worked on OpenGL ES

map/Geometry.cpp

@@ -0,0 +1,124 @@
+#include "Geometry.h"
+
+#include <QVector2D>
+#include <QVector3D>
+
+struct VertexData
+{
+	QVector3D position;
+	QVector2D texCoord;
+};
+
+Geometry::Geometry() : indexBuf(QOpenGLBuffer::IndexBuffer) {
+
+	initializeOpenGLFunctions();
+
+	// Generate 2 VBOs
+	arrayBuf.create();
+	indexBuf.create();
+
+	// Initializes cube geometry and transfers it to VBOs
+	initCubeGeometry();
+
+}
+
+Geometry::~Geometry() {
+	arrayBuf.destroy();
+	indexBuf.destroy();
+}
+
+void Geometry::initCubeGeometry() {
+
+	// For cube we would need only 8 vertices but we have to
+	// duplicate vertex for each face because texture coordinate
+	// is different.
+	VertexData vertices[] = {
+		// Vertex data for face 0
+		{QVector3D(-1.0f, -1.0f,  1.0f), QVector2D(0.0f, 0.0f)},  // v0
+		{QVector3D( 1.0f, -1.0f,  1.0f), QVector2D(0.33f, 0.0f)}, // v1
+		{QVector3D(-1.0f,  1.0f,  1.0f), QVector2D(0.0f, 0.5f)},  // v2
+		{QVector3D( 1.0f,  1.0f,  1.0f), QVector2D(0.33f, 0.5f)}, // v3
+
+		// Vertex data for face 1
+		{QVector3D( 1.0f, -1.0f,  1.0f), QVector2D( 0.0f, 0.5f)}, // v4
+		{QVector3D( 1.0f, -1.0f, -1.0f), QVector2D(0.33f, 0.5f)}, // v5
+		{QVector3D( 1.0f,  1.0f,  1.0f), QVector2D(0.0f, 1.0f)},  // v6
+		{QVector3D( 1.0f,  1.0f, -1.0f), QVector2D(0.33f, 1.0f)}, // v7
+
+		// Vertex data for face 2
+		{QVector3D( 1.0f, -1.0f, -1.0f), QVector2D(0.66f, 0.5f)}, // v8
+		{QVector3D(-1.0f, -1.0f, -1.0f), QVector2D(1.0f, 0.5f)},  // v9
+		{QVector3D( 1.0f,  1.0f, -1.0f), QVector2D(0.66f, 1.0f)}, // v10
+		{QVector3D(-1.0f,  1.0f, -1.0f), QVector2D(1.0f, 1.0f)},  // v11
+
+		// Vertex data for face 3
+		{QVector3D(-1.0f, -1.0f, -1.0f), QVector2D(0.66f, 0.0f)}, // v12
+		{QVector3D(-1.0f, -1.0f,  1.0f), QVector2D(1.0f, 0.0f)},  // v13
+		{QVector3D(-1.0f,  1.0f, -1.0f), QVector2D(0.66f, 0.5f)}, // v14
+		{QVector3D(-1.0f,  1.0f,  1.0f), QVector2D(1.0f, 0.5f)},  // v15
+
+		// Vertex data for face 4
+		{QVector3D(-1.0f, -1.0f, -1.0f), QVector2D(0.33f, 0.0f)}, // v16
+		{QVector3D( 1.0f, -1.0f, -1.0f), QVector2D(0.66f, 0.0f)}, // v17
+		{QVector3D(-1.0f, -1.0f,  1.0f), QVector2D(0.33f, 0.5f)}, // v18
+		{QVector3D( 1.0f, -1.0f,  1.0f), QVector2D(0.66f, 0.5f)}, // v19
+
+		// Vertex data for face 5
+		{QVector3D(-1.0f,  1.0f,  1.0f), QVector2D(0.33f, 0.5f)}, // v20
+		{QVector3D( 1.0f,  1.0f,  1.0f), QVector2D(0.66f, 0.5f)}, // v21
+		{QVector3D(-1.0f,  1.0f, -1.0f), QVector2D(0.33f, 1.0f)}, // v22
+		{QVector3D( 1.0f,  1.0f, -1.0f), QVector2D(0.66f, 1.0f)}  // v23
+	};
+
+	// Indices for drawing cube faces using triangle strips.
+	// Triangle strips can be connected by duplicating indices
+	// between the strips. If connecting strips have opposite
+	// vertex order then last index of the first strip and first
+	// index of the second strip needs to be duplicated. If
+	// connecting strips have same vertex order then only last
+	// index of the first strip needs to be duplicated.
+	GLushort indices[] = {
+		 0,  1,  2,  3,  3,     // Face 0 - triangle strip ( v0,  v1,  v2,  v3)
+		 4,  4,  5,  6,  7,  7, // Face 1 - triangle strip ( v4,  v5,  v6,  v7)
+		 8,  8,  9, 10, 11, 11, // Face 2 - triangle strip ( v8,  v9, v10, v11)
+		12, 12, 13, 14, 15, 15, // Face 3 - triangle strip (v12, v13, v14, v15)
+		16, 16, 17, 18, 19, 19, // Face 4 - triangle strip (v16, v17, v18, v19)
+		20, 20, 21, 22, 23      // Face 5 - triangle strip (v20, v21, v22, v23)
+	};
+
+	// Transfer vertex data to VBO 0
+	arrayBuf.bind();
+	arrayBuf.allocate(vertices, 24 * sizeof(VertexData));
+
+	// Transfer index data to VBO 1
+	indexBuf.bind();
+	indexBuf.allocate(indices, 34 * sizeof(GLushort));
+
+}
+
+void Geometry::drawCubeGeometry(QOpenGLShaderProgram *program) {
+
+	// Tell OpenGL which VBOs to use
+	arrayBuf.bind();
+	indexBuf.bind();
+
+	// Offset for position
+	quintptr offset = 0;
+
+	// Tell OpenGL programmable pipeline how to locate vertex position data
+	int vertexLocation = program->attributeLocation("a_position");
+	program->enableAttributeArray(vertexLocation);
+	program->setAttributeBuffer(vertexLocation, GL_FLOAT, offset, 3, sizeof(VertexData));
+
+	// Offset for texture coordinate
+	offset += sizeof(QVector3D);
+
+	// Tell OpenGL programmable pipeline how to locate vertex texture coordinate data
+	int texcoordLocation = program->attributeLocation("a_texcoord");
+	program->enableAttributeArray(texcoordLocation);
+	program->setAttributeBuffer(texcoordLocation, GL_FLOAT, offset, 2, sizeof(VertexData));
+
+	// Draw cube geometry using indices from VBO 1
+	glDrawElements(GL_TRIANGLE_STRIP, 34, GL_UNSIGNED_SHORT, 0);
+
+}