月火水木金土日
GLSLでマルチテクスチャ
#include <iostream> #include <Windows.h> #include "prepare_shader.hpp" #include <gl/GL.h> #include <gl/GLU.h> #include <gl/freeglut.h> #pragma comment(lib,"glew32.lib") //ウィンドウの幅と高さ int width, height; GLuint buf_points; GLuint buf_tcoord; GLuint textureID22; GLuint textureID44; GLfloat mproj[16]; GLfloat mmodel[16]; GLuint programID;
void texture_setting(GLuint* texid, std::vector < GLubyte >& texdata, int TEXWIDTH, int TEXHEIGHT) { glGenTextures(1, texid); glBindTexture(GL_TEXTURE_2D, *texid); glPixelStorei(GL_UNPACK_ALIGNMENT, 1); // テクスチャの割り当て glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, TEXWIDTH, TEXHEIGHT, 0, GL_RGB, GL_UNSIGNED_BYTE, texdata.data()); // テクスチャを拡大・縮小する方法の指定 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); } // テクスチャ作成 void create_texture_22() {
std::vector < GLubyte > texdata;
push_3(texdata, 255, 0, 0); push_3(texdata, 0, 255, 0); push_3(texdata, 255, 255, 255); push_3(texdata, 0, 255, 255); texture_setting(&textureID22, texdata, 2, 2); texdata.clear(); } void create_texture_44() { std::vector < GLubyte > texdata;
push_3(texdata, 255, 0, 0); push_3(texdata, 0, 0, 0); push_3(texdata, 255, 0, 0); push_3(texdata, 0, 0, 0); push_3(texdata, 0, 0, 0); push_3(texdata, 255, 0, 0); push_3(texdata, 0, 0, 0); push_3(texdata, 255, 0, 0); push_3(texdata, 255, 0, 0); push_3(texdata, 0, 0, 0); push_3(texdata, 255, 0, 0); push_3(texdata, 0, 0, 0); push_3(texdata, 0, 0, 0); push_3(texdata, 255, 0, 0); push_3(texdata, 0, 0, 0); push_3(texdata, 255, 0, 0); texture_setting(&textureID44, texdata, 4, 4); texdata.clear(); }
// シェーダとデータの設定 void init() { ///////////////////////////////////////////// std::vector<GLfloat> points; GLfloat v = 0.8; push_3(points, -v , -v , 0); push_3(points, v , -v , 0); push_3(points, -v , v , 0); push_3(points, v , v , 0); prepare_buffer(&buf_points, points.data(), points.size() * sizeof(GLfloat), GL_STATIC_DRAW); ///////////////////////////////////////////// // テクスチャ座標 std::vector<GLfloat> texcoord; push_2(texcoord, 0, 0); push_2(texcoord, 1, 0); push_2(texcoord, 0, 1); push_2(texcoord, 1, 1); prepare_buffer(&buf_tcoord, texcoord.data(), texcoord.size() * sizeof(GLfloat), GL_STATIC_DRAW); ///////////////////////////////////////////// //テクスチャ（画像）作成 create_texture_22(); create_texture_44(); ///////////////////////////////////////////// GLuint vtxShader; GLuint flagShaderR; const char* vtxfile = "default.vert"; const char* fragfileR = "default.frag"; std::string verr; std::string ferr; prepare_shader_byfile(&vtxShader, GL_VERTEX_SHADER, vtxfile, &verr); prepare_shader_byfile(&flagShaderR, GL_FRAGMENT_SHADER, fragfileR, &ferr); std::cout << verr << std::endl; std::cout << ferr << std::endl; std::string linkerr; link_program(&programID, { vtxShader ,flagShaderR }, nullptr, &linkerr); loadidentity44(mproj); loadidentity44(mmodel); }
//描画関数 void disp(void) { glViewport(0, 0, width, height); glClearColor(0.2, 0.2, 0.2, 1); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glUseProgram(programID); GLuint loc_ModelViewMatrix = glGetUniformLocation(programID, "ModelViewMatrix"); GLuint loc_ProjectionMatrix = glGetUniformLocation(programID, "ProjectionMatrix"); glUniformMatrix4fv(loc_ModelViewMatrix, 1, GL_FALSE, mmodel); glUniformMatrix4fv(loc_ProjectionMatrix, 1, GL_FALSE, mproj);
GLint loc_tex22 = glGetUniformLocation(programID, "Tex22"); glUniform1i(loc_tex22, 0);// Texture unit 0 glActiveTexture(GL_TEXTURE0 + 0); // Texture unit 0 glBindTexture(GL_TEXTURE_2D, textureID22); GLint loc_tex44 = glGetUniformLocation(programID, "Tex44"); glUniform1i(loc_tex44, 1);// Texture unit 1 glActiveTexture(GL_TEXTURE0 + 1); // Texture unit 1 glBindTexture(GL_TEXTURE_2D, textureID44);
{ auto bind_points = EnableAndBindFArrayBuffer(0, buf_points, 3, GL_FLOAT); auto bind_tcoord = EnableAndBindFArrayBuffer(1, buf_tcoord, 2, GL_FLOAT); glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); } glUseProgram(0); glFlush(); }
//ウィンドウサイズの変化時に呼び出される void reshape(int w, int h) { width = w; height = h; disp(); } //エントリポイント int main(int argc, char** argv) { glutInit(&argc, argv); glutInitWindowPosition(100, 50); glutInitWindowSize(500, 500); glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA); glutCreateWindow("sample"); glutDisplayFunc(disp); glutReshapeFunc(reshape); glewInit(); init(); glutMainLoop(); return 0; }
シェーダ
default.vert
#version 460 core layout (location = 0) in vec3 aPos;//ポリゴンの頂点座標 layout (location = 1) in vec2 texcd;//座標に対応するテクスチャ座標 out vec2 vTexCoord;//テクスチャ座標の出力先 uniform mat4 gl_ModelViewMatrix; uniform mat4 gl_ProjectionMatrix; void main() { gl_Position = gl_ProjectionMatrix * gl_ModelViewMatrix * vec4(aPos, 1.0); vTexCoord = texcd;//フラグメントシェーダへテクスチャ座標を渡す }
default.frag
#version 460 core out vec4 FragColor;//色の出力先 uniform sampler2D Tex22; uniform sampler2D Tex44; in vec2 vTexCoord;//頂点シェーダから渡されたテクスチャ座標 void main() { //テクスチャデータとテクスチャ座標から色を決定 vec4 c22 = texture(Tex22,vTexCoord); vec4 c44 = texture(Tex44,vTexCoord); //合成したテクスチャの色を作成 vec4 crr; crr.x = c44.x * c22.x; crr.y = c44.x * c22.y; crr.z = c44.x * c22.z; FragColor = crr; }
