X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=progs%2Fdemos%2Fshapes%2Fglmatrix.c;h=485e324d8a2f4841b0a90762676063e28fee7a93;hb=b304f6f9002f17cc263e06641a92f19ffbfaf062;hp=3d1b77e65d4442797335b3741a45cfd2d3b5788a;hpb=8a58cc57b97a1aa188018d987671ed565031874d;p=freeglut

diff --git a/progs/demos/shapes/glmatrix.c b/progs/demos/shapes/glmatrix.c
index 3d1b77e..485e324 100644
--- a/progs/demos/shapes/glmatrix.c
+++ b/progs/demos/shapes/glmatrix.c
@@ -3,6 +3,10 @@
 #include <math.h>
 #include "glmatrix.h"
 
+#ifndef M_PI
+#define M_PI	3.141592653589793
+#endif
+
 #define MMODE_IDX(x)	((x) - GL_MODELVIEW)
 #define MAT_STACK_SIZE	32
 #define MAT_IDENT	{1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1}
@@ -114,17 +118,17 @@ void gl_scalef(float x, float y, float z)
     gl_mult_matrixf(mat);
 }
 
-void gl_ortho(float left, float right, float bottom, float top, float near, float far)
+void gl_ortho(float left, float right, float bottom, float top, float znear, float zfar)
 {
     float mat[] = MAT_IDENT;
 
     float dx = right - left;
     float dy = top - bottom;
-    float dz = far - near;
+    float dz = zfar - znear;
 
     float tx = -(right + left) / dx;
     float ty = -(top + bottom) / dy;
-    float tz = -(far + near) / dz;
+    float tz = -(zfar + znear) / dz;
 
     float sx = 2.f / dx;
     float sy = 2.f / dy;
@@ -140,37 +144,39 @@ void gl_ortho(float left, float right, float bottom, float top, float near, floa
     gl_mult_matrixf(mat);
 }
 
-void gl_frustum(float left, float right, float bottom, float top, float near, float far)
+void gl_frustum(float left, float right, float bottom, float top, float znear, float zfar)
 {
     float mat[] = MAT_IDENT;
 
     float dx = right - left;
     float dy = top - bottom;
-    float dz = far - near;
+    float dz = zfar - znear;
 
     float a = (right + left) / dx;
     float b = (top + bottom) / dy;
-    float c = -(far + near) / dz;
-    float d = -2.f * far * near / dz;
+    float c = -(zfar + znear) / dz;
+    float d = -2.f * zfar * znear / dz;
 
-    mat[0] = 2.f * near / dx;
-    mat[5] = 2.f * near / dy;
+    mat[0] = 2.f * znear / dx;
+    mat[5] = 2.f * znear / dy;
     mat[8] = a;
     mat[9] = b;
     mat[10] = c;
     mat[11] = -1.f;
     mat[14] = d;
+    mat[15] = 0;
 
     gl_mult_matrixf(mat);
 }
 
-void glu_perspective(float vfov, float aspect, float near, float far)
+void glu_perspective(float vfov, float aspect, float znear, float zfar)
 {
     float vfov_rad = (float)M_PI * vfov / 180.f;
-    float x = near * (float)tan(vfov_rad / 2.f);
-    gl_frustum(-aspect * x, aspect * x, -x, x, near, far);
+    float x = znear * (float)tan(vfov_rad / 2.f);
+    gl_frustum(-aspect * x, aspect * x, -x, x, znear, zfar);
 }
 
+/* return the matrix (16 elements, 4x4 matrix, row-major order */
 float* get_matrix(int mm)
 {
     int idx = MMODE_IDX(mm);
@@ -182,6 +188,10 @@ float* get_matrix(int mm)
 #define M3(i, j)	((i * 3) + j)
 static float inv_transpose_result[9];
 
+/* return the inverse transpose of the left-upper 3x3 of a matrix
+   The returned pointer is only valid until the next time this function is
+   called, so make a deep copy when you want to keep it around.
+ */
 float* get_inv_transpose_3x3(int mm)
 {
     int idx = MMODE_IDX(mm);
@@ -207,48 +217,3 @@ float* get_inv_transpose_3x3(int mm)
 
     return inv_transpose_result;
 }
-
-
-#if 0
-void gl_apply_xform(unsigned int prog)
-{
-    int loc, mvidx, pidx, tidx, mvtop, ptop, ttop;
-
-    mvidx = MMODE_IDX(GL_MODELVIEW);
-    pidx = MMODE_IDX(GL_PROJECTION);
-    tidx = MMODE_IDX(GL_TEXTURE);
-
-    mvtop = stack_top[mvidx];
-    ptop = stack_top[pidx];
-    ttop = stack_top[tidx];
-
-    assert(prog);
-
-    if((loc = glGetUniformLocation(prog, "matrix_modelview")) != -1) {
-        glUniformMatrix4fv(loc, 1, 0, mat_stack[mvidx][mvtop]);
-    }
-
-    if((loc = glGetUniformLocation(prog, "matrix_projection")) != -1) {
-        glUniformMatrix4fv(loc, 1, 0, mat_stack[pidx][ptop]);
-    }
-
-    if((loc = glGetUniformLocation(prog, "matrix_texture")) != -1) {
-        glUniformMatrix4fv(loc, 1, 0, mat_stack[tidx][ttop]);
-    }
-
-    if((loc = glGetUniformLocation(prog, "matrix_normal")) != -1) {
-        float nmat[9];
-
-        nmat[0] = mat_stack[mvidx][mvtop][0];
-        nmat[1] = mat_stack[mvidx][mvtop][1];
-        nmat[2] = mat_stack[mvidx][mvtop][2];
-        nmat[3] = mat_stack[mvidx][mvtop][4];
-        nmat[4] = mat_stack[mvidx][mvtop][5];
-        nmat[5] = mat_stack[mvidx][mvtop][6];
-        nmat[6] = mat_stack[mvidx][mvtop][8];
-        nmat[7] = mat_stack[mvidx][mvtop][9];
-        nmat[8] = mat_stack[mvidx][mvtop][10];
-        glUniformMatrix3fv(loc, 1, 0, nmat);
-    }
-}
-#endif