1 files changed, 197 insertions, 0 deletions
diff --git a/intern/cycles/app/opengl/shader.cpp b/intern/cycles/app/opengl/shader.cpp
new file mode 100644
index 00000000000..9db9ea7fce9
--- /dev/null
+++ b/intern/cycles/app/opengl/shader.cpp
@@ -0,0 +1,197 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright 2011-2022 Blender Foundation */
+
+#include "app/opengl/shader.h"
+
+#include "util/log.h"
+#include "util/string.h"
+
+#include <GL/glew.h>
+
+CCL_NAMESPACE_BEGIN
+
+/* --------------------------------------------------------------------
+ * OpenGLShader.
+ */
+
+static const char *VERTEX_SHADER =
+    "#version 330\n"
+    "uniform vec2 fullscreen;\n"
+    "in vec2 texCoord;\n"
+    "in vec2 pos;\n"
+    "out vec2 texCoord_interp;\n"
+    "\n"
+    "vec2 normalize_coordinates()\n"
+    "{\n"
+    "   return (vec2(2.0) * (pos / fullscreen)) - vec2(1.0);\n"
+    "}\n"
+    "\n"
+    "void main()\n"
+    "{\n"
+    "   gl_Position = vec4(normalize_coordinates(), 0.0, 1.0);\n"
+    "   texCoord_interp = texCoord;\n"
+    "}\n\0";
+
+static const char *FRAGMENT_SHADER =
+    "#version 330\n"
+    "uniform sampler2D image_texture;\n"
+    "in vec2 texCoord_interp;\n"
+    "out vec4 fragColor;\n"
+    "\n"
+    "void main()\n"
+    "{\n"
+    "   vec4 rgba = texture(image_texture, texCoord_interp);\n"
+    /* Harcoded Rec.709 gamma, should use OpenColorIO eventually. */
+    "   fragColor = pow(rgba, vec4(0.45, 0.45, 0.45, 1.0));\n"
+    "}\n\0";
+
+static void shader_print_errors(const char *task, const char *log, const char *code)
+{
+  LOG(ERROR) << "Shader: " << task << " error:";
+  LOG(ERROR) << "===== shader string ====";
+
+  stringstream stream(code);
+  string partial;
+
+  int line = 1;
+  while (getline(stream, partial, '\n')) {
+    if (line < 10) {
+      LOG(ERROR) << " " << line << " " << partial;
+    }
+    else {
+      LOG(ERROR) << line << " " << partial;
+    }
+    line++;
+  }
+  LOG(ERROR) << log;
+}
+
+static int compile_shader_program(void)
+{
+  const struct Shader {
+    const char *source;
+    const GLenum type;
+  } shaders[2] = {{VERTEX_SHADER, GL_VERTEX_SHADER}, {FRAGMENT_SHADER, GL_FRAGMENT_SHADER}};
+
+  const GLuint program = glCreateProgram();
+
+  for (int i = 0; i < 2; i++) {
+    const GLuint shader = glCreateShader(shaders[i].type);
+
+    string source_str = shaders[i].source;
+    const char *c_str = source_str.c_str();
+
+    glShaderSource(shader, 1, &c_str, NULL);
+    glCompileShader(shader);
+
+    GLint compile_status;
+    glGetShaderiv(shader, GL_COMPILE_STATUS, &compile_status);
+
+    if (!compile_status) {
+      GLchar log[5000];
+      GLsizei length = 0;
+      glGetShaderInfoLog(shader, sizeof(log), &length, log);
+      shader_print_errors("compile", log, c_str);
+      return 0;
+    }
+
+    glAttachShader(program, shader);
+  }
+
+  /* Link output. */
+  glBindFragDataLocation(program, 0, "fragColor");
+
+  /* Link and error check. */
+  glLinkProgram(program);
+
+  GLint link_status;
+  glGetProgramiv(program, GL_LINK_STATUS, &link_status);
+  if (!link_status) {
+    GLchar log[5000];
+    GLsizei length = 0;
+    glGetShaderInfoLog(program, sizeof(log), &length, log);
+    shader_print_errors("linking", log, VERTEX_SHADER);
+    shader_print_errors("linking", log, FRAGMENT_SHADER);
+    return 0;
+  }
+
+  return program;
+}
+
+int OpenGLShader::get_position_attrib_location()
+{
+  if (position_attribute_location_ == -1) {
+    const uint shader_program = get_shader_program();
+    position_attribute_location_ = glGetAttribLocation(shader_program, position_attribute_name);
+  }
+  return position_attribute_location_;
+}
+
+int OpenGLShader::get_tex_coord_attrib_location()
+{
+  if (tex_coord_attribute_location_ == -1) {
+    const uint shader_program = get_shader_program();
+    tex_coord_attribute_location_ = glGetAttribLocation(shader_program, tex_coord_attribute_name);
+  }
+  return tex_coord_attribute_location_;
+}
+
+void OpenGLShader::bind(int width, int height)
+{
+  create_shader_if_needed();
+
+  if (!shader_program_) {
+    return;
+  }
+
+  glUseProgram(shader_program_);
+  glUniform1i(image_texture_location_, 0);
+  glUniform2f(fullscreen_location_, width, height);
+}
+
+void OpenGLShader::unbind()
+{
+}
+
+uint OpenGLShader::get_shader_program()
+{
+  return shader_program_;
+}
+
+void OpenGLShader::create_shader_if_needed()
+{
+  if (shader_program_ || shader_compile_attempted_) {
+    return;
+  }
+
+  shader_compile_attempted_ = true;
+
+  shader_program_ = compile_shader_program();
+  if (!shader_program_) {
+    return;
+  }
+
+  glUseProgram(shader_program_);
+
+  image_texture_location_ = glGetUniformLocation(shader_program_, "image_texture");
+  if (image_texture_location_ < 0) {
+    LOG(ERROR) << "Shader doesn't contain the 'image_texture' uniform.";
+    destroy_shader();
+    return;
+  }
+
+  fullscreen_location_ = glGetUniformLocation(shader_program_, "fullscreen");
+  if (fullscreen_location_ < 0) {
+    LOG(ERROR) << "Shader doesn't contain the 'fullscreen' uniform.";
+    destroy_shader();
+    return;
+  }
+}
+
+void OpenGLShader::destroy_shader()
+{
+  glDeleteProgram(shader_program_);
+  shader_program_ = 0;
+}
+
+CCL_NAMESPACE_END