From: John Tsiombikas <nuclear@member.fsf.org>
Date: Thu, 6 Aug 2020 22:46:44 +0000 (+0300)
Subject: added Utah teapot
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=commitdiff_plain;h=78bc758ea19b66116da12c65f02a96754db51c99;p=miniglut

added Utah teapot
---

diff --git a/miniglut.c b/miniglut.c
index b098651..631aac4 100644
--- a/miniglut.c
+++ b/miniglut.c
@@ -2095,10 +2095,323 @@ void glutWireTorus(float inner_rad, float outer_rad, int sides, int rings)
 	glPopAttrib();
 }
 
+#define NUM_TEAPOT_INDICES	(sizeof teapot_index / sizeof *teapot_index)
+#define NUM_TEAPOT_VERTS	(sizeof teapot_verts / sizeof *teapot_verts)
+
+#define NUM_TEAPOT_PATCHES	(NUM_TEAPOT_INDICES / 16)
+
+#define PATCH_SUBDIV	7
+
+static float teapot_part_flip[] = {
+	1, 1, 1, 1,			/* rim flip */
+	1, 1, 1, 1,			/* body1 flip */
+	1, 1, 1, 1,			/* body2 flip */
+	1, 1, 1, 1,			/* lid patch 1 flip */
+	1, 1, 1, 1,			/* lid patch 2 flip */
+	1, -1,				/* handle 1 flip */
+	1, -1,				/* handle 2 flip */
+	1, -1,				/* spout 1 flip */
+	1, -1,				/* spout 2 flip */
+	1, 1, 1, 1			/* bottom flip */
+};
+
+static float teapot_part_rot[] = {
+	0, 90, 180, 270,	/* rim rotations */
+	0, 90, 180, 270,	/* body patch 1 rotations */
+	0, 90, 180, 270,	/* body patch 2 rotations */
+	0, 90, 180, 270,	/* lid patch 1 rotations */
+	0, 90, 180, 270,	/* lid patch 2 rotations */
+	0, 0,				/* handle 1 rotations */
+	0, 0,				/* handle 2 rotations */
+	0, 0,				/* spout 1 rotations */
+	0, 0,				/* spout 2 rotations */
+	0, 90, 180, 270		/* bottom rotations */
+};
+
+
+static int teapot_index[] = {
+	/* rim */
+	102, 103, 104, 105, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+	102, 103, 104, 105, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+	102, 103, 104, 105, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+	102, 103, 104, 105, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
+	/* body1 */
+	12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
+	12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
+	12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
+	12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
+	/* body 2 */
+	24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+	24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+	24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+	24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
+	/* lid 1 */
+	96, 96, 96, 96, 97, 98, 99, 100, 101, 101, 101, 101, 0,  1,  2, 3,
+	96, 96, 96, 96, 97, 98, 99, 100, 101, 101, 101, 101, 0,  1,  2, 3,
+	96, 96, 96, 96, 97, 98, 99, 100, 101, 101, 101, 101, 0,  1,  2, 3,
+	96, 96, 96, 96, 97, 98, 99, 100, 101, 101, 101, 101, 0,  1,  2, 3,
+	/* lid 2 */
+	0,  1,  2,  3, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117,
+	0,  1,  2,  3, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117,
+	0,  1,  2,  3, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117,
+	0,  1,  2,  3, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117,
+	/* handle 1 */
+	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56,
+	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56,
+	/* handle 2 */
+	53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 28, 65, 66, 67,
+	53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 28, 65, 66, 67,
+	/* spout 1 */
+	68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83,
+	68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83,
+	/* spout 2 */
+	80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
+	80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95,
+	/* bottom */
+	118, 118, 118, 118, 124, 122, 119, 121, 123, 126, 125, 120, 40, 39, 38, 37,
+	118, 118, 118, 118, 124, 122, 119, 121, 123, 126, 125, 120, 40, 39, 38, 37,
+	118, 118, 118, 118, 124, 122, 119, 121, 123, 126, 125, 120, 40, 39, 38, 37,
+	118, 118, 118, 118, 124, 122, 119, 121, 123, 126, 125, 120, 40, 39, 38, 37
+};
+
+
+static float teapot_verts[][3] = {
+	{  0.2000,  0.0000, 2.70000 }, {  0.2000, -0.1120, 2.70000 },
+	{  0.1120, -0.2000, 2.70000 }, {  0.0000, -0.2000, 2.70000 },
+	{  1.3375,  0.0000, 2.53125 }, {  1.3375, -0.7490, 2.53125 },
+	{  0.7490, -1.3375, 2.53125 }, {  0.0000, -1.3375, 2.53125 },
+	{  1.4375,  0.0000, 2.53125 }, {  1.4375, -0.8050, 2.53125 },
+	{  0.8050, -1.4375, 2.53125 }, {  0.0000, -1.4375, 2.53125 },
+	{  1.5000,  0.0000, 2.40000 }, {  1.5000, -0.8400, 2.40000 },
+	{  0.8400, -1.5000, 2.40000 }, {  0.0000, -1.5000, 2.40000 },
+	{  1.7500,  0.0000, 1.87500 }, {  1.7500, -0.9800, 1.87500 },
+	{  0.9800, -1.7500, 1.87500 }, {  0.0000, -1.7500, 1.87500 },
+	{  2.0000,  0.0000, 1.35000 }, {  2.0000, -1.1200, 1.35000 },
+	{  1.1200, -2.0000, 1.35000 }, {  0.0000, -2.0000, 1.35000 },
+	{  2.0000,  0.0000, 0.90000 }, {  2.0000, -1.1200, 0.90000 },
+	{  1.1200, -2.0000, 0.90000 }, {  0.0000, -2.0000, 0.90000 },
+	{ -2.0000,  0.0000, 0.90000 }, {  2.0000,  0.0000, 0.45000 },
+	{  2.0000, -1.1200, 0.45000 }, {  1.1200, -2.0000, 0.45000 },
+	{  0.0000, -2.0000, 0.45000 }, {  1.5000,  0.0000, 0.22500 },
+	{  1.5000, -0.8400, 0.22500 }, {  0.8400, -1.5000, 0.22500 },
+	{  0.0000, -1.5000, 0.22500 }, {  1.5000,  0.0000, 0.15000 },
+	{  1.5000, -0.8400, 0.15000 }, {  0.8400, -1.5000, 0.15000 },
+	{  0.0000, -1.5000, 0.15000 }, { -1.6000,  0.0000, 2.02500 },
+	{ -1.6000, -0.3000, 2.02500 }, { -1.5000, -0.3000, 2.25000 },
+	{ -1.5000,  0.0000, 2.25000 }, { -2.3000,  0.0000, 2.02500 },
+	{ -2.3000, -0.3000, 2.02500 }, { -2.5000, -0.3000, 2.25000 },
+	{ -2.5000,  0.0000, 2.25000 }, { -2.7000,  0.0000, 2.02500 },
+	{ -2.7000, -0.3000, 2.02500 }, { -3.0000, -0.3000, 2.25000 },
+	{ -3.0000,  0.0000, 2.25000 }, { -2.7000,  0.0000, 1.80000 },
+	{ -2.7000, -0.3000, 1.80000 }, { -3.0000, -0.3000, 1.80000 },
+	{ -3.0000,  0.0000, 1.80000 }, { -2.7000,  0.0000, 1.57500 },
+	{ -2.7000, -0.3000, 1.57500 }, { -3.0000, -0.3000, 1.35000 },
+	{ -3.0000,  0.0000, 1.35000 }, { -2.5000,  0.0000, 1.12500 },
+	{ -2.5000, -0.3000, 1.12500 }, { -2.6500, -0.3000, 0.93750 },
+	{ -2.6500,  0.0000, 0.93750 }, { -2.0000, -0.3000, 0.90000 },
+	{ -1.9000, -0.3000, 0.60000 }, { -1.9000,  0.0000, 0.60000 },
+	{  1.7000,  0.0000, 1.42500 }, {  1.7000, -0.6600, 1.42500 },
+	{  1.7000, -0.6600, 0.60000 }, {  1.7000,  0.0000, 0.60000 },
+	{  2.6000,  0.0000, 1.42500 }, {  2.6000, -0.6600, 1.42500 },
+	{  3.1000, -0.6600, 0.82500 }, {  3.1000,  0.0000, 0.82500 },
+	{  2.3000,  0.0000, 2.10000 }, {  2.3000, -0.2500, 2.10000 },
+	{  2.4000, -0.2500, 2.02500 }, {  2.4000,  0.0000, 2.02500 },
+	{  2.7000,  0.0000, 2.40000 }, {  2.7000, -0.2500, 2.40000 },
+	{  3.3000, -0.2500, 2.40000 }, {  3.3000,  0.0000, 2.40000 },
+	{  2.8000,  0.0000, 2.47500 }, {  2.8000, -0.2500, 2.47500 },
+	{  3.5250, -0.2500, 2.49375 }, {  3.5250,  0.0000, 2.49375 },
+	{  2.9000,  0.0000, 2.47500 }, {  2.9000, -0.1500, 2.47500 },
+	{  3.4500, -0.1500, 2.51250 }, {  3.4500,  0.0000, 2.51250 },
+	{  2.8000,  0.0000, 2.40000 }, {  2.8000, -0.1500, 2.40000 },
+	{  3.2000, -0.1500, 2.40000 }, {  3.2000,  0.0000, 2.40000 },
+	{  0.0000,  0.0000, 3.15000 }, {  0.8000,  0.0000, 3.15000 },
+	{  0.8000, -0.4500, 3.15000 }, {  0.4500, -0.8000, 3.15000 },
+	{  0.0000, -0.8000, 3.15000 }, {  0.0000,  0.0000, 2.85000 },
+	{  1.4000,  0.0000, 2.40000 }, {  1.4000, -0.7840, 2.40000 },
+	{  0.7840, -1.4000, 2.40000 }, {  0.0000, -1.4000, 2.40000 },
+	{  0.4000,  0.0000, 2.55000 }, {  0.4000, -0.2240, 2.55000 },
+	{  0.2240, -0.4000, 2.55000 }, {  0.0000, -0.4000, 2.55000 },
+	{  1.3000,  0.0000, 2.55000 }, {  1.3000, -0.7280, 2.55000 },
+	{  0.7280, -1.3000, 2.55000 }, {  0.0000, -1.3000, 2.55000 },
+	{  1.3000,  0.0000, 2.40000 }, {  1.3000, -0.7280, 2.40000 },
+	{  0.7280, -1.3000, 2.40000 }, {  0.0000, -1.3000, 2.40000 },
+	{  0.0000,  0.0000, 0.00000 }, {  1.4250, -0.7980, 0.00000 },
+	{  1.5000,  0.0000, 0.07500 }, {  1.4250,  0.0000, 0.00000 },
+	{  0.7980, -1.4250, 0.00000 }, {  0.0000, -1.5000, 0.07500 },
+	{  0.0000, -1.4250, 0.00000 }, {  1.5000, -0.8400, 0.07500 },
+	{  0.8400, -1.5000, 0.07500 }
+};
+
+static void draw_patch(int *index, int flip, float scale);
+static float bernstein(int i, float x);
+
 void glutSolidTeapot(float size)
 {
+	int i;
+
+	size /= 2.0;
+
+	for(i=0; i<NUM_TEAPOT_PATCHES; i++) {
+		float flip = teapot_part_flip[i];
+		float rot = teapot_part_rot[i];
+
+		glMatrixMode(GL_MODELVIEW);
+		glPushMatrix();
+		glTranslatef(0, -3.15 * size * 0.5, 0);
+		glRotatef(rot, 0, 1, 0);
+		glScalef(1, 1, flip);
+		glRotatef(-90, 1, 0, 0);
+
+		draw_patch(teapot_index + i * 16, flip < 0.0 ? 1 : 0, size);
+
+		glPopMatrix();
+	}
 }
 
 void glutWireTeapot(float size)
 {
 }
+
+
+static void bezier_patch(float *res, float *cp, float u, float v)
+{
+	int i, j;
+
+	res[0] = res[1] = res[2] = 0.0f;
+
+	for(j=0; j<4; j++) {
+		for(i=0; i<4; i++) {
+			float bu = bernstein(i, u);
+			float bv = bernstein(j, v);
+
+			res[0] += cp[0] * bu * bv;
+			res[1] += cp[1] * bu * bv;
+			res[2] += cp[2] * bu * bv;
+
+			cp += 3;
+		}
+	}
+}
+
+static float rsqrt(float x)
+{
+	float xhalf = x * 0.5f;
+	int32_t i = *(int32_t*)&x;
+	i = 0x5f3759df - (i >> 1);
+	x = *(float*)&i;
+	x = x * (1.5f - xhalf * x * x);
+	return x;
+}
+
+
+#define CROSS(res, a, b) \
+	do { \
+		(res)[0] = (a)[1] * (b)[2] - (a)[2] * (b)[1]; \
+		(res)[1] = (a)[2] * (b)[0] - (a)[0] * (b)[2]; \
+		(res)[2] = (a)[0] * (b)[1] - (a)[1] * (b)[0]; \
+	} while(0)
+
+#define NORMALIZE(v) \
+	do { \
+		float s = rsqrt((v)[0] * (v)[0] + (v)[1] * (v)[1] + (v)[2] * (v)[2]); \
+		(v)[0] *= s; \
+		(v)[1] *= s; \
+		(v)[2] *= s; \
+	} while(0)
+
+#define DT	0.001
+
+static void bezier_patch_norm(float *res, float *cp, float u, float v)
+{
+	float tang[3], bitan[3], tmp[3];
+
+	bezier_patch(tang, cp, u + DT, v);
+	bezier_patch(tmp, cp, u - DT, v);
+	tang[0] -= tmp[0];
+	tang[1] -= tmp[1];
+	tang[2] -= tmp[2];
+
+	bezier_patch(bitan, cp, u, v + DT);
+	bezier_patch(tmp, cp, u, v - DT);
+	bitan[0] -= tmp[0];
+	bitan[1] -= tmp[1];
+	bitan[2] -= tmp[2];
+
+	CROSS(res, tang, bitan);
+	NORMALIZE(res);
+}
+
+
+
+static float bernstein(int i, float x)
+{
+	float invx = 1.0f - x;
+
+	switch(i) {
+	case 0:
+		return invx * invx * invx;
+	case 1:
+		return 3.0f * x * invx * invx;
+	case 2:
+		return 3.0f * x * x * invx;
+	case 3:
+		return x * x * x;
+	default:
+		break;
+	}
+	return 0.0f;
+}
+
+static void draw_patch(int *index, int flip, float scale)
+{
+	static const float uoffs[2][4] = {{0, 0, 1, 1}, {1, 1, 0, 0}};
+	static const float voffs[4] = {0, 1, 1, 0};
+
+	int i, j, k;
+	float cp[16 * 3];
+	float pt[3], n[3];
+	float u, v;
+	float du = 1.0 / PATCH_SUBDIV;
+	float dv = 1.0 / PATCH_SUBDIV;
+
+	/* collect control points */
+	for(i=0; i<16; i++) {
+		cp[i * 3] = teapot_verts[index[i]][0];
+		cp[i * 3 + 1] = teapot_verts[index[i]][1];
+		cp[i * 3 + 2] = teapot_verts[index[i]][2];
+	}
+
+	glBegin(GL_QUADS);
+	glColor3f(1, 1, 1);
+
+	u = 0;
+	for(i=0; i<PATCH_SUBDIV; i++) {
+		v = 0;
+		for(j=0; j<PATCH_SUBDIV; j++) {
+
+			for(k=0; k<4; k++) {
+				bezier_patch(pt, cp, u + uoffs[flip][k] * du, v + voffs[k] * dv);
+
+				/* top/bottom normal hack */
+				if(pt[2] > 3.14) {
+					n[0] = n[1] = 0.0f;
+					n[2] = 1.0f;
+				} else if(pt[2] < 0.00001) {
+					n[0] = n[1] = 0.0f;
+					n[2] = -1.0f;
+				} else {
+					bezier_patch_norm(n, cp, u + uoffs[flip][k] * du, v + voffs[k] * dv);
+				}
+
+				glTexCoord2f(u, v);
+				glNormal3fv(n);
+				glVertex3f(pt[0] * scale, pt[1] * scale, pt[2] * scale);
+			}
+
+			v += dv;
+		}
+		u += du;
+	}
+
+	glEnd();
+}
diff --git a/test.c b/test.c
index 762fea6..bac41ea 100644
--- a/test.c
+++ b/test.c
@@ -124,6 +124,13 @@ void display(void)
 	glutSolidCone(1.1, 2, 16, 2);
 	glPopMatrix();
 
+	glPushMatrix();
+	glTranslatef(0, -0.5, 2.5);
+	glFrontFace(GL_CW);
+	glutSolidTeapot(1.0);
+	glFrontFace(GL_CCW);
+	glPopMatrix();
+
 	glBegin(GL_QUADS);
 	glNormal3f(0, 1, 0);
 	glVertex3f(-5, -1.3, 5);