chipd8/source/imgui.d

400 lines
15 KiB
D

module imgui;
import glad.gl.all;
import derelict.sdl2.sdl;
import derelict.imgui.imgui;
import window;
import std.traits : isDelegate, ReturnType, ParameterTypeTuple;
auto bindDelegate(T, string file = __FILE__, size_t line = __LINE__)(T t) if(isDelegate!T) {
static T dg;
dg = t;
extern(C) static ReturnType!T func(ParameterTypeTuple!T args) {
return dg(args);
}
return &func;
} // bindDelegate (thanks Destructionator)
struct Imgui {
// OpenGL data, cleanup soon
GLuint font_texture_ = 0;
int shander_handle_ = 0, vs_handle_ = 0, fs_handle_ = 0;
int shader_attrib_loc_tex_ = 0, shader_attrib_loc_projmtx_ = 0;
int shader_attrib_loc_pos_ = 0, shader_attrib_loc_uv_ = 0, shader_attrib_loc_color_ = 0;
uint vao_ = 0, vbo_ = 0, ebo_ = 0;
// imgui input related state
bool[3] mouse_buttons_pressed;
float scroll_wheel = 0.0f;
void initialize() {
auto io = igGetIO();
io.KeyMap[ImGuiKey_Tab] = SDL_SCANCODE_TAB;
io.KeyMap[ImGuiKey_LeftArrow] = SDL_SCANCODE_LEFT;
io.KeyMap[ImGuiKey_RightArrow] = SDL_SCANCODE_RIGHT;
io.KeyMap[ImGuiKey_UpArrow] = SDL_SCANCODE_UP;
io.KeyMap[ImGuiKey_DownArrow] = SDL_SCANCODE_DOWN;
io.KeyMap[ImGuiKey_PageUp] = SDL_SCANCODE_PAGEUP;
io.KeyMap[ImGuiKey_PageDown] = SDL_SCANCODE_PAGEDOWN;
io.KeyMap[ImGuiKey_Home] = SDL_SCANCODE_HOME;
io.KeyMap[ImGuiKey_End] = SDL_SCANCODE_END;
io.KeyMap[ImGuiKey_Delete] = SDL_SCANCODE_DELETE;
io.KeyMap[ImGuiKey_Backspace] = SDL_SCANCODE_BACKSPACE;
io.KeyMap[ImGuiKey_Enter] = SDL_SCANCODE_RETURN;
io.KeyMap[ImGuiKey_Escape] = SDL_SCANCODE_ESCAPE;
io.KeyMap[ImGuiKey_A] = SDL_SCANCODE_A;
io.KeyMap[ImGuiKey_C] = SDL_SCANCODE_C;
io.KeyMap[ImGuiKey_V] = SDL_SCANCODE_V;
io.KeyMap[ImGuiKey_X] = SDL_SCANCODE_X;
io.KeyMap[ImGuiKey_Y] = SDL_SCANCODE_Y;
io.KeyMap[ImGuiKey_Z] = SDL_SCANCODE_Z;
io.RenderDrawListsFn = bindDelegate(&renderDrawLists);
io.SetClipboardTextFn = bindDelegate(&setClipboardText);
io.GetClipboardTextFn = bindDelegate(&getClipboardText);
}
void createFontTexture() {
// build texture atlas
auto io = igGetIO();
ubyte* pixels;
int width, height;
ImFontAtlas_GetTexDataAsRGBA32(io.Fonts, &pixels, &width, &height, null);
// upload texture to graphics system
GLint last_texture;
glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
glGenTextures(1, &font_texture_);
glBindTexture(GL_TEXTURE_2D, font_texture_);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
// store our identifier
ImFontAtlas_SetTexID(io.Fonts, cast(void*)font_texture_);
// restore state
glBindTexture(GL_TEXTURE_2D, last_texture);
}
void createDeviceObjects() {
// backup GL state
GLint last_texture, last_array_buffer, last_vertex_array;
if (last_texture != 0) glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
if (last_array_buffer != 0) glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
if (last_vertex_array != 0) glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
const GLchar *vertex_shader = q{
#version 330
uniform mat4 ProjMtx;
in vec2 Position;
in vec2 UV;
in vec4 Color;
out vec2 Frag_UV;
out vec4 Frag_Color;
void main() {
Frag_UV = UV;
Frag_Color = Color;
gl_Position = ProjMtx * vec4(Position.xy,0,1);
}
};
const GLchar* fragment_shader = q{
#version 330
uniform sampler2D Texture;
in vec2 Frag_UV;
in vec4 Frag_Color;
out vec4 Out_Color;
void main() {
Out_Color = Frag_Color * texture( Texture, Frag_UV.st);
}
};
shander_handle_ = glCreateProgram();
vs_handle_ = glCreateShader(GL_VERTEX_SHADER);
fs_handle_ = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(vs_handle_, 1, &vertex_shader, null);
glShaderSource(fs_handle_, 1, &fragment_shader, null);
glCompileShader(vs_handle_);
glCompileShader(fs_handle_);
glAttachShader(shander_handle_, vs_handle_);
glAttachShader(shander_handle_, fs_handle_);
glLinkProgram(shander_handle_);
shader_attrib_loc_tex_ = glGetUniformLocation(shander_handle_, "Texture");
shader_attrib_loc_projmtx_ = glGetUniformLocation(shander_handle_, "ProjMtx");
shader_attrib_loc_pos_ = glGetAttribLocation(shander_handle_, "Position");
shader_attrib_loc_uv_ = glGetAttribLocation(shander_handle_, "UV");
shader_attrib_loc_color_ = glGetAttribLocation(shander_handle_, "Color");
glGenBuffers(1, &vbo_);
glGenBuffers(1, &ebo_);
glGenVertexArrays(1, &vao_);
glBindVertexArray(vao_);
glBindBuffer(GL_ARRAY_BUFFER, vbo_);
glEnableVertexAttribArray(shader_attrib_loc_pos_);
glEnableVertexAttribArray(shader_attrib_loc_uv_);
glEnableVertexAttribArray(shader_attrib_loc_color_);
glVertexAttribPointer(shader_attrib_loc_pos_, 2, GL_FLOAT, GL_FALSE, ImDrawVert.sizeof, cast(void*)ImDrawVert.pos.offsetof);
glVertexAttribPointer(shader_attrib_loc_uv_, 2, GL_FLOAT, GL_FALSE, ImDrawVert.sizeof, cast(void*)ImDrawVert.uv.offsetof);
glVertexAttribPointer(shader_attrib_loc_color_, 4, GL_UNSIGNED_BYTE, GL_TRUE, ImDrawVert.sizeof, cast(void*)ImDrawVert.col.offsetof);
createFontTexture();
// restore modified GL state
glBindTexture(GL_TEXTURE_2D, last_texture);
glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
glBindVertexArray(last_vertex_array);
}
struct GLState {
GLenum last_active_texture;
GLint last_program;
GLint last_texture;
GLint last_array_buffer;
GLint last_element_array_buffer;
GLint last_vertex_array;
GLint[4] last_viewport;
GLint[4] last_scissor_box;
GLenum last_blend_src_rgb;
GLenum last_blend_dst_rgb;
GLenum last_blend_src_alpha;
GLenum last_blend_dst_alpha;
GLenum last_blend_equation_rgb;
GLenum last_blend_equation_alpha;
GLboolean last_enable_blend;
GLboolean last_enable_cull_face;
GLboolean last_enable_depth_test;
GLboolean last_enable_scissor_test;
}
nothrow @nogc
GLState backupGLState() {
GLState gl_state;
// backup GL state
with (gl_state) {
glGetIntegerv(GL_ACTIVE_TEXTURE, cast(GLint*)&last_active_texture);
glActiveTexture(GL_TEXTURE0);
glGetIntegerv(GL_CURRENT_PROGRAM, &last_program);
glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
glGetIntegerv(GL_ELEMENT_ARRAY_BUFFER_BINDING, &last_element_array_buffer);
glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
glGetIntegerv(GL_VIEWPORT, last_viewport.ptr);
glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box.ptr);
glGetIntegerv(GL_BLEND_SRC_RGB, cast(GLint*)&last_blend_src_rgb);
glGetIntegerv(GL_BLEND_DST_RGB, cast(GLint*)&last_blend_dst_rgb);
glGetIntegerv(GL_BLEND_SRC_ALPHA, cast(GLint*)&last_blend_src_alpha);
glGetIntegerv(GL_BLEND_DST_ALPHA, cast(GLint*)&last_blend_dst_alpha);
glGetIntegerv(GL_BLEND_EQUATION_RGB, cast(GLint*)&last_blend_equation_rgb);
glGetIntegerv(GL_BLEND_EQUATION_ALPHA, cast(GLint*)&last_blend_equation_alpha);
last_enable_blend = glIsEnabled(GL_BLEND);
last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
}
return gl_state;
}
nothrow @nogc
void restoreGLState(GLState state) {
// restore modified GL state
with (state) {
glUseProgram(last_program);
glBindTexture(GL_TEXTURE_2D, last_texture);
glActiveTexture(last_active_texture);
glBindVertexArray(last_vertex_array);
glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, last_element_array_buffer);
glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha);
glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb, last_blend_src_alpha, last_blend_dst_alpha);
if (last_enable_blend) glEnable(GL_BLEND); else glDisable(GL_BLEND);
if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE);
if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST);
if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST);
glViewport(last_viewport[0], last_viewport[1], cast(GLsizei)last_viewport[2], cast(GLsizei)last_viewport[3]);
glScissor(last_scissor_box[0], last_scissor_box[1], cast(GLsizei)last_scissor_box[2], cast(GLsizei)last_scissor_box[3]);
}
}
extern(C) nothrow
void renderDrawLists(ImDrawData* draw_data) {
// avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
auto io = igGetIO();
int fb_width = cast(int)(io.DisplaySize.x * io.DisplayFramebufferScale.x);
int fb_height = cast(int)(io.DisplaySize.y * io.DisplayFramebufferScale.y);
if (fb_width == 0 || fb_height == 0) { return; }
draw_data.ScaleClipRects(io.DisplayFramebufferScale);
// backup GL state
GLState last_state = backupGLState();
// Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled
glEnable(GL_BLEND);
glBlendEquation(GL_FUNC_ADD);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glDisable(GL_CULL_FACE);
glDisable(GL_DEPTH_TEST);
glEnable(GL_SCISSOR_TEST);
// Setup viewport, orthographic projection matrix
glViewport(0, 0, cast(GLsizei)fb_width, cast(GLsizei)fb_height);
const float[4][4] ortho_projection = [
[ 2.0f/io.DisplaySize.x, 0.0f, 0.0f, 0.0f ],
[ 0.0f, 2.0f/-io.DisplaySize.y, 0.0f, 0.0f ],
[ 0.0f, 0.0f, -1.0f, 0.0f ],
[-1.0f, 1.0f, 0.0f, 1.0f ],
];
glUseProgram(shander_handle_);
glUniform1i(shader_attrib_loc_tex_, 0);
glUniformMatrix4fv(shader_attrib_loc_projmtx_, 1, GL_FALSE, &ortho_projection[0][0]);
glBindVertexArray(vao_);
foreach (int n; 0 .. draw_data.CmdListsCount) {
ImDrawList* cmd_list = draw_data.CmdLists[n];
ImDrawIdx* idx_buffer_offset;
auto countVertices = ImDrawList_GetVertexBufferSize(cmd_list);
auto countIndices = ImDrawList_GetIndexBufferSize(cmd_list);
glBindBuffer(GL_ARRAY_BUFFER, vbo_);
glBufferData(GL_ARRAY_BUFFER, countVertices * ImDrawVert.sizeof, cast(GLvoid*)ImDrawList_GetVertexPtr(cmd_list,0), GL_STREAM_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo_);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, countIndices * ImDrawIdx.sizeof, cast(GLvoid*)ImDrawList_GetIndexPtr(cmd_list,0), GL_STREAM_DRAW);
auto cmdCnt = ImDrawList_GetCmdSize(cmd_list);
foreach(int cmd_i; 0 .. cmdCnt) {
auto pcmd = ImDrawList_GetCmdPtr(cmd_list, cmd_i);
if (pcmd.UserCallback) {
pcmd.UserCallback(cmd_list, pcmd);
} else {
glBindTexture(GL_TEXTURE_2D, cast(GLuint)pcmd.TextureId);
glScissor(cast(int)pcmd.ClipRect.x, cast(int)(fb_height - pcmd.ClipRect.w), cast(int)(pcmd.ClipRect.z - pcmd.ClipRect.x), cast(int)(pcmd.ClipRect.w - pcmd.ClipRect.y));
glDrawElements(GL_TRIANGLES, cast(GLsizei)pcmd.ElemCount, ImDrawIdx.sizeof == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer_offset);
}
idx_buffer_offset += pcmd.ElemCount;
}
}
// restore old state
restoreGLState(last_state);
}
extern(C) nothrow
const(char)* getClipboardText(void* user_data) {
return SDL_GetClipboardText();
}
extern(C) nothrow
void setClipboardText(void* user_data, const (char)* text) {
SDL_SetClipboardText(text);
}
void newFrame(ref Window win) {
auto io = igGetIO();
int win_w, win_h;
win.windowSize(win_w, win_h);
int fbo_w, fbo_h;
win.framebufferSize(fbo_w, fbo_h);
io.DisplaySize = ImVec2(win_w, win_h);
io.DisplayFramebufferScale = ImVec2(cast(float)fbo_w / win_w, cast(float)fbo_h / win_h);
int m_x, m_y;
win.mousePos(m_x, m_y);
io.MousePos = ImVec2(cast(float)m_x, cast(float)m_y);
io.MouseDown[0] = mouse_buttons_pressed[0] || (SDL_GetMouseState(null, null) & SDL_BUTTON_LEFT) != 0;
mouse_buttons_pressed[0] = false;
io.MouseDown[1] = mouse_buttons_pressed[0] || (SDL_GetMouseState(null, null) & SDL_BUTTON_MIDDLE) != 0;
mouse_buttons_pressed[1] = false;
io.MouseDown[2] = mouse_buttons_pressed[2] || (SDL_GetMouseState(null, null) & SDL_BUTTON_RIGHT) != 0;
mouse_buttons_pressed[2] = false;
io.MouseWheel = scroll_wheel;
scroll_wheel = 0.0f;
igNewFrame();
}
void endFrame() {
igRender();
}
void handleEvent(ref SDL_Event ev) {
auto io = igGetIO();
switch (ev.type) with (SDL_EventType) {
case SDL_TEXTINPUT:
ImGuiIO_AddInputCharacter(cast(ushort)ev.text.text[0]);
break;
case SDL_KEYDOWN, SDL_KEYUP:
auto mods = ev.key.keysym.mod;
io.KeyCtrl = (mods & KMOD_CTRL) != 0;
io.KeyShift = (mods & KMOD_SHIFT) != 0;
io.KeyAlt = (mods & KMOD_ALT) != 0;
break;
case SDL_MOUSEBUTTONDOWN, SDL_MOUSEBUTTONUP:
auto btn = ev.button.button;
if (btn < 4) {
mouse_buttons_pressed[btn - 1] = (ev.type == SDL_MOUSEBUTTONDOWN);
}
break;
case SDL_MOUSEWHEEL:
scroll_wheel += ev.wheel.y;
break;
default:
break;
}
}
}