gg.m4: fixed some bugs, added ortho projection (#9140)

vlib/gg/m4/graphic.v

@@ -24,7 +24,33 @@ pub fn deg(grad f32) f32 {
 	return (180.0 / math.pi) * grad
 }
 
-// Calculate the perspective matrix
+// calculate the Orthographic projection matrix
+pub fn ortho(left f32, right f32, bottom f32, top f32, z_near f32, z_far f32) Mat4 {
+	rml := right - left
+	rpl := right + left
+	tmb := top - bottom
+	tpb := top + bottom
+	fmn := z_far - z_near
+	fpn := z_far + z_near
+	if fmn != 0 {
+		return Mat4{ e: [
+				2 / rml, 0      ,       0, -(rpl / rml),
+				0      , 2 / tmb,       0, -(tpb / tmb),
+				0      ,       0, 2 / fmn, -(fpn / fmn),
+				0      ,       0,       0,            1,
+			]!
+		}
+	} 
+	return Mat4{ e: [
+			2 / rml, 0      ,       0, -(rpl / rml),
+			0      , 2 / tmb,       0, -(tpb / tmb),
+			0      ,       0,       0,            0,
+			0      ,       0,       0,            1,
+		]!
+	}
+}
+
+// Calculate the perspective matrix using (fov:fov, ar:aspect_ratio ,n:near_pane, f:far_plane) as parameters
 pub fn perspective(fov f32, ar f32, n f32, f f32) Mat4 {
 	ctan := f32(1.0 / math.tan(fov * (f32(math.pi) / 360.0))) // for the FOV we use 360 instead 180
 	return Mat4{ e: [
@@ -66,21 +92,6 @@ pub fn look_at(eye Vec4, center Vec4, up Vec4) Mat4 {
 	}
 }
 
-/*
-hmm_mat4 proj = HMM_Perspective(60.0f, w/h, 0.01f, 10.0f);
-	hmm_mat4 view = HMM_LookAt(HMM_Vec3(0.0f, 1.5f, 6.0f), HMM_Vec3(0.0f, 0.0f, 0.0f), HMM_Vec3(0.0f, 1.0f, 0.0f));
-	hmm_mat4 view_proj = HMM_MultiplyMat4(proj, view);
-	//state.rx += 1.0f; state.ry += 2.0f;
-
-
-	hmm_mat4 rxm = HMM_Rotate(rx, HMM_Vec3(1.0f, 0.0f, 0.0f));
-	hmm_mat4 rym = HMM_Rotate(ry, HMM_Vec3(0.0f, 1.0f, 0.0f));
-
-	hmm_mat4 model = HMM_MultiplyMat4(rxm, rym);
-	hmm_mat4 scale_mx = HMM_Scale(HMM_Vec3(scale, scale, scale));
-	model = HMM_MultiplyMat4(model, scale_mx);
-	hmm_mat4 tmp_res = HMM_MultiplyMat4(view_proj, model);
-*/
 
 // Get the complete transformation matrix for GLSL demos
 pub fn calc_tr_matrices(w f32, h f32, rx f32, ry f32, in_scale f32) Mat4 {

vlib/gg/m4/m4_test.v

@@ -185,6 +185,7 @@ fn test_det() {
 fn test_vec4() {
 	// Test Vec4
 	// println("*** Vector4 ****")
+	assert m4.vec3(1,2,3) == m4.Vec4{[f32(1), 2, 3, 1]!}
 	mut v := m4.Vec4{[f32(1), 2, 3, 4]!}
 	assert v * v.inv() == 4
 	assert v.mul_scalar(1.0 / v.mod()).mod() == 1
@@ -195,13 +196,22 @@ fn test_vec4() {
 	v = m4.Vec4{[f32(1), 2, 3, 0]!}
 	assert m4.abs(v.normalize3().mod3() - 1) < m4.precision
 	assert m4.abs(v.normalize3().mod() - 1) < m4.precision
+	// cross product
 	// x y z
 	// 1 2 3 ==> -3 6 -3 0
 	// 4 5 6
 	// println(m4.Vec4{[f32(1),2,3,2]!} % m4.Vec4{[f32(4),5,6,2]!})
 	assert m4.Vec4{[f32(1), 2, 3, 0]!} % m4.Vec4{[f32(4), 5, 6, 0]!} == m4.Vec4{[ f32(-3),	6,	-3,	0, ]!}
 	assert m4.Vec4{[f32(1), 2, 3, 13]!} % m4.Vec4{[f32(4), 5, 6, 11]!} == m4.Vec4{[	f32(-3), 6,	-3,	0, ]!}
-
+	// matrix * vector
+	a := m4.Mat4{ e: [
+		f32(1),2,3,4
+		5,6,7,8
+		9,10,11,12
+		13,14,15,16
+		]!
+	}
+	assert m4.mul_vec(a, m4.Vec4{[f32(1), 2, 3, 4]!}) == m4.Vec4{[ f32(30),	70,	110,150, ]!}
 	// Rotation
 	// println("*** Rotation ****")
 	rotx := m4.rotate(m4.rad(-90), m4.Vec4{	e: [f32(1.0), 0, 0, 0]!	}).clean()
@@ -211,8 +221,15 @@ fn test_vec4() {
 	// println( roty )
 	// println( rotz )
 	// println( m4.mul_vec(rotx, m4.Vec4{e:[f32(0),0,1,0]!}).clean())
-	assert m4.mul_vec(roty, m4.Vec4{ e: [f32(1.0), 0.0, 0, 0]! }).clean() == m4.Vec4{ e: [f32(0), 0.0, 1, 0]! }
+	assert m4.mul_vec(roty, m4.Vec4{ e: [f32(1.0), 0.0, 0, 0]! }).clean() == m4.Vec4{ e: [f32(0), 0.0, -1, 0]! }
-	assert m4.mul_vec(rotz, m4.Vec4{ e: [f32(1.0), 0.0, 0, 0]! }).clean() == m4.Vec4{ e: [f32(0), -1, 0, 0]! }
+	assert m4.mul_vec(rotz, m4.Vec4{ e: [f32(1.0), 0.0, 0, 0]! }).clean() == m4.Vec4{ e: [f32(0), 1, 0, 0]! }
-	assert m4.mul_vec(rotx, m4.Vec4{ e: [f32(0), 0, 1, 0]! }).clean() == m4.Vec4{ e: [f32(0), 1, 0, 0]! }
+	assert m4.mul_vec(rotx, m4.Vec4{ e: [f32(0), 0, 1, 0]! }).clean() == m4.Vec4{ e: [f32(0), -1, 0, 0]! }
 	// println("****************")
 }
+
+fn test_proj() {
+	ort := m4.ortho(0,300,0,200,0,0)
+	assert m4.mul_vec(ort, m4.Vec4{[ f32(150),	100,	0, 1]!}) == m4.Vec4{[ f32(0),	0,	0, 1]!}
+	assert m4.mul_vec(ort, m4.Vec4{[ f32(0),	0,	0, 1]!}) == m4.Vec4{[ f32(-1),	-1,	0, 1]!}
+	assert m4.mul_vec(ort, m4.Vec4{[ f32(300),	200,	0, 1]!}) == m4.Vec4{[ f32(1),	1,	0, 1]!}
+}

vlib/gg/m4/matrix.v

@@ -41,7 +41,7 @@ pub fn (x Mat4) str() string {
 		return '|${x.e[0]:-6.3},${x.e[1]:-6.3},${x.e[2]:-6.3},${x.e[3]:-6.3}|\n' +
 			'|${x.e[4]:-6.3},${x.e[5]:-6.3},${x.e[6]:-6.3},${x.e[7]:-6.3}|\n' +
 			'|${x.e[8]:-6.3},${x.e[9]:-6.3},${x.e[10]:-6.3},${x.e[11]:-6.3}|\n' +
-			'|${x.e[12]:-6.3},${x.e[13]:-6.3},${x.e[14]:-6.3},${x.e[15]:-6.3}|\n'
+			'|${x.e[12]:-6.3},${x.e[13]:-6.3},${x.e[14]:-6.3},${x.e[15]:-6.3}|'
 	}
 }
 
@@ -410,6 +410,7 @@ pub fn mul(a Mat4, b Mat4) Mat4 {
 // Multiply a Matrix by a vector
 pub fn mul_vec(a Mat4, v Vec4) Vec4 {
 	unsafe {
+/*
 		return Vec4{ e: [
 				a.e[0] * v.e[0] + a.e[4] * v.e[1] + a.e[8] * v.e[2] + a.e[12] * v.e[3],
 				a.e[1] * v.e[0] + a.e[5] * v.e[1] + a.e[9] * v.e[2] + a.e[13] * v.e[3],
@@ -417,6 +418,14 @@ pub fn mul_vec(a Mat4, v Vec4) Vec4 {
 				a.e[3] * v.e[0] + a.e[7] * v.e[1] + a.e[11] * v.e[2] + a.e[15] * v.e[3],
 				]!
 		}
+*/
+		return Vec4{ e: [
+				a.e[0] * v.e[0] + a.e[1] * v.e[1] + a.e[2] * v.e[2] + a.e[3] * v.e[3],
+				a.e[4] * v.e[0] + a.e[5] * v.e[1] + a.e[6] * v.e[2] + a.e[7] * v.e[3],
+				a.e[8] * v.e[0] + a.e[9] * v.e[1] + a.e[10] * v.e[2] + a.e[11] * v.e[3],
+				a.e[12] * v.e[0] + a.e[13] * v.e[1] + a.e[14] * v.e[2] + a.e[15] * v.e[3],
+				]!
+		}
 	}
 }
 

vlib/gg/m4/vector.v

@@ -23,7 +23,12 @@ pub mut:
 *
 *********************************************************************/
 pub fn (x Vec4) str() string {
-	return '|${x.e[0]:-6.3},${x.e[1]:-6.3},${x.e[2]:-6.3},${x.e[3]:-6.3}|\n'
+	return '|${x.e[0]:-6.3},${x.e[1]:-6.3},${x.e[2]:-6.3},${x.e[3]:-6.3}|'
+}
+
+// create a Vec4 function passing x,y,z as parameteres. w is set to 1
+pub fn vec3(x f32, y f32, z f32) Vec4 {
+	return m4.Vec4{e:[x, y, z, 1]!}
 }
 
 // Remove all the raw zeros