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Examples: OpenGL3: simplified code. Upload each vertex array separately. (cf #264)

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This commit is contained in:
ocornut 2015-07-08 08:27:36 -06:00
parent 1cd391146d
commit e3b9a61883
1 changed files with 18 additions and 27 deletions
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45
examples/opengl3_example/imgui_impl_glfw_gl3.cpp
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@ -56,38 +56,29 @@ static void ImGui_ImplGlfwGL3_RenderDrawLists(ImDrawData* draw_data)
glUseProgram(g_ShaderHandle);
glUniform1i(g_AttribLocationTex, 0);
glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
// Grow our buffer according to what we need
glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
int needed_vtx_size = draw_data->TotalVtxCount * sizeof(ImDrawVert);
if (g_VboSize < needed_vtx_size)
{
g_VboSize = needed_vtx_size + 5000 * sizeof(ImDrawVert); // Grow buffer
glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)g_VboSize, NULL, GL_STREAM_DRAW);
}
// Copy and convert all vertices into a single contiguous buffer
unsigned char* vtx_data = (unsigned char*)glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
if (!vtx_data)
return;
for (int n = 0; n < draw_data->CmdListsCount; n++)
{
const ImDrawList* cmd_list = draw_data->CmdLists[n];
memcpy(vtx_data, &cmd_list->VtxBuffer[0], cmd_list->VtxBuffer.size() * sizeof(ImDrawVert));
vtx_data += cmd_list->VtxBuffer.size() * sizeof(ImDrawVert);
}
glUnmapBuffer(GL_ARRAY_BUFFER);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(g_VaoHandle);
int vtx_offset = 0;
for (int n = 0; n < draw_data->CmdListsCount; n++)
{
const ImDrawList* cmd_list = draw_data->CmdLists[n];
const ImDrawIdx* idx_buffer = &cmd_list->IdxBuffer.front();
const ImDrawCmd* pcmd_end = cmd_list->CmdBuffer.end();
for (const ImDrawCmd* pcmd = cmd_list->CmdBuffer.begin(); pcmd != pcmd_end; pcmd++)
glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle);
int needed_vtx_size = cmd_list->VtxBuffer.size() * sizeof(ImDrawVert);
if (g_VboSize < needed_vtx_size)
{
// Grow our buffer if needed
g_VboSize = needed_vtx_size + 2000 * sizeof(ImDrawVert);
glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)g_VboSize, NULL, GL_STREAM_DRAW);
}
unsigned char* vtx_data = (unsigned char*)glMapBufferRange(GL_ARRAY_BUFFER, 0, needed_vtx_size, GL_MAP_WRITE_BIT | GL_MAP_INVALIDATE_BUFFER_BIT);
if (!vtx_data)
continue;
memcpy(vtx_data, &cmd_list->VtxBuffer[0], cmd_list->VtxBuffer.size() * sizeof(ImDrawVert));
glUnmapBuffer(GL_ARRAY_BUFFER);
for (const ImDrawCmd* pcmd = cmd_list->CmdBuffer.begin(); pcmd != cmd_list->CmdBuffer.end(); pcmd++)
{
if (pcmd->UserCallback)
{
@ -97,15 +88,15 @@ static void ImGui_ImplGlfwGL3_RenderDrawLists(ImDrawData* draw_data)
{
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));
glDrawElementsBaseVertex(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, GL_UNSIGNED_SHORT, idx_buffer, vtx_offset);
glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, GL_UNSIGNED_SHORT, idx_buffer);
}
idx_buffer += pcmd->ElemCount;
}
vtx_offset += cmd_list->VtxBuffer.size();
}
// Restore modified state
glBindVertexArray(0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glUseProgram(last_program);
glDisable(GL_SCISSOR_TEST);
glBindTexture(GL_TEXTURE_2D, last_texture);