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50 | |
51 | #include "cuberenderer.h" |
52 | #include <QOpenGLContext> |
53 | #include <QOpenGLFunctions> |
54 | #include <QOpenGLShaderProgram> |
55 | #include <QOpenGLVertexArrayObject> |
56 | #include <QOpenGLBuffer> |
57 | #include <QOpenGLVertexArrayObject> |
58 | #include <QOffscreenSurface> |
59 | #include <QWindow> |
60 | |
61 | CubeRenderer::CubeRenderer(QOffscreenSurface *offscreenSurface) |
62 | : m_offscreenSurface(offscreenSurface), |
63 | m_context(nullptr), |
64 | m_program(nullptr), |
65 | m_vbo(nullptr), |
66 | m_vao(nullptr), |
67 | m_matrixLoc(0) |
68 | { |
69 | } |
70 | |
71 | CubeRenderer::~CubeRenderer() |
72 | { |
73 | // Use a temporary offscreen surface to do the cleanup. |
74 | // There may not be a native window surface available anymore at this stage. |
75 | m_context->makeCurrent(surface: m_offscreenSurface); |
76 | |
77 | delete m_program; |
78 | delete m_vbo; |
79 | delete m_vao; |
80 | |
81 | m_context->doneCurrent(); |
82 | delete m_context; |
83 | } |
84 | |
85 | void CubeRenderer::init(QWindow *w, QOpenGLContext *share) |
86 | { |
87 | m_context = new QOpenGLContext; |
88 | m_context->setShareContext(share); |
89 | m_context->setFormat(w->requestedFormat()); |
90 | m_context->create(); |
91 | if (!m_context->makeCurrent(surface: w)) |
92 | return; |
93 | |
94 | QOpenGLFunctions *f = m_context->functions(); |
95 | f->glClearColor(red: 0.0f, green: 0.1f, blue: 0.25f, alpha: 1.0f); |
96 | f->glViewport(x: 0, y: 0, width: w->width() * w->devicePixelRatio(), height: w->height() * w->devicePixelRatio()); |
97 | |
98 | static const char *vertexShaderSource = |
99 | "attribute highp vec4 vertex;\n" |
100 | "attribute lowp vec2 coord;\n" |
101 | "varying lowp vec2 v_coord;\n" |
102 | "uniform highp mat4 matrix;\n" |
103 | "void main() {\n" |
104 | " v_coord = coord;\n" |
105 | " gl_Position = matrix * vertex;\n" |
106 | "}\n" ; |
107 | static const char *fragmentShaderSource = |
108 | "varying lowp vec2 v_coord;\n" |
109 | "uniform sampler2D sampler;\n" |
110 | "void main() {\n" |
111 | " gl_FragColor = vec4(texture2D(sampler, v_coord).rgb, 1.0);\n" |
112 | "}\n" ; |
113 | m_program = new QOpenGLShaderProgram; |
114 | m_program->addCacheableShaderFromSourceCode(type: QOpenGLShader::Vertex, source: vertexShaderSource); |
115 | m_program->addCacheableShaderFromSourceCode(type: QOpenGLShader::Fragment, source: fragmentShaderSource); |
116 | m_program->bindAttributeLocation(name: "vertex" , location: 0); |
117 | m_program->bindAttributeLocation(name: "coord" , location: 1); |
118 | m_program->link(); |
119 | m_matrixLoc = m_program->uniformLocation(name: "matrix" ); |
120 | |
121 | m_vao = new QOpenGLVertexArrayObject; |
122 | m_vao->create(); |
123 | QOpenGLVertexArrayObject::Binder vaoBinder(m_vao); |
124 | |
125 | m_vbo = new QOpenGLBuffer; |
126 | m_vbo->create(); |
127 | m_vbo->bind(); |
128 | |
129 | GLfloat v[] = { |
130 | -0.5, 0.5, 0.5, 0.5,-0.5,0.5,-0.5,-0.5,0.5, |
131 | 0.5, -0.5, 0.5, -0.5,0.5,0.5,0.5,0.5,0.5, |
132 | -0.5, -0.5, -0.5, 0.5,-0.5,-0.5,-0.5,0.5,-0.5, |
133 | 0.5, 0.5, -0.5, -0.5,0.5,-0.5,0.5,-0.5,-0.5, |
134 | |
135 | 0.5, -0.5, -0.5, 0.5,-0.5,0.5,0.5,0.5,-0.5, |
136 | 0.5, 0.5, 0.5, 0.5,0.5,-0.5,0.5,-0.5,0.5, |
137 | -0.5, 0.5, -0.5, -0.5,-0.5,0.5,-0.5,-0.5,-0.5, |
138 | -0.5, -0.5, 0.5, -0.5,0.5,-0.5,-0.5,0.5,0.5, |
139 | |
140 | 0.5, 0.5, -0.5, -0.5, 0.5, 0.5, -0.5, 0.5, -0.5, |
141 | -0.5, 0.5, 0.5, 0.5, 0.5, -0.5, 0.5, 0.5, 0.5, |
142 | -0.5, -0.5, -0.5, -0.5, -0.5, 0.5, 0.5, -0.5, -0.5, |
143 | 0.5, -0.5, 0.5, 0.5, -0.5, -0.5, -0.5, -0.5, 0.5 |
144 | }; |
145 | GLfloat texCoords[] = { |
146 | 0.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f, |
147 | 1.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f, |
148 | 1.0f,1.0f, 1.0f,0.0f, 0.0f,1.0f, |
149 | 0.0f,0.0f, 0.0f,1.0f, 1.0f,0.0f, |
150 | |
151 | 1.0f,1.0f, 1.0f,0.0f, 0.0f,1.0f, |
152 | 0.0f,0.0f, 0.0f,1.0f, 1.0f,0.0f, |
153 | 0.0f,0.0f, 1.0f,1.0f, 1.0f,0.0f, |
154 | 1.0f,1.0f, 0.0f,0.0f, 0.0f,1.0f, |
155 | |
156 | 0.0f,1.0f, 1.0f,0.0f, 1.0f,1.0f, |
157 | 1.0f,0.0f, 0.0f,1.0f, 0.0f,0.0f, |
158 | 1.0f,0.0f, 1.0f,1.0f, 0.0f,0.0f, |
159 | 0.0f,1.0f, 0.0f,0.0f, 1.0f,1.0f |
160 | }; |
161 | |
162 | const int vertexCount = 36; |
163 | m_vbo->allocate(count: sizeof(GLfloat) * vertexCount * 5); |
164 | m_vbo->write(offset: 0, data: v, count: sizeof(GLfloat) * vertexCount * 3); |
165 | m_vbo->write(offset: sizeof(GLfloat) * vertexCount * 3, data: texCoords, count: sizeof(GLfloat) * vertexCount * 2); |
166 | m_vbo->release(); |
167 | |
168 | if (m_vao->isCreated()) |
169 | setupVertexAttribs(); |
170 | } |
171 | |
172 | void CubeRenderer::resize(int w, int h) |
173 | { |
174 | m_proj.setToIdentity(); |
175 | m_proj.perspective(verticalAngle: 45, aspectRatio: w / float(h), nearPlane: 0.01f, farPlane: 100.0f); |
176 | } |
177 | |
178 | void CubeRenderer::setupVertexAttribs() |
179 | { |
180 | m_vbo->bind(); |
181 | m_program->enableAttributeArray(location: 0); |
182 | m_program->enableAttributeArray(location: 1); |
183 | m_context->functions()->glVertexAttribPointer(indx: 0, size: 3, GL_FLOAT, GL_FALSE, stride: 0, ptr: nullptr); |
184 | m_context->functions()->glVertexAttribPointer(indx: 1, size: 2, GL_FLOAT, GL_FALSE, stride: 0, |
185 | ptr: (const void *)(36 * 3 * sizeof(GLfloat))); |
186 | m_vbo->release(); |
187 | } |
188 | |
189 | void CubeRenderer::render(QWindow *w, QOpenGLContext *share, uint texture) |
190 | { |
191 | if (!m_context) |
192 | init(w, share); |
193 | |
194 | if (!m_context->makeCurrent(surface: w)) |
195 | return; |
196 | |
197 | QOpenGLFunctions *f = m_context->functions(); |
198 | f->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); |
199 | |
200 | if (texture) { |
201 | f->glBindTexture(GL_TEXTURE_2D, texture); |
202 | f->glFrontFace(GL_CW); // because our cube's vertex data is such |
203 | f->glEnable(GL_CULL_FACE); |
204 | f->glEnable(GL_DEPTH_TEST); |
205 | |
206 | m_program->bind(); |
207 | QOpenGLVertexArrayObject::Binder vaoBinder(m_vao); |
208 | // If VAOs are not supported, set the vertex attributes every time. |
209 | if (!m_vao->isCreated()) |
210 | setupVertexAttribs(); |
211 | |
212 | static GLfloat angle = 0; |
213 | QMatrix4x4 m; |
214 | m.translate(x: 0, y: 0, z: -2); |
215 | m.rotate(angle: 90, x: 0, y: 0, z: 1); |
216 | m.rotate(angle, x: 0.5, y: 1, z: 0); |
217 | angle += 0.5f; |
218 | |
219 | m_program->setUniformValue(location: m_matrixLoc, value: m_proj * m); |
220 | |
221 | // Draw the cube. |
222 | f->glDrawArrays(GL_TRIANGLES, first: 0, count: 36); |
223 | } |
224 | |
225 | m_context->swapBuffers(surface: w); |
226 | } |
227 | |