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Examples: OpenGL2/3: Save/setup/restore viewport as part of render function. Update SDL example to match GL2 one. (fix #392)

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This commit is contained in:
ocornut
2015-10-30 15:44:47 +01:00
parent 6ffe0fddbf
commit 980ca286fe
3 changed files with 22 additions and 11 deletions
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20
examples/sdl_opengl_example/imgui_impl_sdl.cpp
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@ -22,8 +22,9 @@ static GLuint g_FontTexture = 0;
void ImGui_ImplSdl_RenderDrawLists(ImDrawData* draw_data)
{
// We are using the OpenGL fixed pipeline to make the example code simpler to read!
// A probable faster way to render would be to collate all vertices from all cmd_lists into a single vertex buffer.
// Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers.
GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT | GL_TRANSFORM_BIT);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
@ -36,13 +37,17 @@ void ImGui_ImplSdl_RenderDrawLists(ImDrawData* draw_data)
glEnable(GL_TEXTURE_2D);
//glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context
// Setup orthographic projection matrix
const float width = ImGui::GetIO().DisplaySize.x;
const float height = ImGui::GetIO().DisplaySize.y;
// Handle cases of screen coordinates != from framebuffer coordinates (e.g. retina displays)
ImGuiIO& io = ImGui::GetIO();
float fb_height = io.DisplaySize.y * io.DisplayFramebufferScale.y;
draw_data->ScaleClipRects(io.DisplayFramebufferScale);
// Setup viewport, orthographic projection matrix
glViewport(0, 0, (GLsizei)io.DisplaySize.x, (GLsizei)io.DisplaySize.y);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0.0f, width, height, 0.0f, -1.0f, +1.0f);
glOrtho(0.0f, io.DisplaySize.x, io.DisplaySize.y, 0.0f, -1.0f, +1.0f);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
@ -68,7 +73,7 @@ void ImGui_ImplSdl_RenderDrawLists(ImDrawData* draw_data)
else
{
glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
glScissor((int)pcmd->ClipRect.x, (int)(height - pcmd->ClipRect.w), (int)(pcmd->ClipRect.z - pcmd->ClipRect.x), (int)(pcmd->ClipRect.w - pcmd->ClipRect.y));
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, GL_UNSIGNED_SHORT, idx_buffer);
}
idx_buffer += pcmd->ElemCount;
@ -80,12 +85,13 @@ void ImGui_ImplSdl_RenderDrawLists(ImDrawData* draw_data)
glDisableClientState(GL_COLOR_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);
glBindTexture(GL_TEXTURE_2D, 0);
glBindTexture(GL_TEXTURE_2D, last_texture);
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glPopAttrib();
glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
}
static const char* ImGui_ImplSdl_GetClipboardText()