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Diffstat (limited to '3rdparty/imgui/examples/imgui_impl_opengl2.cpp')
| -rw-r--r-- | 3rdparty/imgui/examples/imgui_impl_opengl2.cpp | 212 |
1 files changed, 212 insertions, 0 deletions
diff --git a/3rdparty/imgui/examples/imgui_impl_opengl2.cpp b/3rdparty/imgui/examples/imgui_impl_opengl2.cpp new file mode 100644 index 00000000..5acf12f1 --- /dev/null +++ b/3rdparty/imgui/examples/imgui_impl_opengl2.cpp @@ -0,0 +1,212 @@ +// dear imgui: Renderer for OpenGL2 (legacy OpenGL, fixed pipeline) +// This needs to be used along with a Platform Binding (e.g. GLFW, SDL, Win32, custom..) + +// Implemented features: +// [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID in imgui.cpp. + +// You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this. +// If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp. +// https://github.com/ocornut/imgui + +// **DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)** +// **Prefer using the code in imgui_impl_opengl3.cpp** +// This code is mostly provided as a reference to learn how ImGui integration works, because it is shorter to read. +// If your code is using GL3+ context or any semi modern OpenGL calls, using this is likely to make everything more +// complicated, will require your code to reset every single OpenGL attributes to their initial state, and might +// confuse your GPU driver. +// The GL2 code is unable to reset attributes or even call e.g. "glUseProgram(0)" because they don't exist in that API. + +// CHANGELOG +// (minor and older changes stripped away, please see git history for details) +// 2018-08-03: OpenGL: Disabling/restoring GL_LIGHTING and GL_COLOR_MATERIAL to increase compatibility with legacy OpenGL applications. +// 2018-06-08: Misc: Extracted imgui_impl_opengl2.cpp/.h away from the old combined GLFW/SDL+OpenGL2 examples. +// 2018-06-08: OpenGL: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle. +// 2018-02-16: Misc: Obsoleted the io.RenderDrawListsFn callback and exposed ImGui_ImplGlfwGL2_RenderDrawData() in the .h file so you can call it yourself. +// 2017-09-01: OpenGL: Save and restore current polygon mode. +// 2016-09-10: OpenGL: Uploading font texture as RGBA32 to increase compatibility with users shaders (not ideal). +// 2016-09-05: OpenGL: Fixed save and restore of current scissor rectangle. + +#include "imgui.h" +#include "imgui_impl_opengl2.h" +#if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier +#include <stddef.h> // intptr_t +#else +#include <stdint.h> // intptr_t +#endif + +// Include OpenGL header (without an OpenGL loader) requires a bit of fiddling +#if defined(_WIN32) && !defined(APIENTRY) +#define APIENTRY __stdcall // It is customary to use APIENTRY for OpenGL function pointer declarations on all platforms. Additionally, the Windows OpenGL header needs APIENTRY. +#endif +#if defined(_WIN32) && !defined(WINGDIAPI) +#define WINGDIAPI __declspec(dllimport) // Some Windows OpenGL headers need this +#endif +#if defined(__APPLE__) +#include <OpenGL/gl.h> +#else +#include <GL/gl.h> +#endif + +// OpenGL Data +static GLuint g_FontTexture = 0; + +// Functions +bool ImGui_ImplOpenGL2_Init() +{ + return true; +} + +void ImGui_ImplOpenGL2_Shutdown() +{ + ImGui_ImplOpenGL2_DestroyDeviceObjects(); +} + +void ImGui_ImplOpenGL2_NewFrame() +{ + if (!g_FontTexture) + ImGui_ImplOpenGL2_CreateDeviceObjects(); +} + +// OpenGL2 Render function. +// (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop) +// 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. +void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data) +{ + // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates) + ImGuiIO& io = ImGui::GetIO(); + int fb_width = (int)(draw_data->DisplaySize.x * io.DisplayFramebufferScale.x); + int fb_height = (int)(draw_data->DisplaySize.y * io.DisplayFramebufferScale.y); + if (fb_width == 0 || fb_height == 0) + return; + draw_data->ScaleClipRects(io.DisplayFramebufferScale); + + // We are using the OpenGL fixed pipeline to make the example code simpler to read! + // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers, polygon fill. + GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture); + 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); + glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT | GL_TRANSFORM_BIT); + glEnable(GL_BLEND); + glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); + glDisable(GL_CULL_FACE); + glDisable(GL_DEPTH_TEST); + glDisable(GL_LIGHTING); + glDisable(GL_COLOR_MATERIAL); + glEnable(GL_SCISSOR_TEST); + glEnableClientState(GL_VERTEX_ARRAY); + glEnableClientState(GL_TEXTURE_COORD_ARRAY); + glEnableClientState(GL_COLOR_ARRAY); + glEnable(GL_TEXTURE_2D); + glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); + //glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context where shaders may be bound + + // Setup viewport, orthographic projection matrix + // Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayMin is typically (0,0) for single viewport apps. + glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height); + glMatrixMode(GL_PROJECTION); + glPushMatrix(); + glLoadIdentity(); + glOrtho(draw_data->DisplayPos.x, draw_data->DisplayPos.x + draw_data->DisplaySize.x, draw_data->DisplayPos.y + draw_data->DisplaySize.y, draw_data->DisplayPos.y, -1.0f, +1.0f); + glMatrixMode(GL_MODELVIEW); + glPushMatrix(); + glLoadIdentity(); + + // Render command lists + ImVec2 pos = draw_data->DisplayPos; + for (int n = 0; n < draw_data->CmdListsCount; n++) + { + const ImDrawList* cmd_list = draw_data->CmdLists[n]; + const ImDrawVert* vtx_buffer = cmd_list->VtxBuffer.Data; + const ImDrawIdx* idx_buffer = cmd_list->IdxBuffer.Data; + glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, pos))); + glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, uv))); + glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, col))); + + for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++) + { + const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i]; + if (pcmd->UserCallback) + { + // User callback (registered via ImDrawList::AddCallback) + pcmd->UserCallback(cmd_list, pcmd); + } + else + { + ImVec4 clip_rect = ImVec4(pcmd->ClipRect.x - pos.x, pcmd->ClipRect.y - pos.y, pcmd->ClipRect.z - pos.x, pcmd->ClipRect.w - pos.y); + if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f) + { + // Apply scissor/clipping rectangle + glScissor((int)clip_rect.x, (int)(fb_height - clip_rect.w), (int)(clip_rect.z - clip_rect.x), (int)(clip_rect.w - clip_rect.y)); + + // Bind texture, Draw + glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId); + glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer); + } + } + idx_buffer += pcmd->ElemCount; + } + } + + // Restore modified state + glDisableClientState(GL_COLOR_ARRAY); + glDisableClientState(GL_TEXTURE_COORD_ARRAY); + glDisableClientState(GL_VERTEX_ARRAY); + glBindTexture(GL_TEXTURE_2D, (GLuint)last_texture); + glMatrixMode(GL_MODELVIEW); + glPopMatrix(); + glMatrixMode(GL_PROJECTION); + glPopMatrix(); + glPopAttrib(); + glPolygonMode(GL_FRONT, (GLenum)last_polygon_mode[0]); glPolygonMode(GL_BACK, (GLenum)last_polygon_mode[1]); + 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]); +} + +bool ImGui_ImplOpenGL2_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 (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory. + + // 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 = (ImTextureID)(intptr_t)g_FontTexture; + + // Restore state + glBindTexture(GL_TEXTURE_2D, last_texture); + + return true; +} + +void ImGui_ImplOpenGL2_DestroyFontsTexture() +{ + if (g_FontTexture) + { + ImGuiIO& io = ImGui::GetIO(); + glDeleteTextures(1, &g_FontTexture); + io.Fonts->TexID = 0; + g_FontTexture = 0; + } +} + +bool ImGui_ImplOpenGL2_CreateDeviceObjects() +{ + return ImGui_ImplOpenGL2_CreateFontsTexture(); +} + +void ImGui_ImplOpenGL2_DestroyDeviceObjects() +{ + ImGui_ImplOpenGL2_DestroyFontsTexture(); +} |