Here it is. Not so minimal, but hard to make it short when using the programmable pipeline...
On my computer, if I comment out the push/pop surrounding the sfml code and uncomment the push/pop/reset, then I can see the sfml drawings. I can see the opengl drawing in any case.
#include <GL/glew.h>
#include <SFML/Graphics.hpp>
int main()
{
const int POSITION_ATTRIBUTE_INDEX = 0;
const int width = 800;
const int height = 600;
sf::RenderWindow window(sf::VideoMode(width, height), "SFML!");
glewInit();
////window.pushGLStates();
// compile vertex shader source
const char* vertexShaderSource =
"#version 330\n\
uniform mat4 mvpMatrix;\
uniform vec4 color;\
in vec3 vpos;\
out vec4 vcolor;\
void main(void) {\
gl_Position = mvpMatrix * vec4(vpos, 1.0f);\
vcolor = color;\
}";
int vertexShaderSourceLength = strlen(vertexShaderSource);
GLuint vertexShaderId = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShaderId, 1, &vertexShaderSource, &vertexShaderSourceLength);
glCompileShader(vertexShaderId);
// compile fragment shader source
const GLchar* fragmentShaderSource =
"#version 330\n\
in vec4 vcolor;\
out vec4 fcolor;\
void main(void) {\
fcolor = vcolor;\
}";
int fragmentShaderSourceLength = strlen(fragmentShaderSource);
GLuint fragmentShaderId = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShaderId, 1, &fragmentShaderSource, &fragmentShaderSourceLength);
glCompileShader(fragmentShaderId);
// link shader program
GLuint programId = glCreateProgram();
glAttachShader(programId, vertexShaderId);
glAttachShader(programId, fragmentShaderId);
glBindAttribLocation(programId, POSITION_ATTRIBUTE_INDEX, "position");
glLinkProgram(programId);
// create the triangle vertex buffer
GLuint trianglesId;
float triangleVertices[] = {
-0.5f, -0.5f, 0.0f,
1.0f, -0.5f, 0.0f,
-0.5f, 1.0f, 0.0f
};
glGenBuffers(1, &trianglesId);
glBindBuffer(GL_ARRAY_BUFFER, trianglesId);
glBufferData(GL_ARRAY_BUFFER, sizeof(triangleVertices), triangleVertices, GL_STATIC_DRAW);
// defines the orthographic projection matrix
float m[16];
const float left = -1.5f;
const float right = 1.5f;
const float bottom = -1.5f;
const float top = 1.5f;
const float nearPlane = 1.0f;
const float farPlane = -1.0f;
m[0] = 2 / (right - left);
m[1] = 0.0f;
m[2] = 0.0f;
m[3] = 0.0f;
m[4] = 0.0f;
m[5] = 2 / (top - bottom);
m[6] = 0.0f;
m[7] = 0.0f;
m[8] = 0.0f;
m[9] = 0.0f;
m[10] = 2 / (farPlane - nearPlane);
m[11] = 0.0f;
m[12] = -(right + left) / (right - left);
m[13] = -(top + bottom) / (top - bottom);
m[14] = -(farPlane + nearPlane) / (farPlane - nearPlane);
m[15] = 1.0f;
////window.popGLStates();
bool running = true;
while (running)
{
sf::Event event;
while (window.pollEvent(event))
{
if (event.type == sf::Event::Closed)
running = false;
}
window.clear();
////////window.resetGLStates();
window.pushGLStates();
sf::CircleShape shape(200.f);
shape.setFillColor(sf::Color::Green);
window.draw(shape);
window.popGLStates();
////////window.pushGLStates();
glUseProgram(programId);
GLuint matrixUniform = glGetUniformLocation(programId, "mvpMatrix");
glUniformMatrix4fv(matrixUniform, 1, false, m);
GLuint color = glGetUniformLocation(programId, "color");
glUniform4f(color, 1.0f, 1.0f, 0.0f, 0.7f);
glEnableVertexAttribArray(POSITION_ATTRIBUTE_INDEX);
glBindBuffer(GL_ARRAY_BUFFER, trianglesId);
glVertexAttribPointer(POSITION_ATTRIBUTE_INDEX, 3, GL_FLOAT, GL_FALSE, 0, 0);
glDrawArrays(GL_TRIANGLES, 0, 3);
glDisableVertexAttribArray(POSITION_ATTRIBUTE_INDEX);
////////window.popGLStates();
window.display();
}
return 0;
}
