OpenGLObject.cpp

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#include "OpenGLObject.h"

GLenum arrayGLPrimitive[] = { GL_TRIANGLES, GL_TRIANGLE_STRIP, GL_QUADS, GL_QUAD_STRIP };
GLenum arrayGLType[] = { GL_VERTEX_ARRAY, GL_NORMAL_ARRAY, GL_COLOR_ARRAY, GL_TEXTURE_COORD_ARRAY };
GLenum arrayGLFormat[] = { GL_FLOAT, GL_UNSIGNED_BYTE };

OpenGLObject::OpenGLObject() {
        vertexBufferID = 0;
        indiceBufferID = 0;
}

OpenGLObject::~OpenGLObject() {
}

bool OpenGLObject::createVertexBuffer() {
        if (GL_ARB_vertex_buffer_object_supported) {
                glGenBuffersARB(1, &vertexBufferID);
                glBindBufferARB(GL_ARRAY_BUFFER_ARB, vertexBufferID);
                glBufferDataARB(GL_ARRAY_BUFFER_ARB, nVertices * vertexSize, vertices, GL_STATIC_DRAW_ARB);

                glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);

                if (nIndices > 0) {
                        glGenBuffersARB(1, &indiceBufferID);
                        glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, indiceBufferID);
                        glBufferDataARB(GL_ELEMENT_ARRAY_BUFFER_ARB, nIndices * indiceSize, indices, GL_STATIC_DRAW_ARB);

                        glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
                }

                LOG_SUCCESS(("Vertex buffer uploaded"));
        }
        else
                LOG_ERROR(("Unable to upload vertex buffer"));

        return true;
}

bool OpenGLObject::clearVertexBuffer() {
        if (GL_ARB_vertex_buffer_object_supported) {
                if (vertexBufferID != 0) glDeleteBuffersARB(1, &vertexBufferID);
                if (indiceBufferID != 0) glDeleteBuffersARB(1, &indiceBufferID);

                LOG_SUCCESS(("Vertex buffer cleared"));
        }
        else
                LOG_ERROR(("Unable to clear vertex buffer"));

        return true;
}

void OpenGLObject::draw() {
        unsigned int i;
        unsigned int nFormats = formats.getCount();

        if (GL_ARB_vertex_buffer_object_supported && vertexBufferID != 0) {
                glBindBufferARB(GL_ARRAY_BUFFER_ARB, vertexBufferID);
        }

        // enable and setup formats
        for (i=0; i<nFormats; i++) {
                Format format = formats[i];
                GLenum form = arrayGLFormat[format.attFormat];
                GLenum type = arrayGLType[format.attType];


                char *bsp = (vertexBufferID != 0)? NULL : vertices;

                switch (format.attType) {
                        case ATT_VERTEX:
                                glVertexPointer(format.size, form, vertexSize, bsp + format.offset);
                                break;
                        case ATT_NORMAL:
                                glNormalPointer(form, vertexSize, bsp + format.offset);
                                break;
                        case ATT_COLOR:
                                glColorPointer(format.size, form, vertexSize, bsp + format.offset);
                                break;
                        case ATT_TEX:
                                glTexCoordPointer(format.size, form, vertexSize, bsp + format.offset);
                }
                glEnableClientState(type);
        }

        // fix indices (if any) and draw
        if (nIndices == 0) {
                glDrawArrays(arrayGLPrimitive[primitive], 0, nVertices);
        }
        else {
                if (indiceBufferID != 0) glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, indiceBufferID);

                glDrawElements(arrayGLPrimitive[primitive], nIndices, GL_UNSIGNED_SHORT, (indiceBufferID != 0)? NULL : indices);

                if (indiceBufferID != 0) glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
        }

        // disable formats
        for (i=0; i<nFormats; i++) {
                glDisableClientState(arrayGLType[formats[i].attType]);
        }

        if (GL_ARB_vertex_buffer_object_supported && vertexBufferID != 0) {
                glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
        }
}

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