【发布时间】：2014-07-21 18:56:22
【问题描述】：
我编写了代码来重塑已纹理化的四边形。当我拉伸四边形时，图像确实会按照我的预期拉伸。当我拉伸图像时，我似乎有两个不同的三角形被拉伸，而不是一个单一的四边形。左上角的像素拉伸在一起，但它们不会影响右下角的像素。反之亦然。有没有我应该设置的设置来延伸整个四边形。
这是一张图片：
要使用我的代码，您可以使用箭头键来移动角落。按空格键切换控制哪个角。
我的代码
// textureMapping.cpp
#include <OpenGL/gl.h>
#include <OpenGL/glu.h>
#include <GLUT/glut.h>
#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
static GLuint texName;
int mode = 0;
double tol = 0.2f;
double xLoc = 0.0;
double yLoc = 0.0;
double xLocLL = 0.0;
double yLocLL = 0.0;
double xLocUL = 0.0;
double yLocUL = 0.0;
double xLocLR = 0.0;
double yLocLR = 0.0;
double xLocUR = 0.0;
double yLocUR = 0.0;
void init(void)
{
cv::Mat image = cv::imread("lena.tiff");
//cv::Mat flipped;
//cv::flip(image, flipped, 0);
//image = flipped;
if(image.empty()){
std::cout << "image empty" << std::endl;
}else{
cv::flip(image, image, 0);
glGenTextures(1, &texName);
glBindTexture(GL_TEXTURE_2D, texName);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// Set texture clamping method
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexImage2D(GL_TEXTURE_2D, // Type of texture
0, // Pyramid level (for mip-mapping) - 0 is the top level
GL_RGB, // Internal colour format to convert to
image.cols, // Image width i.e. 640 for Kinect in standard mode
image.rows, // Image height i.e. 480 for Kinect in standard mode
0, // Border width in pixels (can either be 1 or 0)
GL_BGR, // Input image format (i.e. GL_RGB, GL_RGBA, GL_BGR etc.)
GL_UNSIGNED_BYTE, // Image data type
image.ptr()); // The actual image data itself
glGenerateMipmap(GL_TEXTURE_2D);
}
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glEnable(GL_TEXTURE_2D);
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
glBindTexture(GL_TEXTURE_2D, texName);
glBegin(GL_QUADS);
glTexCoord2f(0.0, 0.0); glVertex3f(-1.0+xLoc+xLocLL, -1.0+yLoc+yLocLL, 0.0);
glTexCoord2f(0.0, 1.0); glVertex3f(-1.0+xLoc+xLocUL, 1.0+yLoc+yLocUL, 0.0);
glTexCoord2f(1.0, 1.0); glVertex3f(1.0+xLoc+xLocUR, 1.0+yLoc+yLocUR, 0.0);
glTexCoord2f(1.0, 0.0); glVertex3f(1.0+xLoc+xLocLR, -1.0+yLoc+yLocLR, 0.0);
//glTexCoord2f(0.0, 0.0); glVertex3f(-1.0+xLoc, -1.0+yLoc, 0.0);
//glTexCoord2f(0.0, 1.0); glVertex3f(-1.0+xLoc, 1.0+yLoc, 0.0);
//glTexCoord2f(1.0, 1.0); glVertex3f(1.0+xLoc, 1.0+yLoc, 0.0);
//glTexCoord2f(1.0, 0.0); glVertex3f(1.0+xLoc, -1.0+yLoc, 0.0);
glEnd();
glFlush();
glDisable(GL_TEXTURE_2D);
glutSwapBuffers();
}
void reshape(int w, int h)
{
glViewport(0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60.0, (GLfloat) w/(GLfloat) h, 1.0, 30.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0.0, -3.6);
}
void keyboard (unsigned char key, int x, int y)
{
switch (key) {
case 27:
exit(0);
break;
case 32:
mode += 1;
if (mode == 5)
{
mode = 0;
}
break;
default:
break;
}
}
void processSpecialKeys(int key, int x, int y) {
switch(key) {
case GLUT_KEY_LEFT:
switch(mode)
{
case 0:
xLoc -= tol;
break;
case 1:
xLocLL -= tol;
break;
case 2:
xLocUL -= tol;
break;
case 3:
xLocUR -= tol;
break;
case 4:
xLocLR -= tol;
break;
}
break;
case GLUT_KEY_RIGHT:
switch(mode)
{
case 0:
xLoc += tol;
break;
case 1:
xLocLL += tol;
break;
case 2:
xLocUL += tol;
break;
case 3:
xLocUR += tol;
break;
case 4:
xLocLR += tol;
break;
}
break;
case GLUT_KEY_DOWN:
switch(mode)
{
case 0:
yLoc -= tol;
break;
case 1:
yLocLL -= tol;
break;
case 2:
yLocUL -= tol;
break;
case 3:
yLocUR -= tol;
break;
case 4:
yLocLR -= tol;
break;
}
break;
case GLUT_KEY_UP:
switch(mode)
{
case 0:
yLoc += tol;
break;
case 1:
yLocLL += tol;
break;
case 2:
yLocUL += tol;
break;
case 3:
yLocUR += tol;
break;
case 4:
yLocLR += tol;
break;
}
break;
}
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(500, 500);
glutInitWindowPosition(100, 100);
glutCreateWindow(argv[0]);
init();
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutIdleFunc(display);
glutKeyboardFunc(keyboard);
glutSpecialFunc(processSpecialKeys);
glutMainLoop();
return 0;
}
生成文件
textureMapping: textureMapping.cpp
g++ -o textureMapping textureMapping.cpp -L/usr/local/lib -I/usr/local/include -lopencv_core -lopencv_highgui -framework GLUT -framework OpenGL -framework Cocoa -framework IOKit -framework CoreVideo
【问题讨论】：
-
你不能那样做映射。您需要使用投影纹理空间来定义投影纹理映射。 This page 解释问题和解决方案。