tge/lib/opengl2d3d/glu2d3d.cc
2017-04-17 06:17:10 -06:00

1251 lines
31 KiB
C++
Executable File

//-----------------------------------------------------------------------------
// Torque Game Engine
// Quake GL DirectX wrapper
//-----------------------------------------------------------------------------
#include "opengl2d3d/glu2d3d.h"
GLAPI BOOL GLAPIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
hModule;
lpReserved;
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
case DLL_THREAD_ATTACH:
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
break;
}
return TRUE;
}
extern "C" {
GLAPI const GLubyte* GLAPIENTRY gluErrorString(GLenum errorCode)
{
/* GLU Errors */
if (errorCode == GLU_NO_ERROR) {
return (GLubyte *) "no error";
}
else if (errorCode == GLU_INVALID_ENUM) {
return (GLubyte *) "invalid enum";
}
else if (errorCode == GLU_INVALID_VALUE) {
return (GLubyte *) "invalid value";
}
else if (errorCode == GLU_OUT_OF_MEMORY) {
return (GLubyte *) "out of memory";
}
else {
return NULL;
}
}
GLAPI const GLubyte* GLAPIENTRY gluGetString(GLenum name)
{
static char *extensions = "";
static char *version = "1.0 GarageGames";
switch (name) {
case GLU_EXTENSIONS:
return (GLubyte *) extensions;
case GLU_VERSION:
return (GLubyte *) version;
default:
return NULL;
}
}
GLAPI void GLAPIENTRY gluOrtho2D(GLdouble left, GLdouble right, GLdouble bottom, GLdouble top)
{
glOrtho(left, right, bottom, top, -1.0, 1.0);
}
GLAPI void GLAPIENTRY gluPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar)
{
GLdouble xmin, xmax, ymin, ymax;
ymax = zNear * tan(fovy * M_PI / 360.0);
ymin = -ymax;
xmin = ymin * aspect;
xmax = ymax * aspect;
glFrustum(xmin, xmax, ymin, ymax, zNear, zFar);
}
GLAPI void GLAPIENTRY gluPickMatrix(GLdouble x, GLdouble y, GLdouble width, GLdouble height, const GLint viewport[4])
{
GLfloat m[16];
GLfloat sx, sy;
GLfloat tx, ty;
sx = (GLfloat) (viewport[2] / width);
sy = (GLfloat) (viewport[3] / height);
tx = (GLfloat) ((viewport[2] + 2.0 * (viewport[0] - x)) / width);
ty = (GLfloat) ((viewport[3] + 2.0 * (viewport[1] - y)) / height);
#define M(row,col) m[col*4+row]
M(0, 0) = sx;
M(0, 1) = 0.0;
M(0, 2) = 0.0;
M(0, 3) = tx;
M(1, 0) = 0.0;
M(1, 1) = sy;
M(1, 2) = 0.0;
M(1, 3) = ty;
M(2, 0) = 0.0;
M(2, 1) = 0.0;
M(2, 2) = 1.0;
M(2, 3) = 0.0;
M(3, 0) = 0.0;
M(3, 1) = 0.0;
M(3, 2) = 0.0;
M(3, 3) = 1.0;
#undef M
glMultMatrixf(m);
}
GLAPI void GLAPIENTRY gluLookAt(GLdouble eyex, GLdouble eyey, GLdouble eyez, GLdouble centerx, GLdouble centery, GLdouble centerz, GLdouble upx, GLdouble upy, GLdouble upz)
{
GLdouble m[16];
GLdouble x[3], y[3], z[3];
GLdouble mag;
/* Make rotation matrix */
/* Z vector */
z[0] = eyex - centerx;
z[1] = eyey - centery;
z[2] = eyez - centerz;
mag = sqrt(z[0] * z[0] + z[1] * z[1] + z[2] * z[2]);
if (mag) { /* mpichler, 19950515 */
z[0] /= mag;
z[1] /= mag;
z[2] /= mag;
}
/* Y vector */
y[0] = upx;
y[1] = upy;
y[2] = upz;
/* X vector = Y cross Z */
x[0] = y[1] * z[2] - y[2] * z[1];
x[1] = -y[0] * z[2] + y[2] * z[0];
x[2] = y[0] * z[1] - y[1] * z[0];
/* Recompute Y = Z cross X */
y[0] = z[1] * x[2] - z[2] * x[1];
y[1] = -z[0] * x[2] + z[2] * x[0];
y[2] = z[0] * x[1] - z[1] * x[0];
/* mpichler, 19950515 */
/* cross product gives area of parallelogram, which is < 1.0 for
* non-perpendicular unit-length vectors; so normalize x, y here
*/
mag = sqrt(x[0] * x[0] + x[1] * x[1] + x[2] * x[2]);
if (mag) {
x[0] /= mag;
x[1] /= mag;
x[2] /= mag;
}
mag = sqrt(y[0] * y[0] + y[1] * y[1] + y[2] * y[2]);
if (mag) {
y[0] /= mag;
y[1] /= mag;
y[2] /= mag;
}
#define M(row,col) m[col*4+row]
M(0, 0) = x[0];
M(0, 1) = x[1];
M(0, 2) = x[2];
M(0, 3) = 0.0;
M(1, 0) = y[0];
M(1, 1) = y[1];
M(1, 2) = y[2];
M(1, 3) = 0.0;
M(2, 0) = z[0];
M(2, 1) = z[1];
M(2, 2) = z[2];
M(2, 3) = 0.0;
M(3, 0) = 0.0;
M(3, 1) = 0.0;
M(3, 2) = 0.0;
M(3, 3) = 1.0;
#undef M
glMultMatrixd(m);
/* Translate Eye to Origin */
glTranslated(-eyex, -eyey, -eyez);
}
/*
* Transform a point (column vector) by a 4x4 matrix. I.e. out = m * in
* Input: m - the 4x4 matrix
* in - the 4x1 vector
* Output: out - the resulting 4x1 vector.
*/
static void transform_point(GLdouble out[4], const GLdouble m[16], const GLdouble in[4])
{
#define M(row,col) m[col*4+row]
out[0] =
M(0, 0) * in[0] + M(0, 1) * in[1] + M(0, 2) * in[2] + M(0, 3) * in[3];
out[1] =
M(1, 0) * in[0] + M(1, 1) * in[1] + M(1, 2) * in[2] + M(1, 3) * in[3];
out[2] =
M(2, 0) * in[0] + M(2, 1) * in[1] + M(2, 2) * in[2] + M(2, 3) * in[3];
out[3] =
M(3, 0) * in[0] + M(3, 1) * in[1] + M(3, 2) * in[2] + M(3, 3) * in[3];
#undef M
}
/*
* Perform a 4x4 matrix multiplication (product = a x b).
* Input: a, b - matrices to multiply
* Output: product - product of a and b
*/
static void matmul(GLdouble * product, const GLdouble * a, const GLdouble * b)
{
/* This matmul was contributed by Thomas Malik */
GLdouble temp[16];
GLint i;
#define A(row,col) a[(col<<2)+row]
#define B(row,col) b[(col<<2)+row]
#define T(row,col) temp[(col<<2)+row]
/* i-te Zeile */
for (i = 0; i < 4; i++) {
T(i, 0) =
A(i, 0) * B(0, 0) + A(i, 1) * B(1, 0) + A(i, 2) * B(2, 0) + A(i,
3) *
B(3, 0);
T(i, 1) =
A(i, 0) * B(0, 1) + A(i, 1) * B(1, 1) + A(i, 2) * B(2, 1) + A(i,
3) *
B(3, 1);
T(i, 2) =
A(i, 0) * B(0, 2) + A(i, 1) * B(1, 2) + A(i, 2) * B(2, 2) + A(i,
3) *
B(3, 2);
T(i, 3) =
A(i, 0) * B(0, 3) + A(i, 1) * B(1, 3) + A(i, 2) * B(2, 3) + A(i,
3) *
B(3, 3);
}
#undef A
#undef B
#undef T
memcpy(product, temp, 16 * sizeof(GLdouble));
}
/*
* Compute inverse of 4x4 transformation matrix.
* Code contributed by Jacques Leroy jle@star.be
* Return GL_TRUE for success, GL_FALSE for failure (singular matrix)
*/
static GLboolean invert_matrix(const GLdouble * m, GLdouble * out)
{
/* NB. OpenGL Matrices are COLUMN major. */
#define SWAP_ROWS(a, b) { GLdouble *_tmp = a; (a)=(b); (b)=_tmp; }
#define MAT(m,r,c) (m)[(c)*4+(r)]
GLdouble wtmp[4][8];
GLdouble m0, m1, m2, m3, s;
GLdouble *r0, *r1, *r2, *r3;
r0 = wtmp[0], r1 = wtmp[1], r2 = wtmp[2], r3 = wtmp[3];
r0[0] = MAT(m, 0, 0), r0[1] = MAT(m, 0, 1),
r0[2] = MAT(m, 0, 2), r0[3] = MAT(m, 0, 3),
r0[4] = 1.0, r0[5] = r0[6] = r0[7] = 0.0,
r1[0] = MAT(m, 1, 0), r1[1] = MAT(m, 1, 1),
r1[2] = MAT(m, 1, 2), r1[3] = MAT(m, 1, 3),
r1[5] = 1.0, r1[4] = r1[6] = r1[7] = 0.0,
r2[0] = MAT(m, 2, 0), r2[1] = MAT(m, 2, 1),
r2[2] = MAT(m, 2, 2), r2[3] = MAT(m, 2, 3),
r2[6] = 1.0, r2[4] = r2[5] = r2[7] = 0.0,
r3[0] = MAT(m, 3, 0), r3[1] = MAT(m, 3, 1),
r3[2] = MAT(m, 3, 2), r3[3] = MAT(m, 3, 3),
r3[7] = 1.0, r3[4] = r3[5] = r3[6] = 0.0;
/* choose pivot - or die */
if (fabs(r3[0]) > fabs(r2[0]))
SWAP_ROWS(r3, r2);
if (fabs(r2[0]) > fabs(r1[0]))
SWAP_ROWS(r2, r1);
if (fabs(r1[0]) > fabs(r0[0]))
SWAP_ROWS(r1, r0);
if (0.0 == r0[0])
return GL_FALSE;
/* eliminate first variable */
m1 = r1[0] / r0[0];
m2 = r2[0] / r0[0];
m3 = r3[0] / r0[0];
s = r0[1];
r1[1] -= m1 * s;
r2[1] -= m2 * s;
r3[1] -= m3 * s;
s = r0[2];
r1[2] -= m1 * s;
r2[2] -= m2 * s;
r3[2] -= m3 * s;
s = r0[3];
r1[3] -= m1 * s;
r2[3] -= m2 * s;
r3[3] -= m3 * s;
s = r0[4];
if (s != 0.0) {
r1[4] -= m1 * s;
r2[4] -= m2 * s;
r3[4] -= m3 * s;
}
s = r0[5];
if (s != 0.0) {
r1[5] -= m1 * s;
r2[5] -= m2 * s;
r3[5] -= m3 * s;
}
s = r0[6];
if (s != 0.0) {
r1[6] -= m1 * s;
r2[6] -= m2 * s;
r3[6] -= m3 * s;
}
s = r0[7];
if (s != 0.0) {
r1[7] -= m1 * s;
r2[7] -= m2 * s;
r3[7] -= m3 * s;
}
/* choose pivot - or die */
if (fabs(r3[1]) > fabs(r2[1]))
SWAP_ROWS(r3, r2);
if (fabs(r2[1]) > fabs(r1[1]))
SWAP_ROWS(r2, r1);
if (0.0 == r1[1])
return GL_FALSE;
/* eliminate second variable */
m2 = r2[1] / r1[1];
m3 = r3[1] / r1[1];
r2[2] -= m2 * r1[2];
r3[2] -= m3 * r1[2];
r2[3] -= m2 * r1[3];
r3[3] -= m3 * r1[3];
s = r1[4];
if (0.0 != s) {
r2[4] -= m2 * s;
r3[4] -= m3 * s;
}
s = r1[5];
if (0.0 != s) {
r2[5] -= m2 * s;
r3[5] -= m3 * s;
}
s = r1[6];
if (0.0 != s) {
r2[6] -= m2 * s;
r3[6] -= m3 * s;
}
s = r1[7];
if (0.0 != s) {
r2[7] -= m2 * s;
r3[7] -= m3 * s;
}
/* choose pivot - or die */
if (fabs(r3[2]) > fabs(r2[2]))
SWAP_ROWS(r3, r2);
if (0.0 == r2[2])
return GL_FALSE;
/* eliminate third variable */
m3 = r3[2] / r2[2];
r3[3] -= m3 * r2[3], r3[4] -= m3 * r2[4],
r3[5] -= m3 * r2[5], r3[6] -= m3 * r2[6], r3[7] -= m3 * r2[7];
/* last check */
if (0.0 == r3[3])
return GL_FALSE;
s = 1.0 / r3[3]; /* now back substitute row 3 */
r3[4] *= s;
r3[5] *= s;
r3[6] *= s;
r3[7] *= s;
m2 = r2[3]; /* now back substitute row 2 */
s = 1.0 / r2[2];
r2[4] = s * (r2[4] - r3[4] * m2), r2[5] = s * (r2[5] - r3[5] * m2),
r2[6] = s * (r2[6] - r3[6] * m2), r2[7] = s * (r2[7] - r3[7] * m2);
m1 = r1[3];
r1[4] -= r3[4] * m1, r1[5] -= r3[5] * m1,
r1[6] -= r3[6] * m1, r1[7] -= r3[7] * m1;
m0 = r0[3];
r0[4] -= r3[4] * m0, r0[5] -= r3[5] * m0,
r0[6] -= r3[6] * m0, r0[7] -= r3[7] * m0;
m1 = r1[2]; /* now back substitute row 1 */
s = 1.0 / r1[1];
r1[4] = s * (r1[4] - r2[4] * m1), r1[5] = s * (r1[5] - r2[5] * m1),
r1[6] = s * (r1[6] - r2[6] * m1), r1[7] = s * (r1[7] - r2[7] * m1);
m0 = r0[2];
r0[4] -= r2[4] * m0, r0[5] -= r2[5] * m0,
r0[6] -= r2[6] * m0, r0[7] -= r2[7] * m0;
m0 = r0[1]; /* now back substitute row 0 */
s = 1.0 / r0[0];
r0[4] = s * (r0[4] - r1[4] * m0), r0[5] = s * (r0[5] - r1[5] * m0),
r0[6] = s * (r0[6] - r1[6] * m0), r0[7] = s * (r0[7] - r1[7] * m0);
MAT(out, 0, 0) = r0[4];
MAT(out, 0, 1) = r0[5], MAT(out, 0, 2) = r0[6];
MAT(out, 0, 3) = r0[7], MAT(out, 1, 0) = r1[4];
MAT(out, 1, 1) = r1[5], MAT(out, 1, 2) = r1[6];
MAT(out, 1, 3) = r1[7], MAT(out, 2, 0) = r2[4];
MAT(out, 2, 1) = r2[5], MAT(out, 2, 2) = r2[6];
MAT(out, 2, 3) = r2[7], MAT(out, 3, 0) = r3[4];
MAT(out, 3, 1) = r3[5], MAT(out, 3, 2) = r3[6];
MAT(out, 3, 3) = r3[7];
return GL_TRUE;
#undef MAT
#undef SWAP_ROWS
}
/* projection du point (objx,objy,obz) sur l'ecran (winx,winy,winz) */
GLAPI GLint GLAPIENTRY gluProject(GLdouble objx, GLdouble objy, GLdouble objz,
const GLdouble model[16], const GLdouble proj[16],
const GLint viewport[4],
GLdouble * winx, GLdouble * winy, GLdouble * winz)
{
/* matrice de transformation */
GLdouble in[4], out[4];
/* initilise la matrice et le vecteur a transformer */
in[0] = objx;
in[1] = objy;
in[2] = objz;
in[3] = 1.0;
transform_point(out, model, in);
transform_point(in, proj, out);
/* d'ou le resultat normalise entre -1 et 1 */
if (in[3] == 0.0)
return GL_FALSE;
in[0] /= in[3];
in[1] /= in[3];
in[2] /= in[3];
/* en coordonnees ecran */
*winx = viewport[0] + (1 + in[0]) * viewport[2] / 2;
*winy = viewport[1] + (1 + in[1]) * viewport[3] / 2;
/* entre 0 et 1 suivant z */
*winz = (1 + in[2]) / 2;
return GL_TRUE;
}
/* transformation du point ecran (winx,winy,winz) en point objet */
GLAPI GLint GLAPIENTRY gluUnProject(GLdouble winx, GLdouble winy, GLdouble winz,
const GLdouble model[16], const GLdouble proj[16],
const GLint viewport[4],
GLdouble * objx, GLdouble * objy, GLdouble * objz)
{
/* matrice de transformation */
GLdouble m[16], A[16];
GLdouble in[4], out[4];
/* transformation coordonnees normalisees entre -1 et 1 */
in[0] = (winx - viewport[0]) * 2 / viewport[2] - 1.0;
in[1] = (winy - viewport[1]) * 2 / viewport[3] - 1.0;
in[2] = 2 * winz - 1.0;
in[3] = 1.0;
/* calcul transformation inverse */
matmul(A, proj, model);
invert_matrix(A, m);
/* d'ou les coordonnees objets */
transform_point(out, m, in);
if (out[3] == 0.0)
return GL_FALSE;
*objx = out[0] / out[3];
*objy = out[1] / out[3];
*objz = out[2] / out[3];
return GL_TRUE;
}
GLAPI GLint GLAPIENTRY gluScaleImage(GLenum format,
GLsizei widthin, GLsizei heightin,
GLenum typein, const void *datain,
GLsizei widthout, GLsizei heightout,
GLenum typeout, void *dataout)
{
GLint components, i, j, k;
GLfloat *tempin, *tempout;
GLfloat sx, sy;
GLint unpackrowlength, unpackalignment, unpackskiprows, unpackskippixels;
GLint packrowlength, packalignment, packskiprows, packskippixels;
GLint sizein, sizeout;
GLint rowstride, rowlen;
/* Determine number of components per pixel */
switch (format) {
case GL_COLOR_INDEX:
case GL_STENCIL_INDEX:
case GL_DEPTH_COMPONENT:
case GL_RED:
case GL_GREEN:
case GL_BLUE:
case GL_ALPHA:
case GL_LUMINANCE:
components = 1;
break;
case GL_LUMINANCE_ALPHA:
components = 2;
break;
case GL_RGB:
case GL_BGR:
components = 3;
break;
case GL_RGBA:
case GL_BGRA:
#ifdef GL_EXT_abgr
case GL_ABGR_EXT:
#endif
components = 4;
break;
default:
return GLU_INVALID_ENUM;
}
/* Determine bytes per input datum */
switch (typein) {
case GL_UNSIGNED_BYTE:
sizein = sizeof(GLubyte);
break;
case GL_BYTE:
sizein = sizeof(GLbyte);
break;
case GL_UNSIGNED_SHORT:
sizein = sizeof(GLushort);
break;
case GL_SHORT:
sizein = sizeof(GLshort);
break;
case GL_UNSIGNED_INT:
sizein = sizeof(GLuint);
break;
case GL_INT:
sizein = sizeof(GLint);
break;
case GL_FLOAT:
sizein = sizeof(GLfloat);
break;
case GL_BITMAP:
/* not implemented yet */
default:
return GL_INVALID_ENUM;
}
/* Determine bytes per output datum */
switch (typeout) {
case GL_UNSIGNED_BYTE:
sizeout = sizeof(GLubyte);
break;
case GL_BYTE:
sizeout = sizeof(GLbyte);
break;
case GL_UNSIGNED_SHORT:
sizeout = sizeof(GLushort);
break;
case GL_SHORT:
sizeout = sizeof(GLshort);
break;
case GL_UNSIGNED_INT:
sizeout = sizeof(GLuint);
break;
case GL_INT:
sizeout = sizeof(GLint);
break;
case GL_FLOAT:
sizeout = sizeof(GLfloat);
break;
case GL_BITMAP:
/* not implemented yet */
default:
return GL_INVALID_ENUM;
}
/* Get glPixelStore state */
glGetIntegerv(GL_UNPACK_ROW_LENGTH, &unpackrowlength);
glGetIntegerv(GL_UNPACK_ALIGNMENT, &unpackalignment);
glGetIntegerv(GL_UNPACK_SKIP_ROWS, &unpackskiprows);
glGetIntegerv(GL_UNPACK_SKIP_PIXELS, &unpackskippixels);
glGetIntegerv(GL_PACK_ROW_LENGTH, &packrowlength);
glGetIntegerv(GL_PACK_ALIGNMENT, &packalignment);
glGetIntegerv(GL_PACK_SKIP_ROWS, &packskiprows);
glGetIntegerv(GL_PACK_SKIP_PIXELS, &packskippixels);
/* Allocate storage for intermediate images */
tempin = (GLfloat *) malloc(widthin * heightin
* components * sizeof(GLfloat));
if (!tempin) {
return GLU_OUT_OF_MEMORY;
}
tempout = (GLfloat *) malloc(widthout * heightout
* components * sizeof(GLfloat));
if (!tempout) {
free(tempin);
return GLU_OUT_OF_MEMORY;
}
/*
* Unpack the pixel data and convert to floating point
*/
if (unpackrowlength > 0) {
rowlen = unpackrowlength;
}
else {
rowlen = widthin;
}
if (sizein >= unpackalignment) {
rowstride = components * rowlen;
}
else {
rowstride = unpackalignment / sizein
* CEILING(components * rowlen * sizein, unpackalignment);
}
switch (typein) {
case GL_UNSIGNED_BYTE:
k = 0;
for (i = 0; i < heightin; i++) {
GLubyte *ubptr = (GLubyte *) datain
+ i * rowstride
+ unpackskiprows * rowstride + unpackskippixels * components;
for (j = 0; j < widthin * components; j++) {
dummy(j, k);
tempin[k++] = (GLfloat) * ubptr++;
}
}
break;
case GL_BYTE:
k = 0;
for (i = 0; i < heightin; i++) {
GLbyte *bptr = (GLbyte *) datain
+ i * rowstride
+ unpackskiprows * rowstride + unpackskippixels * components;
for (j = 0; j < widthin * components; j++) {
dummy(j, k);
tempin[k++] = (GLfloat) * bptr++;
}
}
break;
case GL_UNSIGNED_SHORT:
k = 0;
for (i = 0; i < heightin; i++) {
GLushort *usptr = (GLushort *) datain
+ i * rowstride
+ unpackskiprows * rowstride + unpackskippixels * components;
for (j = 0; j < widthin * components; j++) {
dummy(j, k);
tempin[k++] = (GLfloat) * usptr++;
}
}
break;
case GL_SHORT:
k = 0;
for (i = 0; i < heightin; i++) {
GLshort *sptr = (GLshort *) datain
+ i * rowstride
+ unpackskiprows * rowstride + unpackskippixels * components;
for (j = 0; j < widthin * components; j++) {
dummy(j, k);
tempin[k++] = (GLfloat) * sptr++;
}
}
break;
case GL_UNSIGNED_INT:
k = 0;
for (i = 0; i < heightin; i++) {
GLuint *uiptr = (GLuint *) datain
+ i * rowstride
+ unpackskiprows * rowstride + unpackskippixels * components;
for (j = 0; j < widthin * components; j++) {
dummy(j, k);
tempin[k++] = (GLfloat) * uiptr++;
}
}
break;
case GL_INT:
k = 0;
for (i = 0; i < heightin; i++) {
GLint *iptr = (GLint *) datain
+ i * rowstride
+ unpackskiprows * rowstride + unpackskippixels * components;
for (j = 0; j < widthin * components; j++) {
dummy(j, k);
tempin[k++] = (GLfloat) * iptr++;
}
}
break;
case GL_FLOAT:
k = 0;
for (i = 0; i < heightin; i++) {
GLfloat *fptr = (GLfloat *) datain
+ i * rowstride
+ unpackskiprows * rowstride + unpackskippixels * components;
for (j = 0; j < widthin * components; j++) {
dummy(j, k);
tempin[k++] = *fptr++;
}
}
break;
default:
return GLU_INVALID_ENUM;
}
/*
* Scale the image!
*/
if (widthout > 1)
sx = (GLfloat) (widthin - 1) / (GLfloat) (widthout - 1);
else
sx = (GLfloat) (widthin - 1);
if (heightout > 1)
sy = (GLfloat) (heightin - 1) / (GLfloat) (heightout - 1);
else
sy = (GLfloat) (heightin - 1);
/*#define POINT_SAMPLE*/
#ifdef POINT_SAMPLE
for (i = 0; i < heightout; i++) {
GLint ii = i * sy;
for (j = 0; j < widthout; j++) {
GLint jj = j * sx;
GLfloat *src = tempin + (ii * widthin + jj) * components;
GLfloat *dst = tempout + (i * widthout + j) * components;
for (k = 0; k < components; k++) {
*dst++ = *src++;
}
}
}
#else
if (sx < 1.0 && sy < 1.0) {
/* magnify both width and height: use weighted sample of 4 pixels */
GLint i0, i1, j0, j1;
GLfloat alpha, beta;
GLfloat *src00, *src01, *src10, *src11;
GLfloat s1, s2;
GLfloat *dst;
for (i = 0; i < heightout; i++) {
i0 = (GLint) (i * sy);
i1 = i0 + 1;
if (i1 >= heightin)
i1 = heightin - 1;
/* i1 = (i+1) * sy - EPSILON;*/
alpha = i * sy - i0;
for (j = 0; j < widthout; j++) {
j0 = (GLint) (j * sx);
j1 = j0 + 1;
if (j1 >= widthin)
j1 = widthin - 1;
/* j1 = (j+1) * sx - EPSILON; */
beta = j * sx - j0;
/* compute weighted average of pixels in rect (i0,j0)-(i1,j1) */
src00 = tempin + (i0 * widthin + j0) * components;
src01 = tempin + (i0 * widthin + j1) * components;
src10 = tempin + (i1 * widthin + j0) * components;
src11 = tempin + (i1 * widthin + j1) * components;
dst = tempout + (i * widthout + j) * components;
for (k = 0; k < components; k++) {
s1 = (GLfloat) (*src00++ * (1.0 - beta) + *src01++ * beta);
s2 = (GLfloat) (*src10++ * (1.0 - beta) + *src11++ * beta);
*dst++ = (GLfloat) (s1 * (1.0 - alpha) + s2 * alpha);
}
}
}
}
else {
/* shrink width and/or height: use an unweighted box filter */
GLint i0, i1;
GLint j0, j1;
GLint ii, jj;
GLfloat sum, *dst;
for (i = 0; i < heightout; i++) {
i0 = (GLint) (i * sy);
i1 = i0 + 1;
if (i1 >= heightin)
i1 = heightin - 1;
/* i1 = (i+1) * sy - EPSILON; */
for (j = 0; j < widthout; j++) {
j0 = (GLint) (j * sx);
j1 = j0 + 1;
if (j1 >= widthin)
j1 = widthin - 1;
/* j1 = (j+1) * sx - EPSILON; */
dst = tempout + (i * widthout + j) * components;
/* compute average of pixels in the rectangle (i0,j0)-(i1,j1) */
for (k = 0; k < components; k++) {
sum = 0.0;
for (ii = i0; ii <= i1; ii++) {
for (jj = j0; jj <= j1; jj++) {
sum += *(tempin + (ii * widthin + jj) * components + k);
}
}
sum /= (j1 - j0 + 1) * (i1 - i0 + 1);
*dst++ = sum;
}
}
}
}
#endif
/*
* Return output image
*/
if (packrowlength > 0) {
rowlen = packrowlength;
}
else {
rowlen = widthout;
}
if (sizeout >= packalignment) {
rowstride = components * rowlen;
}
else {
rowstride = packalignment / sizeout
* CEILING(components * rowlen * sizeout, packalignment);
}
switch (typeout) {
case GL_UNSIGNED_BYTE:
k = 0;
for (i = 0; i < heightout; i++) {
GLubyte *ubptr = (GLubyte *) dataout
+ i * rowstride
+ packskiprows * rowstride + packskippixels * components;
for (j = 0; j < widthout * components; j++) {
dummy(j, k + i);
*ubptr++ = (GLubyte) tempout[k++];
}
}
break;
case GL_BYTE:
k = 0;
for (i = 0; i < heightout; i++) {
GLbyte *bptr = (GLbyte *) dataout
+ i * rowstride
+ packskiprows * rowstride + packskippixels * components;
for (j = 0; j < widthout * components; j++) {
dummy(j, k + i);
*bptr++ = (GLbyte) tempout[k++];
}
}
break;
case GL_UNSIGNED_SHORT:
k = 0;
for (i = 0; i < heightout; i++) {
GLushort *usptr = (GLushort *) dataout
+ i * rowstride
+ packskiprows * rowstride + packskippixels * components;
for (j = 0; j < widthout * components; j++) {
dummy(j, k + i);
*usptr++ = (GLushort) tempout[k++];
}
}
break;
case GL_SHORT:
k = 0;
for (i = 0; i < heightout; i++) {
GLshort *sptr = (GLshort *) dataout
+ i * rowstride
+ packskiprows * rowstride + packskippixels * components;
for (j = 0; j < widthout * components; j++) {
dummy(j, k + i);
*sptr++ = (GLshort) tempout[k++];
}
}
break;
case GL_UNSIGNED_INT:
k = 0;
for (i = 0; i < heightout; i++) {
GLuint *uiptr = (GLuint *) dataout
+ i * rowstride
+ packskiprows * rowstride + packskippixels * components;
for (j = 0; j < widthout * components; j++) {
dummy(j, k + i);
*uiptr++ = (GLuint) tempout[k++];
}
}
break;
case GL_INT:
k = 0;
for (i = 0; i < heightout; i++) {
GLint *iptr = (GLint *) dataout
+ i * rowstride
+ packskiprows * rowstride + packskippixels * components;
for (j = 0; j < widthout * components; j++) {
dummy(j, k + i);
*iptr++ = (GLint) tempout[k++];
}
}
break;
case GL_FLOAT:
k = 0;
for (i = 0; i < heightout; i++) {
GLfloat *fptr = (GLfloat *) dataout
+ i * rowstride
+ packskiprows * rowstride + packskippixels * components;
for (j = 0; j < widthout * components; j++) {
dummy(j, k + i);
*fptr++ = tempout[k++];
}
}
break;
default:
return GLU_INVALID_ENUM;
}
/* free temporary image storage */
free(tempin);
free(tempout);
return 0;
}
/*
* Return the largest k such that 2^k <= n.
*/
static GLint ilog2(GLint n)
{
GLint k;
if (n <= 0)
return 0;
for (k = 0; n >>= 1; k++) {}
return k;
}
/*
* Find the value nearest to n which is also a power of two.
*/
static GLint round2(GLint n)
{
GLint m;
for (m = 1; m < n; m *= 2) {}
/* m>=n */
if (m - n <= n - m / 2) {
return m;
}
else {
return m / 2;
}
}
/*
* WARNING: This function isn't finished and has never been tested!!!!
*/
GLAPI GLint GLAPIENTRY gluBuild1DMipmaps(GLenum target, GLint components,
GLsizei width, GLenum format, GLenum type, const void *data)
{
target;
GLubyte *texture;
GLint levels, max_levels;
GLint new_width, max_width;
GLint i, j, k, l;
if (width < 1)
return GLU_INVALID_VALUE;
glGetIntegerv(GL_MAX_TEXTURE_SIZE, &max_width);
max_levels = ilog2(max_width) + 1;
/* Compute how many mipmap images to make */
levels = ilog2(width) + 1;
if (levels > max_levels) {
levels = max_levels;
}
new_width = 1 << (levels - 1);
texture = (GLubyte *) malloc(new_width * components);
if (!texture) {
return GLU_OUT_OF_MEMORY;
}
if (width != new_width) {
/* initial rescaling */
switch (type) {
case GL_UNSIGNED_BYTE:
{
GLubyte *ub_data = (GLubyte *) data;
for (i = 0; i < new_width; i++) {
j = i * width / new_width;
for (k = 0; k < components; k++) {
texture[i * components + k] = ub_data[j * components + k];
}
}
}
break;
default:
/* Not implemented */
return GLU_ERROR;
}
}
/* generate and load mipmap images */
for (l = 0; l < levels; l++) {
glTexImage1D(GL_TEXTURE_1D, l, components, new_width, 0,
format, GL_UNSIGNED_BYTE, texture);
/* Scale image down to 1/2 size */
new_width = new_width / 2;
for (i = 0; i < new_width; i++) {
for (k = 0; k < components; k++) {
GLint sample1, sample2;
sample1 = (GLint) texture[i * 2 * components + k];
sample2 = (GLint) texture[(i * 2 + 1) * components + k];
texture[i * components + k] = (GLubyte) ((sample1 + sample2) / 2);
}
}
}
free(texture);
return 0;
}
/*
* Given an pixel format and datatype, return the number of bytes to
* store one pixel.
*/
static GLint bytes_per_pixel(GLenum format, GLenum type)
{
GLint n, m;
switch (format) {
case GL_COLOR_INDEX:
case GL_STENCIL_INDEX:
case GL_DEPTH_COMPONENT:
case GL_RED:
case GL_GREEN:
case GL_BLUE:
case GL_ALPHA:
case GL_LUMINANCE:
n = 1;
break;
case GL_LUMINANCE_ALPHA:
n = 2;
break;
case GL_RGB:
case GL_BGR:
n = 3;
break;
case GL_RGBA:
case GL_BGRA:
#ifdef GL_EXT_abgr
case GL_ABGR_EXT:
#endif
n = 4;
break;
default:
n = 0;
}
switch (type) {
case GL_UNSIGNED_BYTE:
m = sizeof(GLubyte);
break;
case GL_BYTE:
m = sizeof(GLbyte);
break;
case GL_BITMAP:
m = 1;
break;
case GL_UNSIGNED_SHORT:
m = sizeof(GLushort);
break;
case GL_SHORT:
m = sizeof(GLshort);
break;
case GL_UNSIGNED_INT:
m = sizeof(GLuint);
break;
case GL_INT:
m = sizeof(GLint);
break;
case GL_FLOAT:
m = sizeof(GLfloat);
break;
default:
m = 0;
}
return n * m;
}
GLAPI GLint GLAPIENTRY gluBuild2DMipmaps(GLenum target, GLint components,
GLsizei width, GLsizei height, GLenum format,
GLenum type, const void *data)
{
GLint w, h, maxsize;
void *image, *newimage;
GLint neww, newh, level, bpp;
int error;
GLboolean done;
GLint retval = 0;
GLint unpackrowlength, unpackalignment, unpackskiprows, unpackskippixels;
GLint packrowlength, packalignment, packskiprows, packskippixels;
if (width < 1 || height < 1)
return GLU_INVALID_VALUE;
glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxsize);
w = round2(width);
if (w > maxsize) {
w = maxsize;
}
h = round2(height);
if (h > maxsize) {
h = maxsize;
}
bpp = bytes_per_pixel(format, type);
if (bpp == 0) {
/* probably a bad format or type enum */
return GLU_INVALID_ENUM;
}
/* Get current glPixelStore values */
glGetIntegerv(GL_UNPACK_ROW_LENGTH, &unpackrowlength);
glGetIntegerv(GL_UNPACK_ALIGNMENT, &unpackalignment);
glGetIntegerv(GL_UNPACK_SKIP_ROWS, &unpackskiprows);
glGetIntegerv(GL_UNPACK_SKIP_PIXELS, &unpackskippixels);
glGetIntegerv(GL_PACK_ROW_LENGTH, &packrowlength);
glGetIntegerv(GL_PACK_ALIGNMENT, &packalignment);
glGetIntegerv(GL_PACK_SKIP_ROWS, &packskiprows);
glGetIntegerv(GL_PACK_SKIP_PIXELS, &packskippixels);
/* set pixel packing */
glPixelStorei(GL_PACK_ROW_LENGTH, 0);
glPixelStorei(GL_PACK_ALIGNMENT, 1);
glPixelStorei(GL_PACK_SKIP_ROWS, 0);
glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
done = GL_FALSE;
if (w != width || h != height) {
/* must rescale image to get "top" mipmap texture image */
image = malloc((w + 4) * h * bpp);
if (!image) {
return GLU_OUT_OF_MEMORY;
}
error = gluScaleImage(format, width, height, type, data,
w, h, type, image);
if (error) {
retval = error;
done = GL_TRUE;
}
}
else {
image = (void *) data;
}
level = 0;
while (!done) {
if (image != data) {
/* set pixel unpacking */
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
}
glTexImage2D(target, level, components, w, h, 0, format, type, image);
if (w == 1 && h == 1)
break;
neww = (w < 2) ? 1 : w / 2;
newh = (h < 2) ? 1 : h / 2;
newimage = malloc((neww + 4) * newh * bpp);
if (!newimage) {
return GLU_OUT_OF_MEMORY;
}
error = gluScaleImage(format, w, h, type, image,
neww, newh, type, newimage);
if (error) {
retval = error;
done = GL_TRUE;
}
if (image != data) {
free(image);
}
image = newimage;
w = neww;
h = newh;
level++;
}
if (image != data) {
free(image);
}
/* Restore original glPixelStore state */
glPixelStorei(GL_UNPACK_ROW_LENGTH, unpackrowlength);
glPixelStorei(GL_UNPACK_ALIGNMENT, unpackalignment);
glPixelStorei(GL_UNPACK_SKIP_ROWS, unpackskiprows);
glPixelStorei(GL_UNPACK_SKIP_PIXELS, unpackskippixels);
glPixelStorei(GL_PACK_ROW_LENGTH, packrowlength);
glPixelStorei(GL_PACK_ALIGNMENT, packalignment);
glPixelStorei(GL_PACK_SKIP_ROWS, packskiprows);
glPixelStorei(GL_PACK_SKIP_PIXELS, packskippixels);
return retval;
}
}