[英]How to send data to vertex shader with OpenGL?
將數據發送到頂點着色器時遇到一些問題:
#version 450 core
layout (location = 5) in vec3 in_Vertex;
layout (location = 6) in vec3 in_Color;
in int gl_InstanceID;
layout (location = 0) uniform mat4 projection;
layout (location = 1) uniform mat4 modelview;
layout (location = 2) uniform float posX;
layout (location = 3) uniform float posY;
layout (location = 4) uniform uint posZ;
out vec4 v_color;
void main()
{
float tmpX = posX;
float tmpY = posY;
uint tmpZ = posZ;
gl_Position = projection * modelview * vec4(in_Vertex.x + tmpX*2, in_Vertex.y + tmpY*2, in_Vertex.z + tmpZ, 1.0) + vec4(in_Color, 0.0);
v_color = vec4(in_Color,1.0);
}
in_Vertex工作正常,但是in_Color似乎值不正確,我將數據發送為:
glUseProgram(m_shaderPerso.getID());
glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
glVertexAttribPointer(5, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
glEnableVertexAttribArray(5);
glVertexAttribPointer(6, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(m_offsetColor));
glEnableVertexAttribArray(6);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ibo);
glUniformMatrix4fv(0, 1, GL_FALSE, glm::value_ptr(projection));
glUniformMatrix4fv(1, 1, GL_FALSE, glm::value_ptr(modelview));
for( auto &x : m_mapPos)
{
glUniform1f(2, x.second.getX());
glUniform1f(3, x.second.getY());
glUniform1ui(4, s_map->getHauteur(x.second.getXint(),x.second.getYint()));
glDrawElements(GL_TRIANGLES, m_tailleI, GL_UNSIGNED_BYTE, 0);
}
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
glDisableVertexAttribArray(6);
glDisableVertexAttribArray(5);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glUseProgram(m_shaderPerso.getID());
我用以下命令初始化VBO:
glGenBuffers(1, &m_vbo);
glBindBuffer(GL_ARRAY_BUFFER, m_vbo); //Verrouillage VBO
glBufferData(GL_ARRAY_BUFFER, (tailleV * sizeof(float)) + (m_tailleI*3 * sizeof(float)), 0, GL_STATIC_DRAW); //Allocation memoire
glBufferSubData(GL_ARRAY_BUFFER, 0, tailleV * sizeof(float), m_vertices); //Transfert données vertices
glBufferSubData(GL_ARRAY_BUFFER, tailleV * sizeof(float), m_tailleI*3 * sizeof(float), m_color); //Transfert données couleurs
glBindBuffer(GL_ARRAY_BUFFER, 0);
glGenBuffers(1, &m_ibo); //Generation IBO (indices)
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_ibo); //Verrouillage IBO
glBufferData(GL_ELEMENT_ARRAY_BUFFER, m_tailleI * sizeof(GLubyte), 0, GL_STATIC_DRAW); //Allocation memoire
glBufferSubData(GL_ELEMENT_ARRAY_BUFFER, 0, m_tailleI * sizeof(GLubyte), m_indices); //Transfert données
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
我真的不知道我的錯誤在哪里,所以我給了你所有可能有用的代碼。 我確實知道正確地初始化了數組m_vertices,m_color和m_indices,並且正確顯示了頂點,因此頂點和索引的VBO在VRAM中很好。 當我發送數據時,我可能做錯了,但兩天都找不到了,我認為新的外觀可能會對我有所幫助。
感謝您的閱讀和幫助:)
除了@HolyBlackCat所說的以外,您還在混合模式和批處理模式混合使用 。 當您填充緩沖區時,您正在使用批處理模式:
glBindBuffer(GL_ARRAY_BUFFER, m_vbo); //Verrouillage VBO
glBufferData(GL_ARRAY_BUFFER, (tailleV * sizeof(float)) + (m_tailleI*3 * sizeof(float)), 0, GL_STATIC_DRAW); //Allocation memoire
glBufferSubData(GL_ARRAY_BUFFER, 0, tailleV * sizeof(float), m_vertices); //Transfert données vertices
glBufferSubData(GL_ARRAY_BUFFER, tailleV * sizeof(float), m_tailleI*3 * sizeof(float), m_color); //Transfert données couleurs
首先,您要填充頂點,然后在緩沖區的末尾填充顏色屬性。
但是,當您使用緩沖區時,將以交錯模式使用它*:
glVertexAttribPointer(5, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0));
glVertexAttribPointer(6, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(m_offsetColor));
選擇一個並堅持下去。
*在glVertexAttribPointer
函數中, stride
值可能不正確。
您可能可以通過以下方式解決問題:
glVertexAttribPointer(6, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(m_offsetColor))
至:
glVertexAttribPointer(6, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), BUFFER_OFFSET(tailleV * sizeof(float)))
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