rev: 21c5e6d2f665d0e8b4ff917a51b664c895dab2ed tukan/src/tukan/imgui_impl_sdl_gl3.cpp -rw-r--r-- 18.2 KiB View raw Log this file
21c5e6d2f665 — Leonard Ritter * renamed project from Liminal to Tukan 2 years ago
                                                                                
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
// 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 "tukan/imgui_impl_sdl_gl3.h"

// SDL,GL3W
#include <SDL.h>
#include <SDL_syswm.h>
#include "glad.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_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.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.MouseWheel = g_MouseWheel;
    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();
}