Emulate glReadPixels of GL_ALPHA.

[movit] / util.h

diff --git a/util.h b/util.h
index 5839e5b6c4ce1ccd52ac65f2364a9d6c1e095663..6def56d87614a68454a45d45182e577cf612246f 100644 (file)
--- a/util.h
+++ b/util.h
@@ -1,9 +1,9 @@
-#ifndef _UTIL_H
-#define _UTIL_H 1
+#ifndef _MOVIT_UTIL_H
+#define _MOVIT_UTIL_H 1
 
 // Various utilities.
 
-#include <GL/glew.h>
+#include <epoxy/gl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <Eigen/Core>
@@ -11,6 +11,8 @@
 
 #define BUFFER_OFFSET(i) ((char *)NULL + (i))
 
+namespace movit {
+
 // Converts a HSV color to RGB. Assumes h in [0, 2pi> or [-pi, pi>
 void hsv2rgb(float h, float s, float v, float *r, float *g, float *b);
 
@@ -32,6 +34,9 @@ void print_3x3_matrix(const Eigen::Matrix3d &m);
 // Output a GLSL 3x3 matrix declaration.
 std::string output_glsl_mat3(const std::string &name, const Eigen::Matrix3d &m);
 
+// Calculate a / b, rounding up. Does not handle overflow correctly.
+unsigned div_round_up(unsigned a, unsigned b);
+
 // Calculate where to sample, and with what weight, if one wants to use
 // the GPU's bilinear hardware to sample w1 * x[0] + w2 * x[1].
 //
@@ -41,16 +46,28 @@ std::string output_glsl_mat3(const std::string &name, const Eigen::Matrix3d &m);
 // (estimated) squared errors of the two weights.
 void combine_two_samples(float w1, float w2, float *offset, float *total_weight, float *sum_sq_error);
 
+// Create a VBO with the given data, and bind it to the vertex attribute
+// with name <attribute_name>. Returns the VBO number.
+GLuint fill_vertex_attribute(GLuint glsl_program_num, const std::string &attribute_name, GLint size, GLenum type, GLsizeiptr data_size, const GLvoid *data);
+
+// Clean up after fill_vertex_attribute().
+void cleanup_vertex_attribute(GLuint glsl_program_num, const std::string &attribute_name, GLuint vbo);
+
+// If v is not already a power of two, return the first higher power of two.
+unsigned next_power_of_two(unsigned v);
+
+// Get a pointer that represents the current OpenGL context, in a cross-platform way.
+// This is not intended for anything but identification (ie., so you can associate
+// different FBOs with different contexts); you should probably not try to cast it
+// back into anything you intend to pass into OpenGL.
+void *get_gl_context_identifier();
+
+}  // namespace movit
+
 #ifdef NDEBUG
 #define check_error()
 #else
-#define check_error() { int err = glGetError(); if (err != GL_NO_ERROR) { printf("GL error 0x%x at %s:%d\n", err, __FILE__, __LINE__); exit(1); } }
-#endif
-
-#ifdef __GNUC__
-#define MUST_CHECK_RESULT __attribute__((warn_unused_result))
-#else
-#define MUST_CHECK_RESULT 
+#define check_error() { int err = glGetError(); if (err != GL_NO_ERROR) { printf("GL error 0x%x at %s:%d\n", err, __FILE__, __LINE__); abort(); } }
 #endif
 
 // CHECK() is like assert(), but retains any side effects no matter the compilation mode.
@@ -60,4 +77,4 @@ void combine_two_samples(float w1, float w2, float *offset, float *total_weight,
 #define CHECK(x) do { bool ok = x; if (!ok) { fprintf(stderr, "%s:%d: %s: Assertion `%s' failed.\n", __FILE__, __LINE__, __PRETTY_FUNCTION__, #x); abort(); } } while (false)
 #endif
 
-#endif // !defined(_UTIL_H)
+#endif // !defined(_MOVIT_UTIL_H)