1 files changed, 224 insertions, 0 deletions
diff --git a/src/shader/shader.c b/src/shader/shader.c
new file mode 100644
index 0000000..817d451
--- /dev/null
+++ b/src/shader/shader.c
@@ -0,0 +1,224 @@
+#include "shader.h"
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+static honey_result read_file(char** destination, char* file_path) {
+  FILE* f = fopen(file_path, "r");
+  if (f == NULL) {
+    honey_error_set_string1(file_path);
+    return HONEY_FILE_READ_ERROR;
+  }
+
+  fseek(f, 0, SEEK_END);
+  long fsize = ftell(f);
+  fseek(f, 0, SEEK_SET);
+
+  *destination = malloc(fsize + 1);
+  if (*destination == NULL) {
+    return HONEY_MEMORY_ALLOCATION_ERROR;
+  }
+  fread(*destination, 1, fsize, f);
+  fclose(f);
+
+  (*destination)[fsize] = 0;
+
+  return HONEY_OK;
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+honey_result honey_shader_load(honey_shader* shader,
+                              char* vertex_shader_path,
+                              char* fragment_shader_path) {
+  /* load vertex shader code */
+  char* vertex_shader_code;
+  honey_result result = read_file(&vertex_shader_code,
+                                 vertex_shader_path);
+  if (result != HONEY_OK)
+    return result;
+
+  /* load fragment shader code */
+  char* fragment_shader_code;
+  result = read_file(&fragment_shader_code,
+                     fragment_shader_path);
+  if (result != HONEY_OK)
+    return result;
+
+  result = honey_shader_new(shader,
+                            vertex_shader_code,
+                            fragment_shader_code);
+
+  if (result == HONEY_VERTEX_SHADER_COMPILATION_ERROR)
+    honey_error_set_string2(vertex_shader_path);
+
+  if (result == HONEY_FRAGMENT_SHADER_COMPILATION_ERROR)
+    honey_error_set_string2(fragment_shader_path);
+
+  free(vertex_shader_code);
+  free(fragment_shader_code);
+
+  return result;
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+honey_result honey_shader_new(honey_shader* shader,
+                             char* vertex_shader_code,
+                             char* fragment_shader_code) {
+    /* compile shaders */
+  int success;
+  char error[512];
+
+  int vertex_shader = glCreateShader(GL_VERTEX_SHADER);
+  glShaderSource(vertex_shader, 1, ((const char**)&vertex_shader_code), NULL);
+  glCompileShader(vertex_shader);
+  glGetShaderiv(vertex_shader, GL_COMPILE_STATUS, &success);
+  if (!success) {
+    honey_error_clear_strings();
+    char compiler_error[HONEY_ERROR_DATA_STRING_LENGTH];
+    glGetShaderInfoLog(vertex_shader, HONEY_ERROR_DATA_STRING_LENGTH, NULL, compiler_error);
+    honey_error_set_string1(compiler_error);
+    return HONEY_VERTEX_SHADER_COMPILATION_ERROR;
+  }
+
+  int fragment_shader = glCreateShader(GL_FRAGMENT_SHADER);
+  glShaderSource(fragment_shader, 1, ((const char**)&fragment_shader_code), NULL);
+  glCompileShader(fragment_shader);
+  glGetShaderiv(fragment_shader, GL_COMPILE_STATUS, &success);
+  if (!success) {
+    honey_error_clear_strings();
+    char compiler_error[HONEY_ERROR_DATA_STRING_LENGTH];
+    glGetShaderInfoLog(fragment_shader, HONEY_ERROR_DATA_STRING_LENGTH, NULL, compiler_error);
+    honey_error_set_string1(compiler_error);
+    return HONEY_FRAGMENT_SHADER_COMPILATION_ERROR;
+  }
+
+  /* link shaders */
+  *shader = glCreateProgram();
+  glAttachShader(*shader, vertex_shader);
+  glAttachShader(*shader, fragment_shader);
+  glLinkProgram(*shader);
+  glGetShaderiv(*shader, GL_LINK_STATUS, &success);
+  if (!success) {
+    honey_error_clear_strings();
+    char compiler_error[HONEY_ERROR_DATA_STRING_LENGTH];
+    glGetShaderInfoLog(vertex_shader, HONEY_ERROR_DATA_STRING_LENGTH, NULL, compiler_error);
+    honey_error_set_string1(compiler_error);
+    return HONEY_SHADER_LINK_ERROR;
+  }
+
+  glDeleteShader(vertex_shader);
+  glDeleteShader(fragment_shader);
+
+  return HONEY_OK;
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+void honey_shader_set_int(honey_shader shader,
+                          char* int_name,
+                          int value) {
+  honey_shader_use(shader);
+  unsigned int int_location = glGetUniformLocation(shader, int_name);
+  glUniform1i(int_location, value);
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+void honey_shader_set_float(honey_shader shader,
+                            char* float_name,
+                            float value) {
+  honey_shader_use(shader);
+  unsigned int float_location = glGetUniformLocation(shader, float_name);
+  glUniform1f(float_location, value);
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+void honey_shader_set_vec3(honey_shader shader,
+                           char* vector_name,
+                           vec3 value) {
+  honey_shader_use(shader);
+  unsigned int vector_location = glGetUniformLocation(shader, vector_name);
+  glUniform3fv(vector_location, 1, (float*) value);
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+void honey_shader_set_mat3(honey_shader shader,
+                           char* matrix_name,
+                           mat3 value) {
+  glUseProgram(shader);
+  unsigned int matrix_location = glGetUniformLocation(shader, matrix_name);
+  glUniformMatrix3fv(matrix_location, 1, GL_FALSE, (float*) value);
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+void honey_shader_set_mat4(honey_shader shader,
+                           char* matrix_name,
+                           mat4 value) {
+  glUseProgram(shader);
+  unsigned int matrix_location = glGetUniformLocation(shader, matrix_name);
+  glUniformMatrix4fv(matrix_location, 1, GL_FALSE, (float*) value);
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+void honey_shader_set_point_light(honey_shader shader,
+                                  int point_light_index,
+                                  honey_point_light light) {
+  char name[HONEY_MAX_LIGHT_NAME_LENGTH];
+
+  snprintf(name,
+           HONEY_MAX_LIGHT_NAME_LENGTH,
+           "point_lights[%d].position",
+           point_light_index);
+  honey_shader_set_vec3(shader, name, light.position);
+  
+  snprintf(name,
+           HONEY_MAX_LIGHT_NAME_LENGTH,
+           "point_lights[%d].color",
+           point_light_index);
+  honey_shader_set_vec3(shader, name, light.color);
+    
+  snprintf(name,
+           HONEY_MAX_LIGHT_NAME_LENGTH,
+           "point_lights[%d].constant",
+           point_light_index);
+  honey_shader_set_float(shader, name, light.constant);
+
+  snprintf(name,
+           HONEY_MAX_LIGHT_NAME_LENGTH,
+           "point_lights[%d].linear",
+           point_light_index);
+  honey_shader_set_float(shader, name, light.linear);
+
+  snprintf(name,
+           HONEY_MAX_LIGHT_NAME_LENGTH,
+           "point_lights[%d].quadratic",
+           point_light_index);
+  honey_shader_set_float(shader, name, light.quadratic);
+}
+
+/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
+
+void honey_shader_set_directional_light(honey_shader shader,
+                                        int directional_light_index,
+                                        honey_directional_light light) {
+  char name[HONEY_MAX_LIGHT_NAME_LENGTH];
+  
+  snprintf(name,
+           HONEY_MAX_LIGHT_NAME_LENGTH,
+           "directional_lights[%d].direction",
+           directional_light_index);
+  honey_shader_set_vec3(shader, name, light.direction);
+
+  snprintf(name,
+           HONEY_MAX_LIGHT_NAME_LENGTH,
+           "directional_lights[%d].color",
+           directional_light_index);
+  honey_shader_set_vec3(shader, name, light.color);
+}
+
+