Merge pull request #410 from EasyIP2023/bugfix/mat4x2-multiplication

mat4x2: fix multiplication functions

docs/source/mat4x2.rst

@@ -23,6 +23,15 @@ Functions:
 #. :c:func:`glm_mat4x2_transpose`
 #. :c:func:`glm_mat4x2_scale`
 
+Represented
+~~~~~~~~~~~
+
+.. csv-table:: mat4x2
+   :header: "", "column 1", "column 2", "column 3", "column4"
+
+   "row 1", "m00", "m10", "m20", "m30"
+   "row 2", "m01", "m11", "m21", "m31"
+
 Functions documentation
 ~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -51,28 +60,70 @@ Functions documentation
       | *[in]*  **src**  pointer to an array of floats
       | *[out]* **dest** destination matrix4x2
 
-.. c:function:: void glm_mat4x2_mul(mat4x2 m1, mat2x4 m2, mat4 dest)
+.. c:function:: void glm_mat4x2_mul(mat4x2 m1, mat2x4 m2, mat2 dest)
 
     multiply m1 and m2 to dest
 
     .. code-block:: c
 
-       glm_mat4x2_mul(mat4x2, mat2x4, mat4);
+       glm_mat4x2_mul(mat4x2, mat2x4, mat2);
 
     Parameters:
       | *[in]*  **m1**    left matrix (mat4x2)
       | *[in]*  **m2**    right matrix (mat2x4)
-      | *[out]* **dest**  destination matrix (mat4)
+      | *[out]* **dest**  destination matrix (mat2)
+
+    .. csv-table:: mat4x2
+        :header: "", "column 1", "column 2", "column 3", "column 4"
+
+        "row 1", "a00", "a10", "a20", "a30"
+        "row 2", "a01", "a11", "a21", "a31"
+
+    .. csv-table:: mat2x4
+        :header: "", "column 1", "column 2"
+
+        "row 1", "b00", "b10"
+        "row 2", "b01", "b11"
+        "row 3", "b02", "b12"
+        "row 4", "b03", "b13"
+
+    .. csv-table:: mat2x2
+        :header: "", "column 1", "column 2"
 
-.. c:function:: void glm_mat4x2_mulv(mat4x2 m, vec2 v, vec4 dest)
+        "row 1", "a00 * b00 + a10 * b01 + a20 * b02 + a30 * b03", "a00 * b10 + a10 * b11 + a20 * b12 + a30 * b13"
+        "row 2", "a01 * b00 + a11 * b01 + a21 * b02 + a31 * b03", "a01 * b10 + a11 * b11 + a21 * b12 + a31 * b13"
 
-    multiply mat4x2 with vec2 (column vector) and store in dest vector
+.. c:function:: void glm_mat4x2_mulv(mat4x2 m, vec4 v, vec2 dest)
+
+    multiply mat4x2 with vec4 (column vector) and store in dest vector
 
     Parameters:
       | *[in]*  **m**     mat4x2 (left)
-      | *[in]*  **v**     vec2 (right, column vector)
+      | *[in]*  **v**     vec4 (right, column vector)
       | *[out]* **dest**  destination (result, column vector)
 
+    .. csv-table:: mat4x2
+        :header: "", "column 1", "column 2", "column 3"
+
+        "row 1", "m00", "m10", "m20"
+        "row 2", "m01", "m11", "m21"
+        "row 3", "m02", "m12", "m22"
+        "row 4", "m03", "m13", "m23"
+
+    .. csv-table:: column vec4 (1x4)
+        :header: "", "column 1"
+
+        "row 1", "v0"
+        "row 2", "v1"
+        "row 3", "v2"
+        "row 4", "v3"
+
+    .. csv-table:: column vec2 (1x2)
+        :header: "", "column 1"
+
+        "row 1", "m00 * v0 + m10 * v1 + m20 * v2 + m30 * v3"
+        "row 2", "m01 * v0 + m11 * v1 + m21 * v2 + m31 * v3"
+
 .. c:function:: void glm_mat4x2_transpose(mat4x2 m, mat2x4 dest)
 
     transpose matrix and store in dest

include/cglm/call/mat4x2.h

@@ -27,11 +27,11 @@ glmc_mat4x2_make(const float * __restrict src, mat4x2 dest);
 
 CGLM_EXPORT
 void
-glmc_mat4x2_mul(mat4x2 m1, mat2x4 m2, mat4 dest);
+glmc_mat4x2_mul(mat4x2 m1, mat2x4 m2, mat2 dest);
 
 CGLM_EXPORT
 void
-glmc_mat4x2_mulv(mat4x2 m, vec2 v, vec4 dest);
+glmc_mat4x2_mulv(mat4x2 m, vec4 v, vec2 dest);
 
 CGLM_EXPORT
 void

include/cglm/mat4x2.h

@@ -14,8 +14,8 @@
    CGLM_INLINE void glm_mat4x2_copy(mat4x2 mat, mat4x2 dest);
    CGLM_INLINE void glm_mat4x2_zero(mat4x2 mat);
    CGLM_INLINE void glm_mat4x2_make(const float * __restrict src, mat4x2 dest);
-   CGLM_INLINE void glm_mat4x2_mul(mat4x2 m1, mat2x4 m2, mat4 dest);
-   CGLM_INLINE void glm_mat4x2_mulv(mat4x2 m, vec2 v, vec4 dest);
+   CGLM_INLINE void glm_mat4x2_mul(mat4x2 m1, mat2x4 m2, mat2 dest);
+   CGLM_INLINE void glm_mat4x2_mulv(mat4x2 m, vec4 v, vec2 dest);
    CGLM_INLINE void glm_mat4x2_transpose(mat4x2 m, mat2x4 dest);
    CGLM_INLINE void glm_mat4x2_scale(mat4x2 m, float s);
  */
@@ -90,16 +90,16 @@ glm_mat4x2_make(const float * __restrict src, mat4x2 dest) {
  * @brief multiply m1 and m2 to dest
  *
  * @code
- * glm_mat4x2_mul(mat4x2, mat2x4, mat4);
+ * glm_mat4x2_mul(mat4x2, mat2x4, mat2);
  * @endcode
  *
  * @param[in]  m1   left matrix (mat4x2)
  * @param[in]  m2   right matrix (mat2x4)
- * @param[out] dest destination matrix (mat4)
+ * @param[out] dest destination matrix (mat2)
  */
 CGLM_INLINE
 void
-glm_mat4x2_mul(mat4x2 m1, mat2x4 m2, mat4 dest) {
+glm_mat4x2_mul(mat4x2 m1, mat2x4 m2, mat2 dest) {
   float a00 = m1[0][0], a01 = m1[0][1],
         a10 = m1[1][0], a11 = m1[1][1],
         a20 = m1[2][0], a21 = m1[2][1],
@@ -108,43 +108,27 @@ glm_mat4x2_mul(mat4x2 m1, mat2x4 m2, mat4 dest) {
         b00 = m2[0][0], b01 = m2[0][1], b02 = m2[0][2], b03 = m2[0][3],
         b10 = m2[1][0], b11 = m2[1][1], b12 = m2[1][2], b13 = m2[1][3];
 
-  dest[0][0] = a00 * b00 + a01 * b10;
-  dest[0][1] = a00 * b01 + a01 * b11;
-  dest[0][2] = a00 * b02 + a01 * b12;
-  dest[0][3] = a00 * b03 + a01 * b13;
-
-  dest[1][0] = a10 * b00 + a11 * b10;
-  dest[1][1] = a10 * b01 + a11 * b11;
-  dest[1][2] = a10 * b02 + a11 * b12;
-  dest[1][3] = a10 * b03 + a11 * b13;
-
-  dest[2][0] = a20 * b00 + a21 * b10;
-  dest[2][1] = a20 * b01 + a21 * b11;
-  dest[2][2] = a20 * b02 + a21 * b12;
-  dest[2][3] = a20 * b03 + a21 * b13;
-
-  dest[3][0] = a30 * b00 + a31 * b10;
-  dest[3][1] = a30 * b01 + a31 * b11;
-  dest[3][2] = a30 * b02 + a31 * b12;
-  dest[3][3] = a30 * b03 + a31 * b13;
+  dest[0][0] = a00 * b00 + a10 * b01 + a20 * b02 + a30 * b03;
+  dest[0][1] = a01 * b00 + a11 * b01 + a21 * b02 + a31 * b03;
+
+  dest[1][0] = a00 * b10 + a10 * b11 + a20 * b12 + a30 * b13;
+  dest[1][1] = a01 * b10 + a11 * b11 + a21 * b12 + a31 * b13;
 }
 
 /*!
- * @brief multiply matrix with column vector and store in dest vector
+ * @brief multiply matrix with column vector and store in dest column vector
  *
  * @param[in]  m    matrix (left)
  * @param[in]  v    vector (right, column vector)
  * @param[out] dest result vector
  */
 CGLM_INLINE
 void
-glm_mat4x2_mulv(mat4x2 m, vec2 v, vec4 dest) {
-  float v0 = v[0], v1 = v[1];
+glm_mat4x2_mulv(mat4x2 m, vec4 v, vec2 dest) {
+  float v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
 
-  dest[0] = m[0][0] * v0 + m[0][1] * v1;
-  dest[1] = m[1][0] * v0 + m[1][1] * v1;
-  dest[2] = m[2][0] * v0 + m[2][1] * v1;
-  dest[3] = m[3][0] * v0 + m[3][1] * v1;
+  dest[0] = m[0][0] * v0 + m[1][0] * v1 + m[2][0] * v2 + m[3][0] * v3;
+  dest[1] = m[0][1] * v0 + m[1][1] * v1 + m[2][1] * v2 + m[3][1] * v3;
 }
 
 /*!

include/cglm/struct/mat4x2.h

@@ -13,8 +13,8 @@
  Functions:
    CGLM_INLINE mat4x2s glms_mat4x2_zero(void);
    CGLM_INLINE mat4x2s glms_mat4x2_make(const float * __restrict src);
-   CGLM_INLINE mat4s   glms_mat4x2_mul(mat4x2s m1, mat2x4s m2);
-   CGLM_INLINE vec4s   glms_mat4x2_mulv(mat4x2s m, vec2s v);
+   CGLM_INLINE mat2s   glms_mat4x2_mul(mat4x2s m1, mat2x4s m2);
+   CGLM_INLINE vec2s   glms_mat4x2_mulv(mat4x2s m, vec4s v);
    CGLM_INLINE mat2x4s glms_mat4x2_transpose(mat4x2s m);
    CGLM_INLINE mat4x2s glms_mat4x2_scale(mat4x2s m, float s);
  */
@@ -71,27 +71,27 @@ glms_mat4x2_(make)(const float * __restrict src) {
  *
  * @param[in]  m1   left matrix (mat4x2s)
  * @param[in]  m2   right matrix (mat2x4s)
- * @returns destination matrix (mat4s)
+ * @returns destination matrix (mat2s)
  */
 CGLM_INLINE
-mat4s
+mat2s
 glms_mat4x2_(mul)(mat4x2s m1, mat2x4s m2) {
-  mat4s r;
+  mat2s r;
   glm_mat4x2_mul(m1.raw, m2.raw, r.raw);
   return r;
 }
 
 /*!
- * @brief multiply matrix with column vector and store in dest vector
+ * @brief multiply matrix with column vector and store in dest column vector
  *
  * @param[in]  m    matrix (left)
  * @param[in]  v    vector (right, column vector)
- * @param[out] dest result vector
+ * @returns destination vector (vec2s)
  */
 CGLM_INLINE
-vec4s
-glms_mat4x2_(mulv)(mat4x2s m, vec2s v) {
-  vec4s r;
+vec2s
+glms_mat4x2_(mulv)(mat4x2s m, vec4s v) {
+  vec2s r;
   glm_mat4x2_mulv(m.raw, v.raw, r.raw);
   return r;
 }

src/mat4x2.c

@@ -28,13 +28,13 @@ glmc_mat4x2_make(const float * __restrict src, mat4x2 dest) {
 
 CGLM_EXPORT
 void
-glmc_mat4x2_mul(mat4x2 m1, mat2x4 m2, mat4 dest) {
+glmc_mat4x2_mul(mat4x2 m1, mat2x4 m2, mat2 dest) {
   glm_mat4x2_mul(m1, m2, dest);
 }
 
 CGLM_EXPORT
 void
-glmc_mat4x2_mulv(mat4x2 m, vec2 v, vec4 dest) {
+glmc_mat4x2_mulv(mat4x2 m, vec4 v, vec2 dest) {
   glm_mat4x2_mulv(m, v, dest);
 }
 

test/src/test_mat4x2.h

@@ -87,40 +87,40 @@ TEST_IMPL(GLM_PREFIX, mat4x2_mul) {
   mat4x2 m1 = GLM_MAT4X2_ZERO_INIT;
   mat2x4 m2 = GLM_MAT2X4_ZERO_INIT;
 
-  mat4 m3 = GLM_MAT4_ZERO_INIT;
-  mat4 m4 = GLM_MAT4_ZERO_INIT;
+  mat2 m3 = GLM_MAT2_ZERO_INIT;
+  mat2 m4 = GLM_MAT2_ZERO_INIT;
 
-  int i, j, k;
+  int c, r, k;
 
   test_rand_mat4x2(m1);
   test_rand_mat2x4(m2);
 
-  for (i = 0; i < 4; i++) {
-    for (j = 0; j < 4; j++) {
-      for (k = 0; k < 2; k++) {
-        m4[i][j] += m1[i][k] * m2[k][j];
+  for (r = 0; r < 2; r++) {
+    for (c = 0; c < 2; c++) {
+      for (k = 0; k < 4; k++) {
+	m4[c][r] += m1[k][r] * m2[c][k];
       }
     }
   }
 
   GLM(mat4x2_mul)(m1, m2, m3);
-  ASSERTIFY(test_assert_mat4_eq(m3, m4))
+  ASSERTIFY(test_assert_mat2_eq(m3, m4))
 
   TEST_SUCCESS
 }
 
 TEST_IMPL(GLM_PREFIX, mat4x2_mulv) {
   mat4x2 mat = A_MATRIX4X2;
-  vec2 v = {11.0f, 21.0f};
+  vec4 v = {11.0f, 21.0f, 31.0f, 41.0f};
 
   int  i;
-  vec4 dest;
+  vec2 dest;
   float res = 0.0;
 
   GLM(mat4x2_mulv)(mat, v, dest);
 
-  for (i = 0; i < 4; i++) {
-    res = mat[i][0] * v[0] + mat[i][1] * v[1];
+  for (i = 0; i < 2; i++) {
+    res = mat[0][i] * v[0] + mat[1][i] * v[1] + mat[2][i] * v[2] + mat[3][i] * v[3];
     ASSERT(test_eq(dest[i], res))
   }