1
0
mirror of https://github.com/ocornut/imgui.git synced 2024-11-28 09:30:56 +01:00
imgui/examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp
Emmanuel Benoît 77a310736d Horizontal mouse wheel support
This patch adds support for the horizontal mouse wheel in ImGui. It
affects windows that can be scrolled, as long as the Ctrl key is not
being pressed.

The scrolling speed has been set empirically so that it matches the
scrolling speed on the Firefox browser when the horizontal wheel is
used.

Internally, it adds a MouseHorizWheel to ImGuiIO, which is then used in
NewFrame to scroll the current window.

The SDL/GL2, SDL/GL3, GLFW/GL2 and GLFW/GL3 examples has been modified
to use it.
2017-11-27 20:59:05 +01:00

414 lines
18 KiB
C++

// ImGui SDL2 binding with OpenGL3
// In this binding, ImTextureID is used to store an OpenGL 'GLuint' texture identifier. Read the FAQ about ImTextureID in imgui.cpp.
// (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
// (GL3W is a helper library to access OpenGL functions since there is no standard header to access modern OpenGL functions easily. Alternatives are GLEW, Glad, etc.)
// You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
// If you use this binding you'll need to call 4 functions: ImGui_ImplXXXX_Init(), ImGui_ImplXXXX_NewFrame(), ImGui::Render() and ImGui_ImplXXXX_Shutdown().
// If you are new to ImGui, see examples/README.txt and documentation at the top of imgui.cpp.
// https://github.com/ocornut/imgui
#include "imgui.h"
#include "imgui_impl_sdl_gl3.h"
// SDL,GL3W
#include <SDL.h>
#include <SDL_syswm.h>
#include <GL/gl3w.h> // This example is using gl3w to access OpenGL functions (because it is small). You may use glew/glad/glLoadGen/etc. whatever already works for you.
// Data
static double g_Time = 0.0f;
static bool g_MousePressed[3] = { false, false, false };
static float g_MouseHorizWheel = 0.0f;
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 unsigned int g_VboHandle = 0, g_VaoHandle = 0, g_ElementsHandle = 0;
// This is the main rendering function that you have to implement and provide to ImGui (via setting up 'RenderDrawListsFn' in the ImGuiIO structure)
// Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly, in order to be able to run within any OpenGL engine that doesn't do so.
// 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)
void ImGui_ImplSdlGL3_RenderDrawLists(ImDrawData* draw_data)
{
// Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
ImGuiIO& io = ImGui::GetIO();
int fb_width = (int)(io.DisplaySize.x * io.DisplayFramebufferScale.x);
int fb_height = (int)(io.DisplaySize.y * io.DisplayFramebufferScale.y);
if (fb_width == 0 || fb_height == 0)
return;
draw_data->ScaleClipRects(io.DisplayFramebufferScale);
// Backup GL state
GLenum last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint*)&last_active_texture);
glActiveTexture(GL_TEXTURE0);
GLint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, &last_program);
GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
GLint last_sampler; glGetIntegerv(GL_SAMPLER_BINDING, &last_sampler);
GLint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
GLint last_element_array_buffer; glGetIntegerv(GL_ELEMENT_ARRAY_BUFFER_BINDING, &last_element_array_buffer);
GLint last_vertex_array; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box);
GLenum last_blend_src_rgb; glGetIntegerv(GL_BLEND_SRC_RGB, (GLint*)&last_blend_src_rgb);
GLenum last_blend_dst_rgb; glGetIntegerv(GL_BLEND_DST_RGB, (GLint*)&last_blend_dst_rgb);
GLenum last_blend_src_alpha; glGetIntegerv(GL_BLEND_SRC_ALPHA, (GLint*)&last_blend_src_alpha);
GLenum last_blend_dst_alpha; glGetIntegerv(GL_BLEND_DST_ALPHA, (GLint*)&last_blend_dst_alpha);
GLenum last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, (GLint*)&last_blend_equation_rgb);
GLenum last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, (GLint*)&last_blend_equation_alpha);
GLboolean last_enable_blend = glIsEnabled(GL_BLEND);
GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE);
GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST);
GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST);
// Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
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);
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
// Setup viewport, orthographic projection matrix
glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height);
const float ortho_projection[4][4] =
{
{ 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(g_ShaderHandle);
glUniform1i(g_AttribLocationTex, 0);
glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
glBindVertexArray(g_VaoHandle);
glBindSampler(0, 0); // Rely on combined texture/sampler state.
for (int n = 0; n < draw_data->CmdListsCount; n++)
{
const ImDrawList* cmd_list = draw_data->CmdLists[n];
const ImDrawIdx* idx_buffer_offset = 0;
glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)cmd_list->VtxBuffer.Size * sizeof(ImDrawVert), (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, (GLsizeiptr)cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx), (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW);
for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
{
const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
if (pcmd->UserCallback)
{
pcmd->UserCallback(cmd_list, pcmd);
}
else
{
glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
glScissor((int)pcmd->ClipRect.x, (int)(fb_height - pcmd->ClipRect.w), (int)(pcmd->ClipRect.z - pcmd->ClipRect.x), (int)(pcmd->ClipRect.w - pcmd->ClipRect.y));
glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer_offset);
}
idx_buffer_offset += pcmd->ElemCount;
}
}
// Restore modified GL state
glUseProgram(last_program);
glBindTexture(GL_TEXTURE_2D, last_texture);
glBindSampler(0, last_sampler);
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);
glPolygonMode(GL_FRONT_AND_BACK, last_polygon_mode[0]);
glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
}
static const char* ImGui_ImplSdlGL3_GetClipboardText(void*)
{
return SDL_GetClipboardText();
}
static void ImGui_ImplSdlGL3_SetClipboardText(void*, const char* text)
{
SDL_SetClipboardText(text);
}
// You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
// - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
// - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
// Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
bool ImGui_ImplSdlGL3_ProcessEvent(SDL_Event* event)
{
ImGuiIO& io = ImGui::GetIO();
switch (event->type)
{
case SDL_MOUSEWHEEL:
{
if (event->wheel.x > 0)
g_MouseHorizWheel = 1;
if (event->wheel.x < 0)
g_MouseHorizWheel = -1;
if (event->wheel.y > 0)
g_MouseWheel = 1;
if (event->wheel.y < 0)
g_MouseWheel = -1;
return true;
}
case SDL_MOUSEBUTTONDOWN:
{
if (event->button.button == SDL_BUTTON_LEFT) g_MousePressed[0] = true;
if (event->button.button == SDL_BUTTON_RIGHT) g_MousePressed[1] = true;
if (event->button.button == SDL_BUTTON_MIDDLE) g_MousePressed[2] = true;
return true;
}
case SDL_TEXTINPUT:
{
io.AddInputCharactersUTF8(event->text.text);
return true;
}
case SDL_KEYDOWN:
case SDL_KEYUP:
{
int key = event->key.keysym.sym & ~SDLK_SCANCODE_MASK;
io.KeysDown[key] = (event->type == SDL_KEYDOWN);
io.KeyShift = ((SDL_GetModState() & KMOD_SHIFT) != 0);
io.KeyCtrl = ((SDL_GetModState() & KMOD_CTRL) != 0);
io.KeyAlt = ((SDL_GetModState() & KMOD_ALT) != 0);
io.KeySuper = ((SDL_GetModState() & KMOD_GUI) != 0);
return true;
}
}
return false;
}
void ImGui_ImplSdlGL3_CreateFontsTexture()
{
// Build texture atlas
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.
// Upload texture to graphics system
GLint last_texture;
glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
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);
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
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;
// Restore state
glBindTexture(GL_TEXTURE_2D, last_texture);
}
bool ImGui_ImplSdlGL3_CreateDeviceObjects()
{
// Backup GL state
GLint last_texture, last_array_buffer, last_vertex_array;
glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
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);
glGenBuffers(1, &g_ElementsHandle);
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
ImGui_ImplSdlGL3_CreateFontsTexture();
// Restore modified GL state
glBindTexture(GL_TEXTURE_2D, last_texture);
glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer);
glBindVertexArray(last_vertex_array);
return true;
}
void ImGui_ImplSdlGL3_InvalidateDeviceObjects()
{
if (g_VaoHandle) glDeleteVertexArrays(1, &g_VaoHandle);
if (g_VboHandle) glDeleteBuffers(1, &g_VboHandle);
if (g_ElementsHandle) glDeleteBuffers(1, &g_ElementsHandle);
g_VaoHandle = g_VboHandle = g_ElementsHandle = 0;
if (g_ShaderHandle && g_VertHandle) glDetachShader(g_ShaderHandle, g_VertHandle);
if (g_VertHandle) glDeleteShader(g_VertHandle);
g_VertHandle = 0;
if (g_ShaderHandle && g_FragHandle) glDetachShader(g_ShaderHandle, g_FragHandle);
if (g_FragHandle) glDeleteShader(g_FragHandle);
g_FragHandle = 0;
if (g_ShaderHandle) glDeleteProgram(g_ShaderHandle);
g_ShaderHandle = 0;
if (g_FontTexture)
{
glDeleteTextures(1, &g_FontTexture);
ImGui::GetIO().Fonts->TexID = 0;
g_FontTexture = 0;
}
}
bool ImGui_ImplSdlGL3_Init(SDL_Window* window)
{
ImGuiIO& io = ImGui::GetIO();
io.KeyMap[ImGuiKey_Tab] = SDLK_TAB; // Keyboard mapping. ImGui will use those indices to peek into the io.KeyDown[] array.
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] = SDLK_DELETE;
io.KeyMap[ImGuiKey_Backspace] = SDLK_BACKSPACE;
io.KeyMap[ImGuiKey_Enter] = SDLK_RETURN;
io.KeyMap[ImGuiKey_Escape] = SDLK_ESCAPE;
io.KeyMap[ImGuiKey_A] = SDLK_a;
io.KeyMap[ImGuiKey_C] = SDLK_c;
io.KeyMap[ImGuiKey_V] = SDLK_v;
io.KeyMap[ImGuiKey_X] = SDLK_x;
io.KeyMap[ImGuiKey_Y] = SDLK_y;
io.KeyMap[ImGuiKey_Z] = SDLK_z;
io.RenderDrawListsFn = ImGui_ImplSdlGL3_RenderDrawLists; // Alternatively you can set this to NULL and call ImGui::GetDrawData() after ImGui::Render() to get the same ImDrawData pointer.
io.SetClipboardTextFn = ImGui_ImplSdlGL3_SetClipboardText;
io.GetClipboardTextFn = ImGui_ImplSdlGL3_GetClipboardText;
io.ClipboardUserData = NULL;
#ifdef _WIN32
SDL_SysWMinfo wmInfo;
SDL_VERSION(&wmInfo.version);
SDL_GetWindowWMInfo(window, &wmInfo);
io.ImeWindowHandle = wmInfo.info.win.window;
#else
(void)window;
#endif
return true;
}
void ImGui_ImplSdlGL3_Shutdown()
{
ImGui_ImplSdlGL3_InvalidateDeviceObjects();
ImGui::Shutdown();
}
void ImGui_ImplSdlGL3_NewFrame(SDL_Window* window)
{
if (!g_FontTexture)
ImGui_ImplSdlGL3_CreateDeviceObjects();
ImGuiIO& io = ImGui::GetIO();
// Setup display size (every frame to accommodate for window resizing)
int w, h;
int display_w, display_h;
SDL_GetWindowSize(window, &w, &h);
SDL_GL_GetDrawableSize(window, &display_w, &display_h);
io.DisplaySize = ImVec2((float)w, (float)h);
io.DisplayFramebufferScale = ImVec2(w > 0 ? ((float)display_w / w) : 0, h > 0 ? ((float)display_h / h) : 0);
// Setup time step
Uint32 time = SDL_GetTicks();
double current_time = time / 1000.0;
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 SDL_PollEvent())
int mx, my;
Uint32 mouseMask = SDL_GetMouseState(&mx, &my);
if (SDL_GetWindowFlags(window) & SDL_WINDOW_MOUSE_FOCUS)
io.MousePos = ImVec2((float)mx, (float)my); // Mouse position, in pixels (set to -1,-1 if no mouse / on another screen, etc.)
else
io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
io.MouseDown[0] = g_MousePressed[0] || (mouseMask & SDL_BUTTON(SDL_BUTTON_LEFT)) != 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.
io.MouseDown[1] = g_MousePressed[1] || (mouseMask & SDL_BUTTON(SDL_BUTTON_RIGHT)) != 0;
io.MouseDown[2] = g_MousePressed[2] || (mouseMask & SDL_BUTTON(SDL_BUTTON_MIDDLE)) != 0;
g_MousePressed[0] = g_MousePressed[1] = g_MousePressed[2] = false;
io.MouseHorizWheel = g_MouseHorizWheel;
io.MouseWheel = g_MouseWheel;
g_MouseHorizWheel = g_MouseWheel = 0.0f;
// Hide OS mouse cursor if ImGui is drawing it
SDL_ShowCursor(io.MouseDrawCursor ? 0 : 1);
// Start the frame. This call will update the io.WantCaptureMouse, io.WantCaptureKeyboard flag that you can use to dispatch inputs (or not) to your application.
ImGui::NewFrame();
}