窗口大小調整時的模型OpenGL 3.2

Question

我已經在OpenGL 3.2渲染上下文中設置了一個窗口（在MFC中）。既然是OpenGL 3.2，我想使用着色器等，所以我用手繪畫我的投影和查看矩陣。我使用this教程作爲輸入來構建它們並將它們傳遞給我的着色器。

現在的問題是（即使在本教程的示例中）當我調整窗口大小時，模型被拉伸。

這是我用來構建我的矩陣的代碼（我重建它們並在刷新窗口時將它們發送給我的着色器）。

視圖矩陣：

float zAxis[3], xAxis[3], yAxis[3]; 
float length, result1, result2, result3; 

// zAxis = normal(lookAt - position) 
zAxis[0] = lookAt[0] - m_position[0]; 
zAxis[1] = lookAt[1] - m_position[1]; 
zAxis[2] = lookAt[2] - m_position[2]; 
length = sqrt((zAxis[0] * zAxis[0]) + (zAxis[1] * zAxis[1]) + (zAxis[2] * zAxis[2])); 
zAxis[0] = zAxis[0]/length; 
zAxis[1] = zAxis[1]/length; 
zAxis[2] = zAxis[2]/length; 

// xAxis = normal(cross(up, zAxis)) 
xAxis[0] = (up[1] * zAxis[2]) - (up[2] * zAxis[1]); 
xAxis[1] = (up[2] * zAxis[0]) - (up[0] * zAxis[2]); 
xAxis[2] = (up[0] * zAxis[1]) - (up[1] * zAxis[0]); 
length = sqrt((xAxis[0] * xAxis[0]) + (xAxis[1] * xAxis[1]) + (xAxis[2] * xAxis[2])); 
xAxis[0] = xAxis[0]/length; 
xAxis[1] = xAxis[1]/length; 
xAxis[2] = xAxis[2]/length; 

// yAxis = cross(zAxis, xAxis) 
yAxis[0] = (zAxis[1] * xAxis[2]) - (zAxis[2] * xAxis[1]); 
yAxis[1] = (zAxis[2] * xAxis[0]) - (zAxis[0] * xAxis[2]); 
yAxis[2] = (zAxis[0] * xAxis[1]) - (zAxis[1] * xAxis[0]); 

// -dot(xAxis, position) 
result1 = ((xAxis[0] * m_position[0]) + (xAxis[1] * m_position[1]) + (xAxis[2] * m_position[2])) * -1.0f; 

// -dot(yaxis, eye) 
result2 = ((yAxis[0] * m_position[0]) + (yAxis[1] * m_position[1]) + (yAxis[2] * m_position[2])) * -1.0f; 

// -dot(zaxis, eye) 
result3 = ((zAxis[0] * m_position[0]) + (zAxis[1] * m_position[1]) + (zAxis[2] * m_position[2])) * -1.0f; 

viewMatrix[0] = xAxis[0]; 
viewMatrix[1] = yAxis[0]; 
viewMatrix[2] = zAxis[0]; 
viewMatrix[3] = 0.0f; 

viewMatrix[4] = xAxis[1]; 
viewMatrix[5] = yAxis[1]; 
viewMatrix[6] = zAxis[1]; 
viewMatrix[7] = 0.0f; 

viewMatrix[8] = xAxis[2]; 
viewMatrix[9] = yAxis[2]; 
viewMatrix[10] = zAxis[2]; 
viewMatrix[11] = 0.0f; 

viewMatrix[12] = result1; 
viewMatrix[13] = result2; 
viewMatrix[14] = result3; 
viewMatrix[15] = 1.0f; 

投影矩陣：

float screenAspect = (float)rcClient.Width()/(float)rcClient.Height(); 
float fov = 3.14159265358979323846f/4.0f; 
float zfar = 1000.0; 
float znear = 0.1f; 

projectionMatrix[0] = 1.0f/(screenAspect * tan(fov * 0.5f)); 
projectionMatrix[1] = 0.0f; 
projectionMatrix[2] = 0.0f; 
projectionMatrix[3] = 0.0f; 

projectionMatrix[4] = 0.0f; 
projectionMatrix[5] = 1.0f/tan(fov * 0.5f); 
projectionMatrix[6] = 0.0f; 
projectionMatrix[7] = 0.0f; 

projectionMatrix[8] = 0.0f; 
projectionMatrix[9] = 0.0f; 
projectionMatrix[10] = zfar/(zfar - znear); 
projectionMatrix[11] = 1.0f; 

projectionMatrix[12] = 0.0f; 
projectionMatrix[13] = 0.0f; 
projectionMatrix[14] = (-znear * zfar)/(zfar - znear); 
projectionMatrix[15] = 0.0f; 

而在我的着色器我用他們這樣說：

#version 150 

in vec3 inputPosition; 
in vec3 inputColor; 

out vec3 color; 

uniform mat4 worldMatrix; 
uniform mat4 viewMatrix; 
uniform mat4 projectionMatrix; 

void main(void) 
{ 
    gl_Position = projectionMatrix * viewMatrix * worldMatrix * vec4(inputPosition, 1.0f); 

    color = inputColor; 
} 

有沒有人有什麼正在發生的事情的想法這裏？

Answer 1

不要使用glViewport，因爲您可以使用着色器，這是首選方式。

你可以改變你的投影矩陣：

float projectionMatrix[4][4]; 
projectionMatrix[0][0] = 1.0f/(screenAspect * tan(fov * 0.5f)); 
projectionMatrix[0][1] = 0.0f; 
projectionMatrix[0][2] = 0.0f; 
projectionMatrix[0][3] = 0.0f; 

projectionMatrix[1][0] = 0.0f; 
projectionMatrix[1][1] = 1.0f/tan(fov * 0.5f); 
projectionMatrix[1][2] = 0.0f; 
projectionMatrix[1][3] = 0.0f; 

projectionMatrix[2][0] = 0.0f; 
projectionMatrix[2][1] = 0.0f; 
projectionMatrix[2][2] = (-znear -zfar)/(znear-zfar); 
projectionMatrix[2][3] = 2.0f * zfar * znear/(znear-zfar); 

projectionMatrix[3][0] = 0.0f; 
projectionMatrix[3][1] = 0.0f; 
projectionMatrix[3][2] = 1.0; 
projectionMatrix[3][3] = 0.0f; 

我不知道你的UVN矩陣，但因爲你得到了它使用glViewport工作後它可能不是問題。 無論如何，您可以使用GLM而不是生成矩陣。打造的投影，UVN，翻譯矩陣等的代碼示例這裏給出：glm code example 我認爲，這個教程解釋轉換不夠好：http://ogldev.atspace.co.uk/