1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
|
#include "math.h"
#include "options33.h"
#include "types33.h"
#include "display33.h"
#include "scene33.h"
#include "strings33.h"
#include "logger33.h"
#define _FOV_HALF (0.78539816339744830962/2.0)
#define _NEAR 1.0
#define _FAR 24.0
static Mat4 _projectionMatrix = {0,};
static Mat4 _viewMatrix;
static Mat4 _worldMatrix;
static f64 _preXformedModelVertices[ E33_VERTICES_PER_MODEL_MAX ][4];
static void _draw_line( Vec2 v0, Vec2 v1, u32 colour );
Error graphics33_init( void )
{
f64 ar, cot;
f64 displayW = (f64)__display.surface.w;
f64 displayH = (f64)__display.surface.h;
ar = displayW / displayH;
cot = 1.0 / tan( _FOV_HALF );
_projectionMatrix[ 0] = cot / ar;
_projectionMatrix[ 5] = cot;
_projectionMatrix[10] = _FAR / (_FAR - _NEAR);
_projectionMatrix[11] = 1.0;
_projectionMatrix[14] = -_NEAR * (_FAR / (_FAR - _NEAR));
return E33_EXIT_SUCCESS;
}
Error graphics33_term( void )
{
return E33_EXIT_SUCCESS;
}
void graphics33_update( void )
{
math33_create_view_matrix(__scene.camera.t, __scene.camera.r, _viewMatrix );
VxP( _viewMatrix, _projectionMatrix );
}
void graphics33_decompose_scene( void )
{
extern Scene33 __scene;
Size i, j;
Size displayW = __display.surface.w;
Size displayH = __display.surface.h;
Model33 *model = &__scene.cube;
ModelEdge33 *medges = model->medges;
Size *sedges = model->sedges;
Size modelVertexCount = model->vertexCount;
Size modelSurfaceCount = model->surfaceCount;
math33_create_world_matrix( model->t, model->r, model->s, _worldMatrix );
MxM4( _worldMatrix, _viewMatrix );
#define pV _preXformedModelVertices
for( i = 0; i < modelVertexCount; ++i ) {
f64 iw;
V4xMt( pV[i], model->vertices[i], _worldMatrix );
iw = 1.0 / pV[i][3];
pV[i][0] = ( ((pV[i][0] * iw) + 1.0) * 0.5 );
pV[i][1] = ( ((pV[i][1] * iw) + 1.0) * 0.5 );
}
for( i = 0; i < modelSurfaceCount; ++i )
{
Vec4 v[16];
Size a[2], b[2], c[2];
Boolean needsClippage = 0;
a[0] = medges[ sedges[i*3 ] ].vertices[0];
a[1] = medges[ sedges[i*3 ] ].vertices[1];
b[0] = medges[ sedges[i*3+1] ].vertices[0];
b[1] = medges[ sedges[i*3+1] ].vertices[1];
c[0] = medges[ sedges[i*3+2] ].vertices[0];
c[1] = medges[ sedges[i*3+2] ].vertices[1];
if( a[0] == b[0] )
{
Size tmp = a[0];
a[0] = a[1];
a[1] = tmp;
}
else if( a[1] == b[1] )
{
Size tmp = b[0];
b[0] = b[1];
b[1] = tmp;
}
if( c[1] != a[0] ) {
Size tmp = c[0];
c[0] = c[1];
c[1] = tmp;
}
if( ( (pV[a[0]][0] - pV[b[0]][0]) * (pV[c[0]][1] - pV[b[0]][1]) -
(pV[a[0]][1] - pV[b[0]][1]) * (pV[c[0]][0] - pV[b[0]][0]) ) <= 0 ) {
continue;
}
v[0][3] = pV[a[0]][3];
if( v[0][3] <= _NEAR ) continue;
if( v[0][3] > _FAR ) continue;
v[0][0] = pV[a[0]][0];
v[0][1] = pV[a[0]][1];
v[0][2] = pV[a[0]][2];
v[1][3] = pV[b[0]][3];
if( v[1][3] <= _NEAR ) continue;
if( v[1][3] > _FAR ) continue;
v[1][0] = pV[b[0]][0];
v[1][1] = pV[b[0]][1];
v[1][2] = pV[b[0]][2];
v[2][3] = pV[c[0]][3];
if( v[2][3] <= _NEAR ) continue;
if( v[2][3] > _FAR ) continue;
v[2][0] = pV[c[0]][0];
v[2][1] = pV[c[0]][1];
v[2][2] = pV[c[0]][2];
v[0][0] *= (f64)(displayW - 1);
v[0][1] *= (f64)(displayH - 1);
v[1][0] *= (f64)(displayW - 1);
v[1][1] *= (f64)(displayH - 1);
v[2][0] *= (f64)(displayW - 1);
v[2][1] *= (f64)(displayH - 1);
_draw_line( v[0], v[1], CYAN );
_draw_line( v[1], v[2], CYAN );
_draw_line( v[2], v[0], CYAN );
}
#undef pV
}
static void _draw_line( Vec2 v0, Vec2 v1, u32 colour )
{
u32 *dest = __display.surface.data;
Size w = __display.surface.w;
Size h = __display.surface.h;
Size x0 = (Size)(v0[0] + 0.5 );
Size y0 = (Size)(v0[1] + 0.5 );
Size x1 = (Size)(v1[0] + 0.5 );
Size y1 = (Size)(v1[1] + 0.5 );
Size sx, sy;
Size dx, dy, error;
dx = (x1 - x0);
if( dx < 0 ) { dx = -dx; }
sx = -1; if( x0 < x1 ) sx = 1;
dy = -(y1 - y0);
if( dy > 0 ) { dy = -dy; }
sy = -1; if( y0 < y1 ) sy = 1;
error = dx + dy;
while( 1 )
{
Size e2;
dest[ x0 + y0 * w ] = colour;
if( (x0 == x1) && (y0 == y1) ) {
break;
}
e2 = error << 1;
if( e2 >= dy )
{
if( x0 == x1 ) {
break;
}
error += dy;
x0 += sx;
}
if( e2 <= dx )
{
if( y0 == y1 ) {
break;
}
error += dx;
y0 += sy;
}
}
}
|
