ImDrawCallback_ResetRenderState, Examples: Added support for reset render state callback. (#2037, #1639, #2452)

This commit is contained in:
omar
2019-04-30 22:15:59 +02:00
parent 3fbc0b7a9e
commit 5c1cd5c8c7
10 changed files with 394 additions and 294 deletions

View File

@ -150,6 +150,56 @@ void ImGui_ImplOpenGL3_NewFrame()
ImGui_ImplOpenGL3_CreateDeviceObjects();
}
static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height, GLuint vertex_array_object)
{
// 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);
#ifdef GL_POLYGON_MODE
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
#endif
// 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);
float L = draw_data->DisplayPos.x;
float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
float T = draw_data->DisplayPos.y;
float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
const float ortho_projection[4][4] =
{
{ 2.0f/(R-L), 0.0f, 0.0f, 0.0f },
{ 0.0f, 2.0f/(T-B), 0.0f, 0.0f },
{ 0.0f, 0.0f, -1.0f, 0.0f },
{ (R+L)/(L-R), (T+B)/(B-T), 0.0f, 1.0f },
};
glUseProgram(g_ShaderHandle);
glUniform1i(g_AttribLocationTex, 0);
glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
#ifdef GL_SAMPLER_BINDING
glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
#endif
(void)vertex_array_object;
#ifndef IMGUI_IMPL_OPENGL_ES2
glBindVertexArray(vertex_array_object);
#endif
// Bind vertex/index buffers and setup attributes for ImDrawVert
glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle);
glEnableVertexAttribArray(g_AttribLocationVtxPos);
glEnableVertexAttribArray(g_AttribLocationVtxUV);
glEnableVertexAttribArray(g_AttribLocationVtxColor);
glVertexAttribPointer(g_AttribLocationVtxPos, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos));
glVertexAttribPointer(g_AttribLocationVtxUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv));
glVertexAttribPointer(g_AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col));
}
// OpenGL3 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.
@ -195,55 +245,14 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
clip_origin_lower_left = false;
#endif
// 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);
#ifdef GL_POLYGON_MODE
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
#endif
// 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);
float L = draw_data->DisplayPos.x;
float R = draw_data->DisplayPos.x + draw_data->DisplaySize.x;
float T = draw_data->DisplayPos.y;
float B = draw_data->DisplayPos.y + draw_data->DisplaySize.y;
const float ortho_projection[4][4] =
{
{ 2.0f/(R-L), 0.0f, 0.0f, 0.0f },
{ 0.0f, 2.0f/(T-B), 0.0f, 0.0f },
{ 0.0f, 0.0f, -1.0f, 0.0f },
{ (R+L)/(L-R), (T+B)/(B-T), 0.0f, 1.0f },
};
glUseProgram(g_ShaderHandle);
glUniform1i(g_AttribLocationTex, 0);
glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
#ifdef GL_SAMPLER_BINDING
glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
#endif
// Setup desired GL state
// Recreate the VAO every time (this is to easily allow multiple GL contexts to be rendered to. VAO are not shared among GL contexts)
// The renderer would actually work without any VAO bound, but then our VertexAttrib calls would overwrite the default one currently bound.
#ifndef IMGUI_IMPL_OPENGL_ES2
GLuint vertex_array_object = 0;
#ifndef IMGUI_IMPL_OPENGL_ES2
glGenVertexArrays(1, &vertex_array_object);
glBindVertexArray(vertex_array_object);
#endif
// Bind vertex/index buffers and setup attributes for ImDrawVert
glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle);
glEnableVertexAttribArray(g_AttribLocationVtxPos);
glEnableVertexAttribArray(g_AttribLocationVtxUV);
glEnableVertexAttribArray(g_AttribLocationVtxColor);
glVertexAttribPointer(g_AttribLocationVtxPos, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos));
glVertexAttribPointer(g_AttribLocationVtxUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv));
glVertexAttribPointer(g_AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col));
ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
// Will project scissor/clipping rectangles into framebuffer space
ImVec2 clip_off = draw_data->DisplayPos; // (0,0) unless using multi-viewports
@ -262,10 +271,14 @@ void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
{
const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
if (pcmd->UserCallback)
if (pcmd->UserCallback != NULL)
{
// User callback (registered via ImDrawList::AddCallback)
pcmd->UserCallback(cmd_list, pcmd);
// User callback, registered via ImDrawList::AddCallback()
// (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
ImGui_ImplOpenGL3_SetupRenderState(draw_data, fb_width, fb_height, vertex_array_object);
else
pcmd->UserCallback(cmd_list, pcmd);
}
else
{