Changes in uspace/lib/softrend/transform.c [071fefec:7dba813] in mainline

File:

• uspace/lib/softrend/transform.c (modified) (1 diff)

uspace/lib/softrend/transform.c

@@ -34 +34 @@
  */
 
-#include <math.h>
 #include "transform.h"
 
-void transform_product(transform_t *res, const transform_t *a,
-    const transform_t *b)
+void transform_multiply(transform_t *res, const transform_t *left, const transform_t *right)
 {
-        for (unsigned int i = 0; i < TRANSFORM_MATRIX_DIM; i++) {
-                for (unsigned int j = 0; j < TRANSFORM_MATRIX_DIM; j++) {
+        for (int i = 0; i < 3; ++i) {
+                for (int j = 0; j < 3; ++j) {
                         double comb = 0;
-                        
-                        for (unsigned int k = 0; k < TRANSFORM_MATRIX_DIM; k++)
-                                comb += a->matrix[i][k] * b->matrix[k][j];
-                        
-                        res->matrix[i][j] = comb;
+                        for (int k = 0; k < 3; ++k) {
+                                comb += left->m[i][k] * right->m[k][j];
+                        }
+                        res->m[i][j] = comb;
                 }
         }
 }
 
-void transform_invert(transform_t *trans)
+void transform_invert(transform_t *t)
 {
-        double a = trans->matrix[1][1] * trans->matrix[2][2] -
-            trans->matrix[1][2] * trans->matrix[2][1];
-        double b = trans->matrix[1][2] * trans->matrix[2][0] -
-            trans->matrix[2][2] * trans->matrix[1][0];
-        double c = trans->matrix[1][0] * trans->matrix[2][1] -
-            trans->matrix[1][1] * trans->matrix[2][0];
-        double d = trans->matrix[0][2] * trans->matrix[2][1] -
-            trans->matrix[0][1] * trans->matrix[2][2];
-        double e = trans->matrix[0][0] * trans->matrix[2][2] -
-            trans->matrix[0][2] * trans->matrix[2][0];
-        double f = trans->matrix[2][0] * trans->matrix[0][1] -
-            trans->matrix[0][0] * trans->matrix[2][1];
-        double g = trans->matrix[0][1] * trans->matrix[1][2] -
-            trans->matrix[0][2] * trans->matrix[1][1];
-        double h = trans->matrix[0][2] * trans->matrix[1][0] -
-            trans->matrix[0][0] * trans->matrix[1][2];
-        double k = trans->matrix[0][0] * trans->matrix[1][1] -
-            trans->matrix[0][1] * trans->matrix[1][0];
-        
-        double det = 1 / (a * trans->matrix[0][0] + b * trans->matrix[0][1] +
-            c * trans->matrix[0][2]);
-        
-        trans->matrix[0][0] = a * det;
-        trans->matrix[1][0] = b * det;
-        trans->matrix[2][0] = c * det;
-        
-        trans->matrix[0][1] = d * det;
-        trans->matrix[1][1] = e * det;
-        trans->matrix[2][1] = f * det;
-        
-        trans->matrix[0][2] = g * det;
-        trans->matrix[1][2] = h * det;
-        trans->matrix[2][2] = k * det;
+        double a = t->m[1][1] * t->m[2][2] - t->m[1][2] * t->m[2][1];
+        double b = t->m[1][2] * t->m[2][0] - t->m[2][2] * t->m[1][0];
+        double c = t->m[1][0] * t->m[2][1] - t->m[1][1] * t->m[2][0];
+        double d = t->m[0][2] * t->m[2][1] - t->m[0][1] * t->m[2][2];
+        double e = t->m[0][0] * t->m[2][2] - t->m[0][2] * t->m[2][0];
+        double f = t->m[2][0] * t->m[0][1] - t->m[0][0] * t->m[2][1];
+        double g = t->m[0][1] * t->m[1][2] - t->m[0][2] * t->m[1][1];
+        double h = t->m[0][2] * t->m[1][0] - t->m[0][0] * t->m[1][2];
+        double k = t->m[0][0] * t->m[1][1] - t->m[0][1] * t->m[1][0];
+
+        double det = t->m[0][0] * a + t->m[0][1] * b + t->m[0][2] * c;
+        det = 1 / det;
+
+        t->m[0][0] = a * det;   t->m[0][1] = d * det;   t->m[0][2] = g * det;
+        t->m[1][0] = b * det;   t->m[1][1] = e * det;   t->m[1][2] = h * det;
+        t->m[2][0] = c * det;   t->m[2][1] = f * det;   t->m[2][2] = k * det;
 }
 
-void transform_identity(transform_t *trans)
+void transform_identity(transform_t *t)
 {
-        trans->matrix[0][0] = 1;
-        trans->matrix[1][0] = 0;
-        trans->matrix[2][0] = 0;
-        
-        trans->matrix[0][1] = 0;
-        trans->matrix[1][1] = 1;
-        trans->matrix[2][1] = 0;
-        
-        trans->matrix[0][2] = 0;
-        trans->matrix[1][2] = 0;
-        trans->matrix[2][2] = 1;
+        t->m[0][0] = 1;   t->m[0][1] = 0;   t->m[0][2] = 0;
+        t->m[1][0] = 0;   t->m[1][1] = 1;   t->m[1][2] = 0;
+        t->m[2][0] = 0;   t->m[2][1] = 0;   t->m[2][2] = 1;
 }
 
-void transform_translate(transform_t *trans, double dx, double dy)
+void transform_translate(transform_t *t, double dx, double dy)
 {
         transform_t a;
-        
-        a.matrix[0][0] = 1;
-        a.matrix[1][0] = 0;
-        a.matrix[2][0] = 0;
-        
-        a.matrix[0][1] = 0;
-        a.matrix[1][1] = 1;
-        a.matrix[2][1] = 0;
-        
-        a.matrix[0][2] = dx;
-        a.matrix[1][2] = dy;
-        a.matrix[2][2] = 1;
-        
-        transform_t b = *trans;
-        
-        transform_product(trans, &a, &b);
+        a.m[0][0] = 1;   a.m[0][1] = 0;   a.m[0][2] = dx;
+        a.m[1][0] = 0;   a.m[1][1] = 1;   a.m[1][2] = dy;
+        a.m[2][0] = 0;   a.m[2][1] = 0;   a.m[2][2] = 1;
+
+        transform_t r;
+        transform_multiply(&r, &a, t);
+        *t = r;
 }
 
-void transform_scale(transform_t *trans, double qx, double qy)
+void transform_scale(transform_t *t, double qx, double qy)
 {
         transform_t a;
-        
-        a.matrix[0][0] = qx;
-        a.matrix[1][0] = 0;
-        a.matrix[2][0] = 0;
-        
-        a.matrix[0][1] = 0;
-        a.matrix[1][1] = qy;
-        a.matrix[2][1] = 0;
-        
-        a.matrix[0][2] = 0;
-        a.matrix[1][2] = 0;
-        a.matrix[2][2] = 1;
-        
-        transform_t b = *trans;
-        
-        transform_product(trans, &a, &b);
+        a.m[0][0] = qx;  a.m[0][1] = 0;   a.m[0][2] = 0;
+        a.m[1][0] = 0;   a.m[1][1] = qy;  a.m[1][2] = 0;
+        a.m[2][0] = 0;   a.m[2][1] = 0;   a.m[2][2] = 1;
+
+        transform_t r;
+        transform_multiply(&r, &a, t);
+        *t = r;
 }
 
-void transform_rotate(transform_t *trans, double angle)
+void transform_rotate(transform_t *t, double rad)
 {
+        double s, c;
+
+        // FIXME: temporary solution until there are trigonometric functions in libc
+
+        while (rad < 0) {
+                rad += (2 * PI);
+        }
+        
+        while (rad > (2 * PI)) {
+                rad -= (2 * PI);
+        }
+
+        if (rad >= 0 && rad < (PI / 4)) {
+                s = 0; c = 1;
+        } else if (rad >= (PI / 4) && rad < (3 * PI / 4)) {
+                s = 1; c = 0;
+        } else if (rad >= (3 * PI / 4) && rad < (5 * PI / 4)) {
+                s = 0; c = -1;
+        } else if (rad >= (5 * PI / 4) && rad < (7 * PI / 4)) {
+                s = -1; c = 0;
+        } else {
+                s = 0; c = 1;
+        }
+
         transform_t a;
-        
-        a.matrix[0][0] = cos(angle);
-        a.matrix[1][0] = sin(angle);
-        a.matrix[2][0] = 0;
-        
-        a.matrix[0][1] = -sin(angle);
-        a.matrix[1][1] = cos(angle);
-        a.matrix[2][1] = 0;
-        
-        a.matrix[0][2] = 0;
-        a.matrix[1][2] = 0;
-        a.matrix[2][2] = 1;
-        
-        transform_t b = *trans;
-        
-        transform_product(trans, &a, &b);
+        a.m[0][0] = c;   a.m[0][1] = -s;  a.m[0][2] = 0;
+        a.m[1][0] = s;   a.m[1][1] = c;   a.m[1][2] = 0;
+        a.m[2][0] = 0;   a.m[2][1] = 0;   a.m[2][2] = 1;
+
+        transform_t r;
+        transform_multiply(&r, &a, t);
+        *t = r;
 }
 
-bool transform_is_fast(transform_t *trans)
+bool transform_is_fast(transform_t *t)
 {
-        return ((trans->matrix[0][0] == 1) && (trans->matrix[0][1] == 0) &&
-            (trans->matrix[1][0] == 0) && (trans->matrix[1][1] == 1) &&
-            ((trans->matrix[0][2] - trunc(trans->matrix[0][2])) == 0.0) &&
-            ((trans->matrix[1][2] - trunc(trans->matrix[1][2])) == 0.0));
+        return (t->m[0][0] == 1) && (t->m[0][1] == 0)
+            && (t->m[1][0] == 0) && (t->m[1][1] == 1)
+            && ((t->m[0][2] - ((long) t->m[0][2])) == 0.0)
+            && ((t->m[1][2] - ((long) t->m[1][2])) == 0.0);
 }
 
-void transform_apply_linear(const transform_t *trans, double *x, double *y)
+void transform_apply_linear(const transform_t *t, double *x, double *y)
 {
-        double old_x = *x;
-        double old_y = *y;
-        
-        *x = old_x * trans->matrix[0][0] + old_y * trans->matrix[0][1];
-        *y = old_x * trans->matrix[1][0] + old_y * trans->matrix[1][1];
+        double x_ = *x;
+        double y_ = *y;
+        *x = x_ * t->m[0][0] + y_ * t->m[0][1];
+        *y = x_ * t->m[1][0] + y_ * t->m[1][1];
 }
 
-void transform_apply_affine(const transform_t *trans, double *x, double *y)
+void transform_apply_affine(const transform_t *t, double *x, double *y)
 {
-        double old_x = *x;
-        double old_y = *y;
-        
-        *x = old_x * trans->matrix[0][0] + old_y * trans->matrix[0][1] +
-            trans->matrix[0][2];
-        *y = old_x * trans->matrix[1][0] + old_y * trans->matrix[1][1] +
-            trans->matrix[1][2];
+        double x_ = *x;
+        double y_ = *y;
+        *x = x_ * t->m[0][0] + y_ * t->m[0][1] + t->m[0][2];
+        *y = x_ * t->m[1][0] + y_ * t->m[1][1] + t->m[1][2];
 }