Question

当不应用任何类型的正投影时，我可以按预期显示两个图像。但是，当我尝试使用glm :: ortho（）向我的顶点添加正交投影矩阵时，我的精灵会消失。我的代码如下（尝试删除不相关的代码）：

Sprite.cpp

Sprite::Sprite()
{
    vboID = 0;
}

Sprite::~Sprite()
{
    //Clean up sprite buffers on GPU when done with sprite
    if (vboID != 0)
        glDeleteBuffers(1, &vboID);
}

void Sprite::Init(float x, float y, float width, float height, Blz::string imageFilePath)
{
    this->x = x;
    this->y = y;
    this->width = width;
    this->height = height;

    if (vboID == 0)
        glGenBuffers(1, &vboID);

    texture = Blz::OpenGL::LoadImage(imageFilePath);

    Vector3D vertexData[6]{
        Vector3D {x + width, y + height, 0.0f},
        Vector3D {x, y + height, 0.0f },
        Vector3D {x, y, 0.0f},
        Vector3D {x, y, 0.0f},
        Vector3D {x + width, y, 0.0f},
        Vector3D {x + width, y + height, 0.0f},
    };

    for (int i = 0; i < 6; ++i)
    {
        vertexData[i].color.r = 0;
        vertexData[i].color.g = 155;
        vertexData[i].color.b = 200;
    };

    vertexData[0].setUV(1.0f, 1.0f);
    vertexData[1].setUV(0.0f, 1.0f);
    vertexData[2].setUV(0.0f, 0.0f);
    vertexData[3].setUV(0.0f, 0.0f);
    vertexData[4].setUV(1.0f, 0.0f);
    vertexData[5].setUV(1.0f, 1.0f);

    glBindBuffer(GL_ARRAY_BUFFER, vboID);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertexData), vertexData, GL_STATIC_DRAW);

    glBindBuffer(GL_ARRAY_BUFFER, 0);
}

void Sprite::Draw()
{
    glBindTexture(GL_TEXTURE_2D, texture.id);
    glBindBuffer(GL_ARRAY_BUFFER, vboID);

    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vector3D), (void*)offsetof(Vector3D, position));
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Vector3D), (void*)offsetof(Vector3D, textCoordinate));

    glDrawArrays(GL_TRIANGLES, 0, 6);

    glBindBuffer(GL_ARRAY_BUFFER, 0);
}

的main.cpp

int main(int agrc, char** argv)
{
    window.Initialize();

    glm::mat4 projectionMatrix = glm::ortho(0.0f, 800.0f, 0.0f, 600.0f, -1.0f, 1.0f);

    p_sprites.push_back(new Sprite());
    p_sprites.back()->Init(0.0f, 0.0f, .5f, .5f, "CharImage.png");

    p_sprites.push_back(new Sprite());
    p_sprites.back()->Init(-0.4f, 0.0f, .5f, .5f, "CharImage.png");

    GameState gamestate{ GameState::PLAY };

    SDL_Event evnt;

    Blz::OpenGL::ShaderProgram colorShaderProgram("Source/GameEngine/Shaders/VertexShader.glsl", "Source/GameEngine/Shaders/FragmentShader.glsl");

    colorShaderProgram.Compile();
    colorShaderProgram.AddAttribute("vertexPosition");
    colorShaderProgram.AddAttribute("textCoord");
    colorShaderProgram.Link();
    colorShaderProgram.Bind();

    //Get uniform from Shader and send texture info to shader
    GLuint uniformLocation = colorShaderProgram.GetUniformLocation("basicTexture");
    glUniform1i(uniformLocation, 0);

    //Get uniform location from shader
    GLuint ProjectMatrixUniformLocation = colorShaderProgram.GetUniformLocation("projectionMatrix");

    while (gamestate != GameState::EXIT)
    {
        ProcessInput();

        //Send down projectionMatrix resulting from glm::ortho() call
        glUniformMatrix4fv(ProjectMatrixUniformLocation, 1, GL_FALSE, &projectionMatrix[0][0]);

        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        for (uint32 i = 0; i < p_sprites.size(); ++i)
            p_sprites[i]->Draw();

        SDL_GL_SwapWindow(window)
    }

    return 0;
}

顶点着色器

#version 430

in vec3 vertexPosition;
in vec2 textCoord;

out vec2 TextureCoord;

uniform mat4 projectionMatrix;

void main()
{
    vec4 position = vec4(vertexPosition, 1.0f);
    gl_Position = projectionMatrix * position;
    TextureCoord = textCoord;
};

片段着色器

#version 430

out vec4 daColor;
in vec2 TextureCoord;

uniform sampler2D basicTexture;

void main()
{
    vec4 texel = texture(basicTexture, TextureCoord);
    daColor = texel;
};

添加glm :: ortho矩阵会导致精灵消失

0 个答案: