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
|
/*
* nextpnr -- Next Generation Place and Route
*
* Copyright (C) 2018 Serge Bazanski <q3k@q3k.org>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#ifndef LINESHADER_H
#define LINESHADER_H
#include <QOpenGLBuffer>
#include <QOpenGLFunctions>
#include <QOpenGLShaderProgram>
#include <QOpenGLVertexArrayObject>
#include <QOpenGLWidget>
#include <array>
#include "log.h"
#include "nextpnr.h"
NEXTPNR_NAMESPACE_BEGIN
// Vertex2DPOD is a structure of X, Y coordinates that can be passed to OpenGL
// directly.
NPNR_PACKED_STRUCT(struct Vertex2DPOD {
GLfloat x;
GLfloat y;
Vertex2DPOD(GLfloat X, GLfloat Y) : x(X), y(Y) {}
});
// LineShaderData is a built set of vertices that can be rendered by the
// LineShader.
// Each LineShaderData can have its' own color and thickness.
struct LineShaderData
{
std::vector<Vertex2DPOD> vertices;
std::vector<Vertex2DPOD> normals;
std::vector<GLfloat> miters;
std::vector<GLuint> indices;
int last_render = 0;
void clear(void)
{
vertices.clear();
normals.clear();
miters.clear();
indices.clear();
}
};
// PolyLine is a set of segments defined by points, that can be built to a
// ShaderLine for GPU rendering.
class PolyLine
{
private:
std::vector<QVector2D> points_;
bool closed_;
void buildPoint(LineShaderData *building, const QVector2D *prev, const QVector2D *cur, const QVector2D *next) const;
public:
// Create an empty PolyLine.
PolyLine(bool closed = false) : closed_(closed) {}
// Create a non-closed polyline consisting of one segment.
PolyLine(float x0, float y0, float x1, float y1) : closed_(false)
{
point(x0, y0);
point(x1, y1);
}
// Add a point to the PolyLine.
void point(float x, float y) { points_.push_back(QVector2D(x, y)); }
// Built PolyLine to shader data.
void build(LineShaderData &target) const;
// Set whether line is closed (ie. a loop).
void setClosed(bool closed) { closed_ = closed; }
};
// LineShader is an OpenGL shader program that renders LineShaderData on the
// GPU.
// The LineShader expects two vertices per line point. It will push those
// vertices along the given normal * miter. This is used to 'stretch' the line
// to be as wide as the given thickness. The normal and miter are calculated
// by the PolyLine build method in order to construct a constant thickness line
// with miter edge joints.
//
// +------+------+
//
// |
// PolyLine.build()
// |
// V
//
// ^ ^ ^
// | | | <--- normal vectors (x2, pointing in the same
// +/+----+/+----+/+ direction)
//
// |
// vertex shader
// |
// V
//
// +------+------+ ^ by normal * miter * thickness/2
// | | |
// +------+------+ V by normal * miter * thickness/2
//
// (miter is flipped for every second vertex generated)
class LineShader
{
private:
QObject *parent_;
QOpenGLShaderProgram *program_;
// GL attribute locations.
struct
{
// original position of line vertex
GLuint position;
// normal by which vertex should be translated
GLuint normal;
// scalar defining:
// - how stretched the normal vector should be to
// compensate for bends
// - which way the normal should be applied (+1 for one vertex, -1
// for the other)
GLuint miter;
} attributes_;
// GL buffers
struct Buffers
{
QOpenGLBuffer position;
QOpenGLBuffer normal;
QOpenGLBuffer miter;
QOpenGLBuffer index;
QOpenGLVertexArrayObject vao;
int indices = 0;
int last_vbo_update = 0;
};
std::array<Buffers, GraphicElement::STYLE_MAX> buffers_;
// GL uniform locations.
struct
{
// combines m/v/p matrix to apply
GLuint projection;
// desired thickness of line
GLuint thickness;
// color of line
GLuint color;
} uniforms_;
public:
LineShader(QObject *parent) : parent_(parent), program_(nullptr) {}
static constexpr const char *vertexShaderSource_ =
"#version 150\n"
"in highp vec2 position;\n"
"in highp vec2 normal;\n"
"in highp float miter;\n"
"uniform highp float thickness;\n"
"uniform highp mat4 projection;\n"
"void main() {\n"
" vec2 p = position.xy + vec2(normal * thickness/2.0 / miter);\n"
" gl_Position = projection * vec4(p, 0.0, 1.0);\n"
"}\n";
static constexpr const char *fragmentShaderSource_ = "#version 150\n"
"uniform lowp vec4 color;\n"
"out vec4 Out_Color;\n"
"void main() {\n"
" Out_Color = color;\n"
"}\n";
// Must be called on initialization.
bool compile(void);
void update_vbos(enum GraphicElement::style_t style, const LineShaderData &line);
// Render a LineShaderData with a given M/V/P transformation.
void draw(enum GraphicElement::style_t style, const QColor &color, float thickness, const QMatrix4x4 &projection);
};
NEXTPNR_NAMESPACE_END
#endif
|
