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106 lines
2.7 KiB
V
106 lines
2.7 KiB
V
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/**********************************************************************
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*
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* Simply vector/matrix graphic utility
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*
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* Copyright (c) 2021 Dario Deledda. All rights reserved.
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* Use of this source code is governed by an MIT license
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* that can be found in the LICENSE file.
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*
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* TODO:
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**********************************************************************/
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module m4
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import math
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// Translate degrees to radians
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[inline]
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pub fn rad(deg f32) f32 {
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return (math.pi / 180.0) * deg
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}
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// Translate radians to degrees
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[inline]
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pub fn deg(grad f32) f32 {
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return (180.0 / math.pi) * grad
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}
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// Calculate the perspective matrix
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[direct_array_access]
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pub fn perspective(fov f32, ar f32, n f32, f f32) Mat4 {
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unsafe {
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ctan := f32(1.0 / math.tan(fov * (f32(math.pi) / 360.0))) // for the FOV we use 360 instead 180
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return Mat4{ e: [
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ctan / ar, 0, 0, 0,
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0, ctan, 0, 0,
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0, 0, (n + f) / (n - f), -1.0,
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0, 0, (2.0 * n * f) / (n - f), 0,
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]!
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}
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}
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}
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// Calculate the look-at matrix
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[direct_array_access]
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pub fn look_at(eye Vec4, center Vec4, up Vec4) Mat4 {
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unsafe {
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f := (center - eye).normalize3()
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s := (f % up).normalize3()
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u := (s % f)
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return Mat4{ e: [
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/* [0][0] */ s.e[0],
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/* [0][1] */ u.e[0],
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/* [0][2] */ - f.e[0],
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/* [0][3] */ 0,
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/* [1][1] */ s.e[1],
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/* [1][1] */ u.e[1],
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/* [1][2] */ - f.e[1],
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/* [1][3] */ 0,
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/* [2][0] */ s.e[2],
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/* [2][1] */ u.e[2],
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/* [2][2] */ - f.e[2],
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/* [2][3] */ 0,
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/* [3][0] */ - (s * eye),
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/* [3][1] */ - (u * eye),
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/* [3][2] */ f * eye,
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/* [3][3] */ 1,
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]!
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}
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}
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}
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/*
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hmm_mat4 proj = HMM_Perspective(60.0f, w/h, 0.01f, 10.0f);
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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));
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hmm_mat4 view_proj = HMM_MultiplyMat4(proj, view);
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//state.rx += 1.0f; state.ry += 2.0f;
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hmm_mat4 rxm = HMM_Rotate(rx, HMM_Vec3(1.0f, 0.0f, 0.0f));
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hmm_mat4 rym = HMM_Rotate(ry, HMM_Vec3(0.0f, 1.0f, 0.0f));
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hmm_mat4 model = HMM_MultiplyMat4(rxm, rym);
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hmm_mat4 scale_mx = HMM_Scale(HMM_Vec3(scale, scale, scale));
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model = HMM_MultiplyMat4(model, scale_mx);
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hmm_mat4 tmp_res = HMM_MultiplyMat4(view_proj, model);
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*/
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// Get the complete transformation matrix for GLSL demos
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pub fn calc_tr_matrices(w f32, h f32, rx f32, ry f32, in_scale f32) Mat4 {
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proj := perspective(60, w / h, 0.01, 10.0)
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view := look_at(Vec4{ e: [f32(0.0), 1.5, 6, 0]! }, Vec4{ e: [f32(0), 0, 0, 0]! }, Vec4{ e: [f32(0), 1.0, 0, 0]! })
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view_proj := view * proj
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rxm := rotate(rad(rx), Vec4{ e: [f32(1), 0, 0, 0]! })
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rym := rotate(rad(ry), Vec4{ e: [f32(0), 1, 0, 0]! })
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model := rym * rxm
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scale_m := scale(Vec4{ e: [in_scale, in_scale, in_scale, 1]! })
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res := (scale_m * model) * view_proj
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return res
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}
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