diff options
Diffstat (limited to 'examples')
| -rw-r--r-- | examples/OpenGL3test.cxx | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/examples/OpenGL3test.cxx b/examples/OpenGL3test.cxx index 40d0bf74e..d9216c4a3 100644 --- a/examples/OpenGL3test.cxx +++ b/examples/OpenGL3test.cxx @@ -30,7 +30,7 @@ # endif # include <GL/glew.h> #endif - +#include <FL/gl.h> // for gl_texture_reset() void add_output(const char *format, ...); @@ -50,8 +50,7 @@ public: gl_version_major = 0; } void draw(void) { - if (gl_version_major < 3) return; - if (!shaderProgram) { + if (gl_version_major >= 3 && !shaderProgram) { GLuint vs; GLuint fs; int Mslv, mslv; // major and minor version numbers of the shading language @@ -135,9 +134,11 @@ public: } glClearColor(0.08, 0.8, 0.8, 1.0); glClear(GL_COLOR_BUFFER_BIT); - GLfloat p[]={0,0}; - glUniform2fv(positionUniform, 1, (const GLfloat *)&p); - glDrawArrays(GL_TRIANGLE_FAN, 0, 4); + if (shaderProgram) { + GLfloat p[]={0,0}; + glUniform2fv(positionUniform, 1, (const GLfloat *)&p); + glDrawArrays(GL_TRIANGLE_FAN, 0, 4); + } Fl_Gl_Window::draw(); // Draw FLTK child widgets. } virtual int handle(int event) { @@ -158,7 +159,12 @@ public: const uchar *glv = glGetString(GL_VERSION); add_output("GL_VERSION=%s\n", glv); sscanf((const char *)glv, "%d", &gl_version_major); - if (gl_version_major < 3) add_output("\nThis platform does not support OpenGL V3\n\n"); + if (gl_version_major < 3) { + add_output("\nThis platform does not support OpenGL V3 :\n" + "FLTK widgets will appear but the programmed " + "rendering pipeline will not run.\n"); + mode(mode() & !FL_OPENGL3); + } redraw(); } @@ -181,7 +187,7 @@ public: } return retval; } - void reset(void) { shaderProgram = 0; } + void reset(void) { shaderProgram = 0; gl_texture_reset(); } }; |