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Diffstat (limited to 'mesalib/src/mesa/main/querymatrix.c')
| -rw-r--r-- | mesalib/src/mesa/main/querymatrix.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/mesalib/src/mesa/main/querymatrix.c b/mesalib/src/mesa/main/querymatrix.c new file mode 100644 index 000000000..36236eb9a --- /dev/null +++ b/mesalib/src/mesa/main/querymatrix.c @@ -0,0 +1,216 @@ +/************************************************************************** + * + * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas. + * All Rights Reserved. + * + **************************************************************************/ + + +/** + * Code to implement GL_OES_query_matrix. See the spec at: + * http://www.khronos.org/registry/gles/extensions/OES/OES_query_matrix.txt + */ + + +#include <stdlib.h> +#include <math.h> +#include "GLES/gl.h" +#include "GLES/glext.h" + + +/** + * This is from the GL_OES_query_matrix extension specification: + * + * GLbitfield glQueryMatrixxOES( GLfixed mantissa[16], + * GLint exponent[16] ) + * mantissa[16] contains the contents of the current matrix in GLfixed + * format. exponent[16] contains the unbiased exponents applied to the + * matrix components, so that the internal representation of component i + * is close to mantissa[i] * 2^exponent[i]. The function returns a status + * word which is zero if all the components are valid. If + * status & (1<<i) != 0, the component i is invalid (e.g., NaN, Inf). + * The implementations are not required to keep track of overflows. In + * that case, the invalid bits are never set. + */ + +#define INT_TO_FIXED(x) ((GLfixed) ((x) << 16)) +#define FLOAT_TO_FIXED(x) ((GLfixed) ((x) * 65536.0)) + +#if defined(_MSC_VER) +/* Oddly, the fpclassify() function doesn't exist in such a form + * on MSVC. This is an implementation using slightly different + * lower-level Windows functions. + */ +#include <float.h> + +enum {FP_NAN, FP_INFINITE, FP_ZERO, FP_SUBNORMAL, FP_NORMAL} +fpclassify(double x) +{ + switch(_fpclass(x)) { + case _FPCLASS_SNAN: /* signaling NaN */ + case _FPCLASS_QNAN: /* quiet NaN */ + return FP_NAN; + case _FPCLASS_NINF: /* negative infinity */ + case _FPCLASS_PINF: /* positive infinity */ + return FP_INFINITE; + case _FPCLASS_NN: /* negative normal */ + case _FPCLASS_PN: /* positive normal */ + return FP_NORMAL; + case _FPCLASS_ND: /* negative denormalized */ + case _FPCLASS_PD: /* positive denormalized */ + return FP_SUBNORMAL; + case _FPCLASS_NZ: /* negative zero */ + case _FPCLASS_PZ: /* positive zero */ + return FP_ZERO; + default: + /* Should never get here; but if we do, this will guarantee + * that the pattern is not treated like a number. + */ + return FP_NAN; + } +} + +#elif defined(__APPLE__) || defined(__CYGWIN__) || defined(__FreeBSD__) || \ + defined(__OpenBSD__) || defined(__NetBSD__) || defined(__DragonFly__) || \ + (defined(__sun) && defined(__C99FEATURES__)) || defined(__MINGW32__) || \ + (defined(__sun) && defined(__GNUC__)) + +/* fpclassify is available. */ + +#elif !defined(_XOPEN_SOURCE) || _XOPEN_SOURCE < 600 + +enum {FP_NAN, FP_INFINITE, FP_ZERO, FP_SUBNORMAL, FP_NORMAL} +fpclassify(double x) +{ + /* XXX do something better someday */ + return FP_NORMAL; +} + +#endif + +extern GLbitfield GL_APIENTRY _es_QueryMatrixxOES(GLfixed mantissa[16], GLint exponent[16]); + +/* The Mesa functions we'll need */ +extern void GL_APIENTRY _mesa_GetIntegerv(GLenum pname, GLint *params); +extern void GL_APIENTRY _mesa_GetFloatv(GLenum pname, GLfloat *params); + +GLbitfield GL_APIENTRY _es_QueryMatrixxOES(GLfixed mantissa[16], GLint exponent[16]) +{ + GLfloat matrix[16]; + GLint tmp; + GLenum currentMode = GL_FALSE; + GLenum desiredMatrix = GL_FALSE; + /* The bitfield returns 1 for each component that is invalid (i.e. + * NaN or Inf). In case of error, everything is invalid. + */ + GLbitfield rv; + register unsigned int i; + unsigned int bit; + + /* This data structure defines the mapping between the current matrix + * mode and the desired matrix identifier. + */ + static struct { + GLenum currentMode; + GLenum desiredMatrix; + } modes[] = { + {GL_MODELVIEW, GL_MODELVIEW_MATRIX}, + {GL_PROJECTION, GL_PROJECTION_MATRIX}, + {GL_TEXTURE, GL_TEXTURE_MATRIX}, +#if 0 + /* this doesn't exist in GLES */ + {GL_COLOR, GL_COLOR_MATRIX}, +#endif + }; + + /* Call Mesa to get the current matrix in floating-point form. First, + * we have to figure out what the current matrix mode is. + */ + _mesa_GetIntegerv(GL_MATRIX_MODE, &tmp); + currentMode = (GLenum) tmp; + + /* The mode is either GL_FALSE, if for some reason we failed to query + * the mode, or a given mode from the above table. Search for the + * returned mode to get the desired matrix; if we don't find it, + * we can return immediately, as _mesa_GetInteger() will have + * logged the necessary error already. + */ + for (i = 0; i < sizeof(modes)/sizeof(modes[0]); i++) { + if (modes[i].currentMode == currentMode) { + desiredMatrix = modes[i].desiredMatrix; + break; + } + } + if (desiredMatrix == GL_FALSE) { + /* Early error means all values are invalid. */ + return 0xffff; + } + + /* Now pull the matrix itself. */ + _mesa_GetFloatv(desiredMatrix, matrix); + + rv = 0; + for (i = 0, bit = 1; i < 16; i++, bit<<=1) { + float normalizedFraction; + int exp; + + switch (fpclassify(matrix[i])) { + /* A "subnormal" or denormalized number is too small to be + * represented in normal format; but despite that it's a + * valid floating point number. FP_ZERO and FP_NORMAL + * are both valid as well. We should be fine treating + * these three cases as legitimate floating-point numbers. + */ + case FP_SUBNORMAL: + case FP_NORMAL: + case FP_ZERO: + normalizedFraction = (GLfloat)frexp(matrix[i], &exp); + mantissa[i] = FLOAT_TO_FIXED(normalizedFraction); + exponent[i] = (GLint) exp; + break; + + /* If the entry is not-a-number or an infinity, then the + * matrix component is invalid. The invalid flag for + * the component is already set; might as well set the + * other return values to known values. We'll set + * distinct values so that a savvy end user could determine + * whether the matrix component was a NaN or an infinity, + * but this is more useful for debugging than anything else + * since the standard doesn't specify any such magic + * values to return. + */ + case FP_NAN: + mantissa[i] = INT_TO_FIXED(0); + exponent[i] = (GLint) 0; + rv |= bit; + break; + + case FP_INFINITE: + /* Return +/- 1 based on whether it's a positive or + * negative infinity. + */ + if (matrix[i] > 0) { + mantissa[i] = INT_TO_FIXED(1); + } + else { + mantissa[i] = -INT_TO_FIXED(1); + } + exponent[i] = (GLint) 0; + rv |= bit; + break; + + /* We should never get here; but here's a catching case + * in case fpclassify() is returnings something unexpected. + */ + default: + mantissa[i] = INT_TO_FIXED(2); + exponent[i] = (GLint) 0; + rv |= bit; + break; + } + + } /* for each component */ + + /* All done */ + return rv; +} |