When a shader fails compilation, add some line numbers.
[movit] / util.cpp
index d500399..9b01882 100644 (file)
--- a/util.cpp
+++ b/util.cpp
@@ -89,7 +89,7 @@ string read_file(const string &filename)
        const string full_pathname = *movit_data_directory + "/" + filename;
 
        FILE *fp = fopen(full_pathname.c_str(), "r");
-       if (fp == NULL) {
+       if (fp == nullptr) {
                perror(full_pathname.c_str());
                exit(1);
        }
@@ -157,7 +157,19 @@ GLuint compile_shader(const string &shader_src, GLenum type)
        GLint status;
        glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
        if (status == GL_FALSE) {
-               fprintf(stderr, "Failed to compile shader: %s\n", shader_src.c_str());
+               // Add some line numbers to easier identify compile errors.
+               string src_with_lines = "/*   1 */ ";
+               size_t lineno = 1;
+               for (char ch : shader_src) {
+                       src_with_lines.push_back(ch);
+                       if (ch == '\n') {
+                               char buf[32];
+                               snprintf(buf, sizeof(buf), "/* %3zu */ ", ++lineno);
+                               src_with_lines += buf;
+                       }
+               }
+
+               fprintf(stderr, "Failed to compile shader:\n%s\n", src_with_lines.c_str());
                exit(1);
        }
 
@@ -219,59 +231,21 @@ string output_glsl_vec3(const string &name, float x, float y, float z)
        return ss.str();
 }
 
-template<class DestFloat>
-void combine_two_samples(float w1, float w2, float pos1, float pos2, float num_subtexels, float inv_num_subtexels,
-                         DestFloat *offset, DestFloat *total_weight, float *sum_sq_error)
+GLuint generate_vbo(GLint size, GLenum type, GLsizeiptr data_size, const GLvoid *data)
 {
-       assert(movit_initialized);
-       assert(w1 * w2 >= 0.0f);  // Should not have differing signs.
-       float z;  // Normalized 0..1 between pos1 and pos2.
-       if (fabs(w1 + w2) < 1e-6) {
-               z = 0.5f;
-       } else {
-               z = w2 / (w1 + w2);
-       }
+       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();
+       glBindBuffer(GL_ARRAY_BUFFER, 0);
+       check_error();
 
-       // Round to the desired precision. Note that this might take z outside the 0..1 range.
-       *offset = from_fp64<DestFloat>(pos1 + z * (pos2 - pos1));
-       z = (to_fp64(*offset) - pos1) / (pos2 - pos1);
-
-       // Round to the minimum number of bits we have measured earlier.
-       // The card will do this for us anyway, but if we know what the real z
-       // is, we can pick a better total_weight below.
-       z = lrintf(z * num_subtexels) * inv_num_subtexels;
-       
-       // Choose total weight w so that we minimize total squared error
-       // for the effective weights:
-       //
-       //   e = (w(1-z) - a)² + (wz - b)²
-       //
-       // Differentiating by w and setting equal to zero:
-       //
-       //   2(w(1-z) - a)(1-z) + 2(wz - b)z = 0
-       //   w(1-z)² - a(1-z) + wz² - bz = 0
-       //   w((1-z)² + z²) = a(1-z) + bz
-       //   w = (a(1-z) + bz) / ((1-z)² + z²)
-       //
-       // If z had infinite precision, this would simply reduce to w = w1 + w2.
-       *total_weight = from_fp64<DestFloat>((w1 + z * (w2 - w1)) / (z * z + (1 - z) * (1 - z)));
-
-       if (sum_sq_error != NULL) {
-               float err1 = to_fp64(*total_weight) * (1 - z) - w1;
-               float err2 = to_fp64(*total_weight) * z - w2;
-               *sum_sq_error = err1 * err1 + err2 * err2;
-       }
+       return vbo;
 }
 
-// Explicit instantiations.
-template
-void combine_two_samples<float>(float w1, float w2, float pos1, float pos2, float num_subtexels, float inv_num_subtexels,
-                                float *offset, float *total_weight, float *sum_sq_error);
-
-template
-void combine_two_samples<fp16_int_t>(float w1, float w2, float pos1, float pos2, float num_subtexels, float inv_num_subtexels,
-                                     fp16_int_t *offset, fp16_int_t *total_weight, float *sum_sq_error);
-
 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());
@@ -279,13 +253,10 @@ GLuint fill_vertex_attribute(GLuint glsl_program_num, const string &attribute_na
                return -1;
        }
 
-       GLuint vbo;
-       glGenBuffers(1, &vbo);
-       check_error();
+       GLuint vbo = generate_vbo(size, type, data_size, data);
+
        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));
@@ -335,11 +306,46 @@ void *get_gl_context_identifier()
        return (void *)wglGetCurrentContext();
 #else
        void *ret = (void *)eglGetCurrentContext();
-       if (ret != NULL) {
+       if (ret != nullptr) {
                return ret;
        }
        return (void *)glXGetCurrentContext();
 #endif
 }
 
+void abort_gl_error(GLenum err, const char *filename, int line)
+{
+       const char *err_text = "unknown";
+
+       // All errors listed in the glGetError(3G) man page.
+       switch (err) {
+       case GL_NO_ERROR:
+               err_text = "GL_NO_ERROR";  // Should not happen.
+               break;
+       case GL_INVALID_ENUM:
+               err_text = "GL_INVALID_ENUM";
+               break;
+       case GL_INVALID_VALUE:
+               err_text = "GL_INVALID_VALUE";
+               break;
+       case GL_INVALID_OPERATION:
+               err_text = "GL_INVALID_OPERATION";
+               break;
+       case GL_INVALID_FRAMEBUFFER_OPERATION:
+               err_text = "GL_INVALID_FRAMEBUFFER_OPERATION";
+               break;
+       case GL_OUT_OF_MEMORY:
+               err_text = "GL_OUT_OF_MEMORY";
+               break;
+       case GL_STACK_UNDERFLOW:
+               err_text = "GL_STACK_UNDERFLOW";
+               break;
+       case GL_STACK_OVERFLOW:
+               err_text = "GL_STACK_OVERFLOW";
+               break;
+       }
+       fprintf(stderr, "GL error 0x%x (%s) at %s:%d\n", err, err_text, filename, line);
+       abort();
+}
+
 }  // namespace movit