Add an FFT convolution effect.

[movit] / util.cpp

diff --git a/util.cpp b/util.cpp
index 9e18e9f71cd4999ddbbda88cf38f4a2568c4d485..310e7be7f6627bf58fc5f5556712eafab4a3fa3f 100644 (file)
--- a/util.cpp
+++ b/util.cpp
@@ -178,4 +178,59 @@ void combine_two_samples(float w1, float w2, float *offset, float *total_weight,
        assert(*offset <= 1.0f);
 }
 
+GLuint fill_vertex_attribute(GLuint glsl_program_num, const string &attribute_name, GLint size, GLenum type, GLsizeiptr data_size, const GLvoid *data)
+{
+       int attrib = glGetAttribLocation(glsl_program_num, attribute_name.c_str());
+       if (attrib == -1) {
+               return -1;
+       }
+
+       GLuint vbo;
+       glGenBuffers(1, &vbo);
+       check_error();
+       glBindBuffer(GL_ARRAY_BUFFER, vbo);
+       check_error();
+       glBufferData(GL_ARRAY_BUFFER, data_size, data, GL_STATIC_DRAW);
+       check_error();
+       glEnableVertexAttribArray(attrib);
+       check_error();
+       glVertexAttribPointer(attrib, size, type, GL_FALSE, 0, BUFFER_OFFSET(0));
+       check_error();
+       glBindBuffer(GL_ARRAY_BUFFER, 0);
+       check_error();
+
+       return vbo;
+}
+
+void cleanup_vertex_attribute(GLuint glsl_program_num, const string &attribute_name, GLuint vbo)
+{
+       int attrib = glGetAttribLocation(glsl_program_num, attribute_name.c_str());
+       if (attrib == -1) {
+               return;
+       }
+
+       glDisableVertexAttribArray(attrib);
+       check_error();
+       glDeleteBuffers(1, &vbo);
+       check_error();
+}
+
+unsigned div_round_up(unsigned a, unsigned b)
+{
+       return (a + b - 1) / b;
+}
+
+// Algorithm from http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2.
+unsigned next_power_of_two(unsigned v)
+{
+       v--;
+       v |= v >> 1;
+       v |= v >> 2;
+       v |= v >> 4;
+       v |= v >> 8;
+       v |= v >> 16;
+       v++;
+       return v;
+}
+
 }  // namespace movit