qt5base-lts/examples/widgets/graphicsview/boxes/glbuffers.cpp
Edward Welbourne 8095c33bcd Use qRadiansToDegrees() and qDegreesToRadians() more widely
Especially in examples, where we should show off our convenience
functions, prefer calling these functions over doing arithmetic with
M_PI (or approximations thereto) and 180 (give or take simple
factors).  This incidentally documents what's going on, just by the
name of the function used (and reveals at least one place where
variables were misnamed; the return from atan is in radians, *not*
degrees).

Task-number: QTBUG-58083
Change-Id: I6e5d66721cafab423378f970af525400423e971e
Reviewed-by: Jüri Valdmann <juri.valdmann@qt.io>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
2017-07-05 10:15:34 +00:00

412 lines
15 KiB
C++

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the demonstration applications of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd nor the names of its
** contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "glbuffers.h"
#include <QtGui/qmatrix4x4.h>
#include <QtCore/qmath.h>
void qgluPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar)
{
const GLdouble ymax = zNear * tan(qDegreesToRadians(fovy) / 2.0);
const GLdouble ymin = -ymax;
const GLdouble xmin = ymin * aspect;
const GLdouble xmax = ymax * aspect;
glFrustum(xmin, xmax, ymin, ymax, zNear, zFar);
}
//============================================================================//
// GLTexture //
//============================================================================//
GLTexture::GLTexture() : m_texture(0), m_failed(false)
{
glGenTextures(1, &m_texture);
}
GLTexture::~GLTexture()
{
glDeleteTextures(1, &m_texture);
}
//============================================================================//
// GLTexture2D //
//============================================================================//
GLTexture2D::GLTexture2D(int width, int height)
{
glBindTexture(GL_TEXTURE_2D, m_texture);
glTexImage2D(GL_TEXTURE_2D, 0, 4, width, height, 0,
GL_BGRA, GL_UNSIGNED_BYTE, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
//glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);
glBindTexture(GL_TEXTURE_2D, 0);
}
GLTexture2D::GLTexture2D(const QString& fileName, int width, int height)
{
// TODO: Add error handling.
QImage image(fileName);
if (image.isNull()) {
m_failed = true;
return;
}
image = image.convertToFormat(QImage::Format_ARGB32);
//qDebug() << "Image size:" << image.width() << "x" << image.height();
if (width <= 0)
width = image.width();
if (height <= 0)
height = image.height();
if (width != image.width() || height != image.height())
image = image.scaled(width, height, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
glBindTexture(GL_TEXTURE_2D, m_texture);
// Works on x86, so probably works on all little-endian systems.
// Does it work on big-endian systems?
glTexImage2D(GL_TEXTURE_2D, 0, 4, image.width(), image.height(), 0,
GL_BGRA, GL_UNSIGNED_BYTE, image.bits());
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
//glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);
glBindTexture(GL_TEXTURE_2D, 0);
}
void GLTexture2D::load(int width, int height, QRgb *data)
{
glBindTexture(GL_TEXTURE_2D, m_texture);
glTexImage2D(GL_TEXTURE_2D, 0, 4, width, height, 0,
GL_BGRA, GL_UNSIGNED_BYTE, data);
glBindTexture(GL_TEXTURE_2D, 0);
}
void GLTexture2D::bind()
{
glBindTexture(GL_TEXTURE_2D, m_texture);
glEnable(GL_TEXTURE_2D);
}
void GLTexture2D::unbind()
{
glBindTexture(GL_TEXTURE_2D, 0);
glDisable(GL_TEXTURE_2D);
}
//============================================================================//
// GLTexture3D //
//============================================================================//
GLTexture3D::GLTexture3D(int width, int height, int depth)
{
GLBUFFERS_ASSERT_OPENGL("GLTexture3D::GLTexture3D", glTexImage3D, return)
glBindTexture(GL_TEXTURE_3D, m_texture);
glTexImage3D(GL_TEXTURE_3D, 0, 4, width, height, depth, 0,
GL_BGRA, GL_UNSIGNED_BYTE, 0);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_REPEAT);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
//glTexParameteri(GL_TEXTURE_3D, GL_GENERATE_MIPMAP, GL_TRUE);
glBindTexture(GL_TEXTURE_3D, 0);
}
void GLTexture3D::load(int width, int height, int depth, QRgb *data)
{
GLBUFFERS_ASSERT_OPENGL("GLTexture3D::load", glTexImage3D, return)
glBindTexture(GL_TEXTURE_3D, m_texture);
glTexImage3D(GL_TEXTURE_3D, 0, 4, width, height, depth, 0,
GL_BGRA, GL_UNSIGNED_BYTE, data);
glBindTexture(GL_TEXTURE_3D, 0);
}
void GLTexture3D::bind()
{
glBindTexture(GL_TEXTURE_3D, m_texture);
glEnable(GL_TEXTURE_3D);
}
void GLTexture3D::unbind()
{
glBindTexture(GL_TEXTURE_3D, 0);
glDisable(GL_TEXTURE_3D);
}
//============================================================================//
// GLTextureCube //
//============================================================================//
GLTextureCube::GLTextureCube(int size)
{
glBindTexture(GL_TEXTURE_CUBE_MAP, m_texture);
for (int i = 0; i < 6; ++i)
glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, 4, size, size, 0,
GL_BGRA, GL_UNSIGNED_BYTE, 0);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
//glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_GENERATE_MIPMAP, GL_TRUE);
glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
}
GLTextureCube::GLTextureCube(const QStringList& fileNames, int size)
{
// TODO: Add error handling.
glBindTexture(GL_TEXTURE_CUBE_MAP, m_texture);
int index = 0;
foreach (QString file, fileNames) {
QImage image(file);
if (image.isNull()) {
m_failed = true;
break;
}
image = image.convertToFormat(QImage::Format_ARGB32);
//qDebug() << "Image size:" << image.width() << "x" << image.height();
if (size <= 0)
size = image.width();
if (size != image.width() || size != image.height())
image = image.scaled(size, size, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
// Works on x86, so probably works on all little-endian systems.
// Does it work on big-endian systems?
glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + index, 0, 4, image.width(), image.height(), 0,
GL_BGRA, GL_UNSIGNED_BYTE, image.bits());
if (++index == 6)
break;
}
// Clear remaining faces.
while (index < 6) {
glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + index, 0, 4, size, size, 0,
GL_BGRA, GL_UNSIGNED_BYTE, 0);
++index;
}
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
//glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_GENERATE_MIPMAP, GL_TRUE);
glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
}
void GLTextureCube::load(int size, int face, QRgb *data)
{
glBindTexture(GL_TEXTURE_CUBE_MAP, m_texture);
glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 0, 4, size, size, 0,
GL_BGRA, GL_UNSIGNED_BYTE, data);
glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
}
void GLTextureCube::bind()
{
glBindTexture(GL_TEXTURE_CUBE_MAP, m_texture);
glEnable(GL_TEXTURE_CUBE_MAP);
}
void GLTextureCube::unbind()
{
glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
glDisable(GL_TEXTURE_CUBE_MAP);
}
//============================================================================//
// GLFrameBufferObject //
//============================================================================//
GLFrameBufferObject::GLFrameBufferObject(int width, int height)
: m_fbo(0)
, m_depthBuffer(0)
, m_width(width)
, m_height(height)
, m_failed(false)
{
GLBUFFERS_ASSERT_OPENGL("GLFrameBufferObject::GLFrameBufferObject",
glGenFramebuffersEXT && glGenRenderbuffersEXT && glBindRenderbufferEXT && glRenderbufferStorageEXT, return)
// TODO: share depth buffers of same size
glGenFramebuffersEXT(1, &m_fbo);
//glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_fbo);
glGenRenderbuffersEXT(1, &m_depthBuffer);
glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, m_depthBuffer);
glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, m_width, m_height);
//glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, m_depthBuffer);
//glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
}
GLFrameBufferObject::~GLFrameBufferObject()
{
GLBUFFERS_ASSERT_OPENGL("GLFrameBufferObject::~GLFrameBufferObject",
glDeleteFramebuffersEXT && glDeleteRenderbuffersEXT, return)
glDeleteFramebuffersEXT(1, &m_fbo);
glDeleteRenderbuffersEXT(1, &m_depthBuffer);
}
void GLFrameBufferObject::setAsRenderTarget(bool state)
{
GLBUFFERS_ASSERT_OPENGL("GLFrameBufferObject::setAsRenderTarget", glBindFramebufferEXT, return)
if (state) {
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_fbo);
glPushAttrib(GL_VIEWPORT_BIT);
glViewport(0, 0, m_width, m_height);
} else {
glPopAttrib();
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
}
}
bool GLFrameBufferObject::isComplete()
{
GLBUFFERS_ASSERT_OPENGL("GLFrameBufferObject::isComplete", glCheckFramebufferStatusEXT, return false)
return GL_FRAMEBUFFER_COMPLETE_EXT == glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
}
//============================================================================//
// GLRenderTargetCube //
//============================================================================//
GLRenderTargetCube::GLRenderTargetCube(int size)
: GLTextureCube(size)
, m_fbo(size, size)
{
}
void GLRenderTargetCube::begin(int face)
{
GLBUFFERS_ASSERT_OPENGL("GLRenderTargetCube::begin",
glFramebufferTexture2DEXT && glFramebufferRenderbufferEXT, return)
m_fbo.setAsRenderTarget(true);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, m_texture, 0);
glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, m_fbo.m_depthBuffer);
}
void GLRenderTargetCube::end()
{
m_fbo.setAsRenderTarget(false);
}
void GLRenderTargetCube::getViewMatrix(QMatrix4x4& mat, int face)
{
if (face < 0 || face >= 6) {
qWarning("GLRenderTargetCube::getViewMatrix: 'face' must be in the range [0, 6). (face == %d)", face);
return;
}
static int perm[6][3] = {
{2, 1, 0},
{2, 1, 0},
{0, 2, 1},
{0, 2, 1},
{0, 1, 2},
{0, 1, 2},
};
static float signs[6][3] = {
{-1.0f, -1.0f, -1.0f},
{+1.0f, -1.0f, +1.0f},
{+1.0f, +1.0f, -1.0f},
{+1.0f, -1.0f, +1.0f},
{+1.0f, -1.0f, -1.0f},
{-1.0f, -1.0f, +1.0f},
};
mat.fill(0.0f);
for (int i = 0; i < 3; ++i)
mat(i, perm[face][i]) = signs[face][i];
mat(3, 3) = 1.0f;
}
void GLRenderTargetCube::getProjectionMatrix(QMatrix4x4& mat, float nearZ, float farZ)
{
static const QMatrix4x4 reference(
1.0f, 0.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f, 0.0f,
0.0f, 0.0f, 0.0f, 0.0f,
0.0f, 0.0f, -1.0f, 0.0f);
mat = reference;
mat(2, 2) = (nearZ+farZ)/(nearZ-farZ);
mat(2, 3) = 2.0f*nearZ*farZ/(nearZ-farZ);
}