From 996597684b69ebcc9e3d9b6b7f9f0b6249c46257 Mon Sep 17 00:00:00 2001 From: Abdelrahman Date: Sat, 24 Aug 2024 00:25:18 +0100 Subject: [PATCH] Add transpose and inverse matrix utilities --- src/vec/vec.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++ src/vec/vec.h | 39 +++++++++++++++++++++++++++ 2 files changed, 114 insertions(+) diff --git a/src/vec/vec.c b/src/vec/vec.c index de689bc..5fcaab3 100644 --- a/src/vec/vec.c +++ b/src/vec/vec.c @@ -55,3 +55,78 @@ M4x4f viewport(f32 x, f32 y, u64 w, u64 h) { return output; } + +M4x4f mat4x4_inv(M4x4f matrix) { + f32 mat[4][4] = mat4x4_to_array(matrix); + f32 dest[4][4] = {0}; + + f32 t[6]; + f32 det; + f32 a = mat[0][0], b = mat[0][1], c = mat[0][2], d = mat[0][3], e = mat[1][0], + f = mat[1][1], g = mat[1][2], h = mat[1][3], i = mat[2][0], j = mat[2][1], + k = mat[2][2], l = mat[2][3], m = mat[3][0], n = mat[3][1], o = mat[3][2], + p = mat[3][3]; + + t[0] = k * p - o * l; + t[1] = j * p - n * l; + t[2] = j * o - n * k; + t[3] = i * p - m * l; + t[4] = i * o - m * k; + t[5] = i * n - m * j; + + dest[0][0] = f * t[0] - g * t[1] + h * t[2]; + dest[1][0] = -(e * t[0] - g * t[3] + h * t[4]); + dest[2][0] = e * t[1] - f * t[3] + h * t[5]; + dest[3][0] = -(e * t[2] - f * t[4] + g * t[5]); + + dest[0][1] = -(b * t[0] - c * t[1] + d * t[2]); + dest[1][1] = a * t[0] - c * t[3] + d * t[4]; + dest[2][1] = -(a * t[1] - b * t[3] + d * t[5]); + dest[3][1] = a * t[2] - b * t[4] + c * t[5]; + + t[0] = g * p - o * h; + t[1] = f * p - n * h; + t[2] = f * o - n * g; + t[3] = e * p - m * h; + t[4] = e * o - m * g; + t[5] = e * n - m * f; + + dest[0][2] = b * t[0] - c * t[1] + d * t[2]; + dest[1][2] = -(a * t[0] - c * t[3] + d * t[4]); + dest[2][2] = a * t[1] - b * t[3] + d * t[5]; + dest[3][2] = -(a * t[2] - b * t[4] + c * t[5]); + + t[0] = g * l - k * h; + t[1] = f * l - j * h; + t[2] = f * k - j * g; + t[3] = e * l - i * h; + t[4] = e * k - i * g; + t[5] = e * j - i * f; + + dest[0][3] = -(b * t[0] - c * t[1] + d * t[2]); + dest[1][3] = a * t[0] - c * t[3] + d * t[4]; + dest[2][3] = -(a * t[1] - b * t[3] + d * t[5]); + dest[3][3] = a * t[2] - b * t[4] + c * t[5]; + + det = 1.0f / + (a * dest[0][0] + b * dest[1][0] + c * dest[2][0] + d * dest[3][0]); + + dest[0][0] *= det; + dest[0][1] *= det; + dest[0][2] *= det; + dest[0][3] *= det; + dest[1][0] *= det; + dest[1][1] *= det; + dest[1][2] *= det; + dest[1][3] *= det; + dest[2][0] *= det; + dest[2][1] *= det; + dest[2][2] *= det; + dest[2][3] *= det; + dest[3][0] *= det; + dest[3][1] *= det; + dest[3][2] *= det; + dest[3][3] *= det; + + return array_to_mat4x4(dest); +} diff --git a/src/vec/vec.h b/src/vec/vec.h index f19b146..bc068a7 100644 --- a/src/vec/vec.h +++ b/src/vec/vec.h @@ -85,6 +85,8 @@ MAKE_LIST_TYPE(V2f); ((T){(ELEM_T)X1 - (ELEM_T)X0, (ELEM_T)Y1 - (ELEM_T)Y0, \ (ELEM_T)Z1 - (ELEM_T)Z0}) +#define V3_to_V4(V3) ((V4f){.x = V3.x, .y = V3.y, .z = V3.z, .w = 1.0f}) + #define dot_v2(V1, V2) ((f32)V1.x * (f32)V2.x + (f32)V1.y * (f32)V2.y) #define dot_v3(V1, V2) \ @@ -140,6 +142,42 @@ MAKE_LIST_TYPE(V2f); .row3 = {0.0f, 0.0f, 0.0f, 1.0f}, \ }) +#define mat4x4_to_array(MAT) \ + ((f32[4][4]){ \ + {MAT.row0.x, MAT.row0.y, MAT.row0.z, MAT.row0.w}, \ + {MAT.row1.x, MAT.row1.y, MAT.row1.z, MAT.row1.w}, \ + {MAT.row2.x, MAT.row2.y, MAT.row2.z, MAT.row2.w}, \ + {MAT.row3.x, MAT.row3.y, MAT.row3.z, MAT.row3.w}, \ + }) + +#define array_to_mat4x4(arr) \ + ((M4x4f){ \ + .row0 = {arr[0][0], arr[0][1], arr[0][2], arr[0][3]}, \ + .row1 = {arr[1][0], arr[1][1], arr[1][2], arr[1][3]}, \ + .row2 = {arr[2][0], arr[2][1], arr[2][2], arr[2][3]}, \ + .row3 = {arr[3][0], arr[3][1], arr[3][2], arr[3][3]}, \ + }) + +#define mat4x4_transpose(MAT) \ + ((M4x4f){ \ + .row0 = {.x = MAT.row0.x, \ + .y = MAT.row1.x, \ + .z = MAT.row2.x, \ + .w = MAT.row3.x}, \ + .row1 = {.x = MAT.row0.y, \ + .y = MAT.row1.y, \ + .z = MAT.row2.y, \ + .w = MAT.row3.y}, \ + .row2 = {.x = MAT.row0.z, \ + .y = MAT.row1.z, \ + .z = MAT.row2.z, \ + .w = MAT.row3.z}, \ + .row3 = {.x = MAT.row0.w, \ + .y = MAT.row1.w, \ + .z = MAT.row2.w, \ + .w = MAT.row3.w}, \ + }) + #define mat4x4_mul(MAT1, MAT2) \ ((M4x4f){ \ .row0.x = MAT1.row0.x * MAT2.row0.x + MAT1.row0.y * MAT2.row1.x + \ @@ -193,5 +231,6 @@ MAKE_LIST_TYPE(V2f); M4x4f lookat(V3f eye, V3f target, V3f up); M4x4f projection(f32 coeff); M4x4f viewport(f32 x, f32 y, u64 w, u64 h); +M4x4f mat4x4_inv(M4x4f matrix); #endif // VEC_H