;
-
-   esFrustum( result, -frustumW, frustumW, -frustumH, frustumH, nearZ, farZ );
-}
-
-void esOrtho(ESMatrix *result, float left, float right, float bottom, float top, float nearZ, float farZ)
-{
-    float       deltaX = right - left;
-    float       deltaY = top - bottom;
-    float       deltaZ = farZ - nearZ;
-    ESMatrix    ortho;
-
-    if ( (deltaX == 0.0f) || (deltaY == 0.0f) || (deltaZ == 0.0f) )
-        return;
-
-    esMatrixLoadIdentity(&ortho);
-    ortho.m[0][0] = 2.0f / deltaX;
-    ortho.m[3][0] = -(right + left) / deltaX;
-    ortho.m[1][1] = 2.0f / deltaY;
-    ortho.m[3][1] = -(top + bottom) / deltaY;
-    ortho.m[2][2] = -2.0f / deltaZ;
-    ortho.m[3][2] = -(nearZ + farZ) / deltaZ;
-
-    esMatrixMultiply(result, &ortho, result);
-}
-
-
-void esMatrixMultiply(ESMatrix *result, ESMatrix *srcA, ESMatrix *srcB)
-{
-    ESMatrix    tmp;
-    int         i;
-
-        for (i=0; i<4; i++)
-        {
-                tmp.m[i][0] =   (srcA->m[i][0] * srcB->m[0][0]) +
-                                                (srcA->m[i][1] * srcB->m[1][0]) +
-                                                (srcA->m[i][2] * srcB->m[2][0]) +
-                                                (srcA->m[i][3] * srcB->m[3][0]) ;
-
-                tmp.m[i][1] =   (srcA->m[i][0] * srcB->m[0][1]) + 
-                                                (srcA->m[i][1] * srcB->m[1][1]) +
-                                                (srcA->m[i][2] * srcB->m[2][1]) +
-                                                (srcA->m[i][3] * srcB->m[3][1]) ;
-
-                tmp.m[i][2] =   (srcA->m[i][0] * srcB->m[0][2]) + 
-                                                (srcA->m[i][1] * srcB->m[1][2]) +
-                                                (srcA->m[i][2] * srcB->m[2][2]) +
-                                                (srcA->m[i][3] * srcB->m[3][2]) ;
-
-                tmp.m[i][3] =   (srcA->m[i][0] * srcB->m[0][3]) + 
-                                                (srcA->m[i][1] * srcB->m[1][3]) +
-                                                (srcA->m[i][2] * srcB->m[2][3]) +
-                                                (srcA->m[i][3] * srcB->m[3][3]) ;
-        }
-    memcpy(result, &tmp, sizeof(ESMatrix));
-}
-
-
-void esMatrixLoadIdentity(ESMatrix *result)
-{
-    memset(result, 0x0, sizeof(ESMatrix));
-    result->m[0][0] = 1.0f;
-    result->m[1][1] = 1.0f;
-    result->m[2][2] = 1.0f;
-    result->m[3][3] = 1.0f;
-}