Question

我已经用顶点（2x位置，2x大小，4x uv，2x纹理数据（1个float设置了正确的纹理数组，并设置了2个数组中的纹理索引））填充了VBO，仍然没有渲染，我还缺少什么？

我尝试设置几何着色器以渲染简单的四边形，什么都没有显示，我只尝试渲染片段中的颜色，什么都没有显示，我检查了OPENGL调试消息，那里什么都没有，在顶点着色器中，我检查了矩阵的计算，一切都应该很好

使用glBufferData每帧将数据加载到相同的缓冲区，由于调整大小，此代码用于实体，并且它们在屏幕上的数量可以轻松更改。

片段着色器：

void main()
{
    texColor = vec4(1.0,0.0,0.0,1.0); //Red fillment
    FragColor = texColor;
}

顶点着色器：

布局：

layout(location = 0) in vec2 position;
layout(location = 1) in vec2 size;
layout(location = 2) in vec4 uv;
layout(location = 3) in vec2 textureData; //1. data is to pick correct atlas, 2. is index of texture in atlas

界面：

out VS_OUT
{
    mat4 screenMatrix;
    vec2 position;
    vec4 uv;
    vec2 textureData;
    vec2 size;
} vs_out;

矩阵：

mat4 screenMatrix = mat4((2.0/screenRatio.x),0.0,0.0,0.0,0.0,(2.0/screenRatio.y),0.0,0.0,0.0,0.0,1.0,0.0,0.0,0.0,0.0,1.0);

几何着色器：

布局：

layout (points) in;
layout(triangle_strip,max_vertices = 4) out;

退出：

out vec2 TexData;
out vec2 TexCoord;

代码：

void renderPlayer(mat4 screenMatrix, vec4 position,vec2 textureData,vec2 size,vec4 uv)
{
    gl_Position = nullPos+((position+vec4(0.0,0.0,0.0,0.0))*screenMatrix); // 1:bottom-left
    TexData = textureData;
    TexCoord = vec2(uv.xy);
    EmitVertex();
    gl_Position = nullPos+((position+vec4(size.x,0.0,0.0,0.0))*screenMatrix); // 2:bottom-right
    TexData = textureData;
    TexCoord = vec2(uv.zy);
    EmitVertex();
    gl_Position = nullPos+((position+vec4(0.0,size.y,0.0,0.0))*screenMatrix); // 3:top-left
    TexData = textureData;
    TexCoord = vec2(uv.xw);
    EmitVertex();
    gl_Position = nullPos+((position+vec4(size.x,size.y,0.0,0.0))*screenMatrix);  // 4:top-right 
    TexData = textureData;
    TexCoord = vec2(uv.zw);
    EmitVertex();
    EndPrimitive();
}

主要：

void main() {    
    renderPlayer(gs_in[0].screenMatrix,vec4(gs_in[0].position,0.0,0.0),gs_in[0].textureData,gs_in[0].size,gs_in[0].uv);
}

C ++代码：

VBO数据初始化：

float* vertices = new float[totalVertices];
    for (EntityRenderData renderDataCurrent : renderData)
    {
        for (int layerI = 0; layerI < renderDataCurrent.getLayerCount(); layerI++)
        {
            int i = 0;
            vertices[layerI * 10 + i++] = renderDataCurrent.getLayer(layerI).xPos;
            vertices[layerI * 10 + i++] = renderDataCurrent.getLayer(layerI).yPos;
            vertices[layerI * 10 + i++] = renderDataCurrent.getLayer(layerI).xSize;
            vertices[layerI * 10 + i++] = renderDataCurrent.getLayer(layerI).ySize;
            vertices[layerI * 10 + i++] = renderDataCurrent.getLayer(layerI).U0;
            vertices[layerI * 10 + i++] = renderDataCurrent.getLayer(layerI).V0;
            vertices[layerI * 10 + i++] = renderDataCurrent.getLayer(layerI).U1;
            vertices[layerI * 10 + i++] = renderDataCurrent.getLayer(layerI).V1;
            vertices[layerI * 10 + i++] = (float)renderDataCurrent.getLayer(layerI).textureAtlasId;
            vertices[layerI * 10 + i++] = (float)renderDataCurrent.getLayer(layerI).textureIndex;
            drawCount++;
        }
    }

渲染部分：

    glBindVertexArray(playerVAO);
    glBindBuffer(GL_ARRAY_BUFFER, playerVBO);
    glBufferData(GL_ARRAY_BUFFER, totalVertices * sizeof(float), vertices, GL_STREAM_DRAW);
    game->renderer->entityShader->use();
    glDrawArrays(GL_POINTS, 0, drawCount);

初始化部分：

glGenVertexArrays(1, &playerVAO);
    glGenBuffers(1, &playerVBO);

    glBindVertexArray(playerVAO);
    // position
    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 10 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    // size
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 10 * sizeof(float), (void*)(2 * sizeof(float)));
    glEnableVertexAttribArray(1);
    // uv
    glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, 10 * sizeof(float), (void*)(4 * sizeof(float)));
glEnableVertexAttribArray(2);
    // texture data
    glVertexAttribPointer(3, 2, GL_FLOAT, GL_FALSE, 10 * sizeof(float), (void*)(8 * sizeof(float)));
    glEnableVertexAttribArray(3);

Answer 1

如果绑定了一个非零命名数组缓冲区对象，则glVertexAttribPointer的最后一个参数将被视为缓冲区对象数据存储区中的字节偏移量。 Vertex Array Object中说明了通用顶点属性数据和引用缓冲区的定义。

仅使用glVertexAttribPointer时，生成缓冲区对象是不够的，数组缓冲区对象必须是当前绑定的缓冲区对象：

glGenVertexArrays(1, &playerVAO);
glGenBuffers(1, &playerVBO);

glBindVertexArray(playerVAO);

glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glEnableVertexAttribArray(2);
glEnableVertexAttribArray(3);

glBindBuffer(GL_ARRAY_BUFFER, playerVBO); // <--- bind the buffer object

glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 10 * sizeof(float), (void*)0);
glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 10 * sizeof(float), (void*)(2 * sizeof(float)));
glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, 10 * sizeof(float), (void*)(4 * sizeof(float)));
glVertexAttribPointer(3, 2, GL_FLOAT, GL_FALSE, 10 * sizeof(float), (void*)(8 * sizeof(float)));

GLSL Shader不渲染任何东西，VAO填充，VBO填充顶点

1 个答案: