opengl的纹理

这几天晚上一直在想游戏引擎的纹理的处理

可是对这块又不是很熟悉，于是就看看网上的代码，在看看一些本来就有的代码

想着如何才能做出符合自己要求的texture

这不先乱改几下代码吧

 

熟悉点就可以使用了

#include <GL/glut.h> #include <stdlib.h> #include <math.h> #include <stdio.h> GLfloat ctrlpoints[4][4][3] = { {​{ -1.5, -1.5, 4.0}, { -0.5, -1.5, 2.0}, {0.5, -1.5, -1.0}, {1.5, -1.5, 2.0}}, {​{ -1.5, -0.5, 1.0}, { -0.5, -0.5, 3.0}, {0.5, -0.5, 0.0}, {1.5, -0.5, -1.0}}, {​{ -1.5, 0.5, 4.0}, { -0.5, 0.5, 0.0}, {0.5, 0.5, 3.0}, {1.5, 0.5, 4.0}}, {​{ -1.5, 1.5, -2.0}, { -0.5, 1.5, -2.0}, {0.5, 1.5, 0.0}, {1.5, 1.5, -1.0}} }; GLfloat texpts[2][2][2] = {​{​{0.0, 0.0}, {0.0, 1.0}}, {​{1.0, 0.0}, {1.0, 1.0}}}; void display(void) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glColor3f(1.0, 1.0, 1.0); glEvalMesh2(GL_FILL, 0, 20, 0, 20); glFlush(); } #define imageWidth 64 #define imageHeight 64 class texture { public: void makeImage() { int i, j; float ti, tj; for (i = 0; i < imageWidth; i++) { ti = 2.0*3.14159265*i/imageWidth; for (j = 0; j < imageHeight; j++) { tj = 2.0*3.14159265*j/imageHeight; image[3*(imageHeight*i+j)] = (GLubyte) 127*(1.0+sin(ti)); image[3*(imageHeight*i+j)+1] = (GLubyte) 127*(1.0+cos(2*tj)); image[3*(imageHeight*i+j)+2] = (GLubyte) 127*(1.0+cos(ti+tj)); } } } void bind() { glGenTextures(1,&tex[0]); glBindTexture(GL_TEXTURE_2D, tex[0]); } void render() { glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL); 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_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, imageWidth, imageHeight, 0, GL_RGB, GL_UNSIGNED_BYTE, image); } private: GLubyte image[3*imageWidth*imageHeight]; GLuint tex[1]; }; texture te; void init(void) { glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4, 0, 1, 12, 4, &ctrlpoints[0][0][0]); glMap2f(GL_MAP2_TEXTURE_COORD_2, 0, 1, 2, 2, 0, 1, 4, 2, &texpts[0][0][0]); glEnable(GL_MAP2_TEXTURE_COORD_2); glEnable(GL_MAP2_VERTEX_3); glMapGrid2f(20, 0.0, 1.0, 20, 0.0, 1.0); te.makeImage(); te.bind(); te.render(); glEnable(GL_TEXTURE_2D); glEnable(GL_DEPTH_TEST); glShadeModel (GL_FLAT); } void reshape(int w, int h) { glViewport(0, 0, (GLsizei) w, (GLsizei) h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); if (w <= h) glOrtho(-4.0, 4.0, -4.0*(GLfloat)h/(GLfloat)w, 4.0*(GLfloat)h/(GLfloat)w, -4.0, 4.0); else glOrtho(-4.0*(GLfloat)w/(GLfloat)h, 4.0*(GLfloat)w/(GLfloat)h, -4.0, 4.0, -4.0, 4.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glRotatef(85.0, 1.0, 1.0, 1.0); } void keyboard(unsigned char key, int x, int y) { switch (key) { case 27: exit(0); 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); glutKeyboardFunc(keyboard); glutMainLoop(); return 0; }