mesa: Move glQueryMatrixxOES() implementation to core mesa

1 files changed, 199 insertions, 0 deletions

diff --git a/src/mesa/main/querymatrix.c b/src/mesa/main/querymatrix.c
new file mode 100644
index 0000000000..82b6fe7ab9
--- /dev/null
+++ b/src/mesa/main/querymatrix.c
@@ -0,0 +1,199 @@
+/**************************************************************************
+ *
+ * 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(WIN32) || defined(_WIN32_WCE)
+/* Oddly, the fpclassify() function doesn't exist in such a form
+ * on Windows.  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;
+    }
+}
+#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;
+}