bit of documentation

[freeglut] / progs / demos / shapes / glmatrix.c

diff --git a/progs/demos/shapes/glmatrix.c b/progs/demos/shapes/glmatrix.c
index 3d1b77e..961bf7c 100644 (file)
--- a/progs/demos/shapes/glmatrix.c
+++ b/progs/demos/shapes/glmatrix.c
@@ -171,6 +171,7 @@ void glu_perspective(float vfov, float aspect, float near, float far)
     gl_frustum(-aspect * x, aspect * x, -x, x, near, far);\r
 }\r
 \r
+/* return the matrix (16 elements, 4x4 matrix, row-major order */\r
 float* get_matrix(int mm)\r
 {\r
     int idx = MMODE_IDX(mm);\r
@@ -182,6 +183,10 @@ float* get_matrix(int mm)
 #define M3(i, j)       ((i * 3) + j)\r
 static float inv_transpose_result[9];\r
 \r
+/* return the inverse transpose of the left-upper 3x3 of a matrix\r
+   The returned pointer is only valid until the next time this function is\r
+   called, so make a deep copy when you want to keep it around.\r
+ */\r
 float* get_inv_transpose_3x3(int mm)\r
 {\r
     int idx = MMODE_IDX(mm);\r
@@ -207,48 +212,3 @@ float* get_inv_transpose_3x3(int mm)
 \r
     return inv_transpose_result;\r
 }\r
-\r
-\r
-#if 0\r
-void gl_apply_xform(unsigned int prog)\r
-{\r
-    int loc, mvidx, pidx, tidx, mvtop, ptop, ttop;\r
-\r
-    mvidx = MMODE_IDX(GL_MODELVIEW);\r
-    pidx = MMODE_IDX(GL_PROJECTION);\r
-    tidx = MMODE_IDX(GL_TEXTURE);\r
-\r
-    mvtop = stack_top[mvidx];\r
-    ptop = stack_top[pidx];\r
-    ttop = stack_top[tidx];\r
-\r
-    assert(prog);\r
-\r
-    if((loc = glGetUniformLocation(prog, "matrix_modelview")) != -1) {\r
-        glUniformMatrix4fv(loc, 1, 0, mat_stack[mvidx][mvtop]);\r
-    }\r
-\r
-    if((loc = glGetUniformLocation(prog, "matrix_projection")) != -1) {\r
-        glUniformMatrix4fv(loc, 1, 0, mat_stack[pidx][ptop]);\r
-    }\r
-\r
-    if((loc = glGetUniformLocation(prog, "matrix_texture")) != -1) {\r
-        glUniformMatrix4fv(loc, 1, 0, mat_stack[tidx][ttop]);\r
-    }\r
-\r
-    if((loc = glGetUniformLocation(prog, "matrix_normal")) != -1) {\r
-        float nmat[9];\r
-\r
-        nmat[0] = mat_stack[mvidx][mvtop][0];\r
-        nmat[1] = mat_stack[mvidx][mvtop][1];\r
-        nmat[2] = mat_stack[mvidx][mvtop][2];\r
-        nmat[3] = mat_stack[mvidx][mvtop][4];\r
-        nmat[4] = mat_stack[mvidx][mvtop][5];\r
-        nmat[5] = mat_stack[mvidx][mvtop][6];\r
-        nmat[6] = mat_stack[mvidx][mvtop][8];\r
-        nmat[7] = mat_stack[mvidx][mvtop][9];\r
-        nmat[8] = mat_stack[mvidx][mvtop][10];\r
-        glUniformMatrix3fv(loc, 1, 0, nmat);\r
-    }\r
-}\r
-#endif\r