/gfx/angle/samples/gles2_book/Common/esTransform.c
C | 212 lines | 154 code | 40 blank | 18 comment | 12 complexity | 77ba0436eb2e2c4c3a1fe5b1aa6515e6 MD5 | raw file
Possible License(s): AGPL-1.0, MIT, BSD-3-Clause, Apache-2.0, LGPL-2.1, 0BSD, LGPL-3.0, MPL-2.0-no-copyleft-exception, GPL-2.0, JSON
- //
- // 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>
- #define PI 3.1415926535897932384626433832795f
- void ESUTIL_API
- 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 ESUTIL_API
- 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 ESUTIL_API
- 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 ESUTIL_API
- 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 ESUTIL_API
- 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 ESUTIL_API
- 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 ESUTIL_API
- 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 ESUTIL_API
- 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;
- }