mirror of
https://github.com/Drezil/imgui.git
synced 2024-11-15 09:27:00 +00:00
358 lines
13 KiB
C++
358 lines
13 KiB
C++
// ImGui GLFW binding with OpenGL3 + shaders
|
|
// https://github.com/ocornut/imgui
|
|
|
|
#include <imgui.h>
|
|
#include "imgui_impl_glfw_gl3.h"
|
|
|
|
// GL3W/GLFW
|
|
#include <GL/gl3w.h>
|
|
#include <GLFW/glfw3.h>
|
|
#ifdef _MSC_VER
|
|
#undef APIENTRY
|
|
#define GLFW_EXPOSE_NATIVE_WIN32
|
|
#define GLFW_EXPOSE_NATIVE_WGL
|
|
#include <GLFW/glfw3native.h>
|
|
#endif
|
|
|
|
// Data
|
|
static GLFWwindow* g_Window = NULL;
|
|
static double g_Time = 0.0f;
|
|
static bool g_MousePressed[3] = { false, false, false };
|
|
static float g_MouseWheel = 0.0f;
|
|
static GLuint g_FontTexture = 0;
|
|
static int g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0;
|
|
static int g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0;
|
|
static int g_AttribLocationPosition = 0, g_AttribLocationUV = 0, g_AttribLocationColor = 0;
|
|
static size_t g_VboSize = 0;
|
|
static unsigned int g_VboHandle = 0, g_VaoHandle = 0;
|
|
|
|
// This is the main rendering function that you have to implement and provide to ImGui (via setting up 'RenderDrawListsFn' in the ImGuiIO structure)
|
|
// If text or lines are blurry when integrating ImGui in your engine:
|
|
// - in your Render function, try translating your projection matrix by (0.5f,0.5f) or (0.375f,0.375f)
|
|
static void ImGui_ImplGlfwGL3_RenderDrawLists(ImDrawList** const cmd_lists, int cmd_lists_count)
|
|
{
|
|
if (cmd_lists_count == 0)
|
|
return;
|
|
|
|
// 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);
|
|
glActiveTexture(GL_TEXTURE0);
|
|
|
|
// Setup orthographic projection matrix
|
|
const float width = ImGui::GetIO().DisplaySize.x;
|
|
const float height = ImGui::GetIO().DisplaySize.y;
|
|
const float ortho_projection[4][4] =
|
|
{
|
|
{ 2.0f/width, 0.0f, 0.0f, 0.0f },
|
|
{ 0.0f, 2.0f/-height, 0.0f, 0.0f },
|
|
{ 0.0f, 0.0f, -1.0f, 0.0f },
|
|
{ -1.0f, 1.0f, 0.0f, 1.0f },
|
|
};
|
|
glUseProgram(g_ShaderHandle);
|
|
glUniform1i(g_AttribLocationTex, 0);
|
|
glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
|
|
|
|
// Grow our buffer according to what we need
|
|
size_t total_vtx_count = 0;
|
|
for (int n = 0; n < cmd_lists_count; n++)
|
|
total_vtx_count += cmd_lists[n]->vtx_buffer.size();
|
|
glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
|
|
size_t needed_vtx_size = total_vtx_count * sizeof(ImDrawVert);
|
|
if (g_VboSize < needed_vtx_size)
|
|
{
|
|
g_VboSize = needed_vtx_size + 5000 * sizeof(ImDrawVert); // Grow buffer
|
|
glBufferData(GL_ARRAY_BUFFER, g_VboSize, NULL, GL_STREAM_DRAW);
|
|
}
|
|
|
|
// Copy and convert all vertices into a single contiguous buffer
|
|
unsigned char* buffer_data = (unsigned char*)glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
|
|
if (!buffer_data)
|
|
return;
|
|
for (int n = 0; n < cmd_lists_count; n++)
|
|
{
|
|
const ImDrawList* cmd_list = cmd_lists[n];
|
|
memcpy(buffer_data, &cmd_list->vtx_buffer[0], cmd_list->vtx_buffer.size() * sizeof(ImDrawVert));
|
|
buffer_data += cmd_list->vtx_buffer.size() * sizeof(ImDrawVert);
|
|
}
|
|
glUnmapBuffer(GL_ARRAY_BUFFER);
|
|
glBindBuffer(GL_ARRAY_BUFFER, 0);
|
|
glBindVertexArray(g_VaoHandle);
|
|
|
|
int cmd_offset = 0;
|
|
for (int n = 0; n < cmd_lists_count; n++)
|
|
{
|
|
const ImDrawList* cmd_list = cmd_lists[n];
|
|
int vtx_offset = cmd_offset;
|
|
const ImDrawCmd* pcmd_end = cmd_list->commands.end();
|
|
for (const ImDrawCmd* pcmd = cmd_list->commands.begin(); pcmd != pcmd_end; pcmd++)
|
|
{
|
|
if (pcmd->user_callback)
|
|
{
|
|
pcmd->user_callback(cmd_list, pcmd);
|
|
}
|
|
else
|
|
{
|
|
glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->texture_id);
|
|
glScissor((int)pcmd->clip_rect.x, (int)(height - pcmd->clip_rect.w), (int)(pcmd->clip_rect.z - pcmd->clip_rect.x), (int)(pcmd->clip_rect.w - pcmd->clip_rect.y));
|
|
glDrawArrays(GL_TRIANGLES, vtx_offset, pcmd->vtx_count);
|
|
}
|
|
vtx_offset += pcmd->vtx_count;
|
|
}
|
|
cmd_offset = vtx_offset;
|
|
}
|
|
|
|
// Restore modified state
|
|
glBindVertexArray(0);
|
|
glUseProgram(0);
|
|
glDisable(GL_SCISSOR_TEST);
|
|
glBindTexture(GL_TEXTURE_2D, 0);
|
|
}
|
|
|
|
static const char* ImGui_ImplGlfwGL3_GetClipboardText()
|
|
{
|
|
return glfwGetClipboardString(g_Window);
|
|
}
|
|
|
|
static void ImGui_ImplGlfwGL3_SetClipboardText(const char* text)
|
|
{
|
|
glfwSetClipboardString(g_Window, text);
|
|
}
|
|
|
|
void ImGui_ImplGlfwGL3_MouseButtonCallback(GLFWwindow*, int button, int action, int /*mods*/)
|
|
{
|
|
if (action == GLFW_PRESS && button >= 0 && button < 3)
|
|
g_MousePressed[button] = true;
|
|
}
|
|
|
|
void ImGui_ImplGlfwGL3_ScrollCallback(GLFWwindow*, double /*xoffset*/, double yoffset)
|
|
{
|
|
g_MouseWheel += (float)yoffset; // Use fractional mouse wheel, 1.0 unit 5 lines.
|
|
}
|
|
|
|
void ImGui_ImplGlfwGL3_KeyCallback(GLFWwindow*, int key, int, int action, int mods)
|
|
{
|
|
ImGuiIO& io = ImGui::GetIO();
|
|
if (action == GLFW_PRESS)
|
|
io.KeysDown[key] = true;
|
|
if (action == GLFW_RELEASE)
|
|
io.KeysDown[key] = false;
|
|
io.KeyCtrl = (mods & GLFW_MOD_CONTROL) != 0;
|
|
io.KeyShift = (mods & GLFW_MOD_SHIFT) != 0;
|
|
io.KeyAlt = (mods & GLFW_MOD_ALT) != 0;
|
|
}
|
|
|
|
void ImGui_ImplGlfwGL3_CharCallback(GLFWwindow*, unsigned int c)
|
|
{
|
|
ImGuiIO& io = ImGui::GetIO();
|
|
if (c > 0 && c < 0x10000)
|
|
io.AddInputCharacter((unsigned short)c);
|
|
}
|
|
|
|
void ImGui_ImplGlfwGL3_CreateFontsTexture()
|
|
{
|
|
ImGuiIO& io = ImGui::GetIO();
|
|
|
|
unsigned char* pixels;
|
|
int width, height;
|
|
io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); // Load as RGBA 32-bits for OpenGL3 demo because it is more likely to be compatible with user's existing shader.
|
|
|
|
glGenTextures(1, &g_FontTexture);
|
|
glBindTexture(GL_TEXTURE_2D, g_FontTexture);
|
|
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
|
|
io.Fonts->TexID = (void *)(intptr_t)g_FontTexture;
|
|
}
|
|
|
|
bool ImGui_ImplGlfwGL3_CreateDeviceObjects()
|
|
{
|
|
const GLchar *vertex_shader =
|
|
"#version 330\n"
|
|
"uniform mat4 ProjMtx;\n"
|
|
"in vec2 Position;\n"
|
|
"in vec2 UV;\n"
|
|
"in vec4 Color;\n"
|
|
"out vec2 Frag_UV;\n"
|
|
"out vec4 Frag_Color;\n"
|
|
"void main()\n"
|
|
"{\n"
|
|
" Frag_UV = UV;\n"
|
|
" Frag_Color = Color;\n"
|
|
" gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
|
|
"}\n";
|
|
|
|
const GLchar* fragment_shader =
|
|
"#version 330\n"
|
|
"uniform sampler2D Texture;\n"
|
|
"in vec2 Frag_UV;\n"
|
|
"in vec4 Frag_Color;\n"
|
|
"out vec4 Out_Color;\n"
|
|
"void main()\n"
|
|
"{\n"
|
|
" Out_Color = Frag_Color * texture( Texture, Frag_UV.st);\n"
|
|
"}\n";
|
|
|
|
g_ShaderHandle = glCreateProgram();
|
|
g_VertHandle = glCreateShader(GL_VERTEX_SHADER);
|
|
g_FragHandle = glCreateShader(GL_FRAGMENT_SHADER);
|
|
glShaderSource(g_VertHandle, 1, &vertex_shader, 0);
|
|
glShaderSource(g_FragHandle, 1, &fragment_shader, 0);
|
|
glCompileShader(g_VertHandle);
|
|
glCompileShader(g_FragHandle);
|
|
glAttachShader(g_ShaderHandle, g_VertHandle);
|
|
glAttachShader(g_ShaderHandle, g_FragHandle);
|
|
glLinkProgram(g_ShaderHandle);
|
|
|
|
g_AttribLocationTex = glGetUniformLocation(g_ShaderHandle, "Texture");
|
|
g_AttribLocationProjMtx = glGetUniformLocation(g_ShaderHandle, "ProjMtx");
|
|
g_AttribLocationPosition = glGetAttribLocation(g_ShaderHandle, "Position");
|
|
g_AttribLocationUV = glGetAttribLocation(g_ShaderHandle, "UV");
|
|
g_AttribLocationColor = glGetAttribLocation(g_ShaderHandle, "Color");
|
|
|
|
glGenBuffers(1, &g_VboHandle);
|
|
|
|
glGenVertexArrays(1, &g_VaoHandle);
|
|
glBindVertexArray(g_VaoHandle);
|
|
glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
|
|
glEnableVertexAttribArray(g_AttribLocationPosition);
|
|
glEnableVertexAttribArray(g_AttribLocationUV);
|
|
glEnableVertexAttribArray(g_AttribLocationColor);
|
|
|
|
#define OFFSETOF(TYPE, ELEMENT) ((size_t)&(((TYPE *)0)->ELEMENT))
|
|
glVertexAttribPointer(g_AttribLocationPosition, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, pos));
|
|
glVertexAttribPointer(g_AttribLocationUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, uv));
|
|
glVertexAttribPointer(g_AttribLocationColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, col));
|
|
#undef OFFSETOF
|
|
glBindVertexArray(0);
|
|
glBindBuffer(GL_ARRAY_BUFFER, 0);
|
|
|
|
ImGui_ImplGlfwGL3_CreateFontsTexture();
|
|
|
|
return true;
|
|
}
|
|
|
|
bool ImGui_ImplGlfwGL3_Init(GLFWwindow* window, bool install_callbacks)
|
|
{
|
|
g_Window = window;
|
|
|
|
ImGuiIO& io = ImGui::GetIO();
|
|
io.KeyMap[ImGuiKey_Tab] = GLFW_KEY_TAB; // Keyboard mapping. ImGui will use those indices to peek into the io.KeyDown[] array.
|
|
io.KeyMap[ImGuiKey_LeftArrow] = GLFW_KEY_LEFT;
|
|
io.KeyMap[ImGuiKey_RightArrow] = GLFW_KEY_RIGHT;
|
|
io.KeyMap[ImGuiKey_UpArrow] = GLFW_KEY_UP;
|
|
io.KeyMap[ImGuiKey_DownArrow] = GLFW_KEY_DOWN;
|
|
io.KeyMap[ImGuiKey_Home] = GLFW_KEY_HOME;
|
|
io.KeyMap[ImGuiKey_End] = GLFW_KEY_END;
|
|
io.KeyMap[ImGuiKey_Delete] = GLFW_KEY_DELETE;
|
|
io.KeyMap[ImGuiKey_Backspace] = GLFW_KEY_BACKSPACE;
|
|
io.KeyMap[ImGuiKey_Enter] = GLFW_KEY_ENTER;
|
|
io.KeyMap[ImGuiKey_Escape] = GLFW_KEY_ESCAPE;
|
|
io.KeyMap[ImGuiKey_A] = GLFW_KEY_A;
|
|
io.KeyMap[ImGuiKey_C] = GLFW_KEY_C;
|
|
io.KeyMap[ImGuiKey_V] = GLFW_KEY_V;
|
|
io.KeyMap[ImGuiKey_X] = GLFW_KEY_X;
|
|
io.KeyMap[ImGuiKey_Y] = GLFW_KEY_Y;
|
|
io.KeyMap[ImGuiKey_Z] = GLFW_KEY_Z;
|
|
|
|
io.RenderDrawListsFn = ImGui_ImplGlfwGL3_RenderDrawLists;
|
|
io.SetClipboardTextFn = ImGui_ImplGlfwGL3_SetClipboardText;
|
|
io.GetClipboardTextFn = ImGui_ImplGlfwGL3_GetClipboardText;
|
|
#ifdef _MSC_VER
|
|
io.ImeWindowHandle = glfwGetWin32Window(g_Window);
|
|
#endif
|
|
|
|
if (install_callbacks)
|
|
{
|
|
glfwSetMouseButtonCallback(window, ImGui_ImplGlfwGL3_MouseButtonCallback);
|
|
glfwSetScrollCallback(window, ImGui_ImplGlfwGL3_ScrollCallback);
|
|
glfwSetKeyCallback(window, ImGui_ImplGlfwGL3_KeyCallback);
|
|
glfwSetCharCallback(window, ImGui_ImplGlfwGL3_CharCallback);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
void ImGui_ImplGlfwGL3_Shutdown()
|
|
{
|
|
if (g_VaoHandle) glDeleteVertexArrays(1, &g_VaoHandle);
|
|
if (g_VboHandle) glDeleteBuffers(1, &g_VboHandle);
|
|
g_VaoHandle = 0;
|
|
g_VboHandle = 0;
|
|
|
|
glDetachShader(g_ShaderHandle, g_VertHandle);
|
|
glDeleteShader(g_VertHandle);
|
|
g_VertHandle = 0;
|
|
|
|
glDetachShader(g_ShaderHandle, g_FragHandle);
|
|
glDeleteShader(g_FragHandle);
|
|
g_FragHandle = 0;
|
|
|
|
glDeleteProgram(g_ShaderHandle);
|
|
g_ShaderHandle = 0;
|
|
|
|
if (g_FontTexture)
|
|
{
|
|
glDeleteTextures(1, &g_FontTexture);
|
|
ImGui::GetIO().Fonts->TexID = 0;
|
|
g_FontTexture = 0;
|
|
}
|
|
ImGui::Shutdown();
|
|
}
|
|
|
|
void ImGui_ImplGlfwGL3_NewFrame()
|
|
{
|
|
if (!g_FontTexture)
|
|
ImGui_ImplGlfwGL3_CreateDeviceObjects();
|
|
|
|
ImGuiIO& io = ImGui::GetIO();
|
|
|
|
// Setup display size (every frame to accommodate for window resizing)
|
|
int w, h;
|
|
int display_w, display_h;
|
|
glfwGetWindowSize(g_Window, &w, &h);
|
|
glfwGetFramebufferSize(g_Window, &display_w, &display_h);
|
|
io.DisplaySize = ImVec2((float)display_w, (float)display_h);
|
|
|
|
// Setup time step
|
|
double current_time = glfwGetTime();
|
|
io.DeltaTime = g_Time > 0.0 ? (float)(current_time - g_Time) : (float)(1.0f/60.0f);
|
|
g_Time = current_time;
|
|
|
|
// Setup inputs
|
|
// (we already got mouse wheel, keyboard keys & characters from glfw callbacks polled in glfwPollEvents())
|
|
if (glfwGetWindowAttrib(g_Window, GLFW_FOCUSED))
|
|
{
|
|
double mouse_x, mouse_y;
|
|
glfwGetCursorPos(g_Window, &mouse_x, &mouse_y);
|
|
mouse_x *= (float)display_w / w; // Convert mouse coordinates to pixels
|
|
mouse_y *= (float)display_h / h;
|
|
io.MousePos = ImVec2((float)mouse_x, (float)mouse_y); // Mouse position, in pixels (set to -1,-1 if no mouse / on another screen, etc.)
|
|
}
|
|
else
|
|
{
|
|
io.MousePos = ImVec2(-1,-1);
|
|
}
|
|
|
|
for (int i = 0; i < 3; i++)
|
|
{
|
|
io.MouseDown[i] = g_MousePressed[i] || glfwGetMouseButton(g_Window, i) != 0; // If a mouse press event came, always pass it as "mouse held this frame", so we don't miss click-release events that are shorter than 1 frame.
|
|
g_MousePressed[i] = false;
|
|
}
|
|
|
|
io.MouseWheel = g_MouseWheel;
|
|
g_MouseWheel = 0.0f;
|
|
|
|
// Hide/show hardware mouse cursor
|
|
glfwSetInputMode(g_Window, GLFW_CURSOR, io.MouseDrawCursor ? GLFW_CURSOR_HIDDEN : GLFW_CURSOR_NORMAL);
|
|
|
|
// Start the frame
|
|
ImGui::NewFrame();
|
|
}
|